DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Specification
The disclosure is objected to because of the following informalities:
In paragraph [0153], the sentence, “The five output beams (125a,… ) and the three corresponding input beams (135a, 135b, 135c, 135d, 135e)…” should read, “The five output beams (125a,… ) and the five corresponding input beams (135a, 135b, 135c, 135d, 135e)…”.
In paragraph [0227], the phrase, “and the diffractive beam deflector 122 may be a diffractive beam deflector.” should likely be updated to convey the intended meaning, as the current statement appears redundant.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claims 13 and 14 are rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends.
Claim 13 contains the limitation, “to produce an amplified pulse of light that includes each of the plurality of different wavelengths”, which is in contradiction to the limitation of claim 1, “each emitted pulse of light having a particular wavelength of a plurality of different wavelengths”. Thus, claim 13 does not include all of the limitation of claim 1. As claim 13 is dependent upon claim 1, through claims 8 and 4, it fails to include all of the limitations upon which it depends.
Claim 14 is rejected due to claim dependency.
Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claim(s) 1-4, 6, 8, 16, 23-25, and 28 is/are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Li (WO 2023044538 A1).
Regarding claim 1, Li teaches:
A lidar system comprising ([Pg. 6, Line 28] “Fig. 1 illustrates an arrangement of a spatial profiling system 100”):
a wavelength-tunable light source configured to emit pulses of light, each emitted pulse of light having a particular wavelength of a plurality of different wavelengths ([Pg. 8, Line 13 - Pg. 9, Line 12] “Fig. 2 illustrates an arrangement of the light source 101. In this example, the light source 101 may include a wavelength-tunable light source, such as a wavelength-tunable laser diode, providing light of a tunable wavelength… The light source 101 accordingly is configured to provide outgoing light at a selected one or more of the multiple wavelength channels (each represented by its respective centre wavelength Xi, X2, ... XN)… In some embodiments, the light source 101 emits pulses of light”);
a scanner configured to scan the emitted pulses of light across a field of regard of the lidar system (FIG. 6A, beam director 104), the scanner comprising:
a beam deflector configured to angularly deflect each emitted pulse of light along a first scan axis according to the particular wavelength of the emitted pulse of light ([Pg. 12, Lines 11 - 21] “At step 402, the light of multiple wavelengths from the light transceiver 103 is steered into different directions across a first dimension based on wavelength…. Step 402 may be performed by a dispersive component including one or more dispersive elements”; FIG. 6A, dispersive component 504); and
a scan mirror configured to scan the emitted pulses of light along a second scan axis different from the first scan axis ([Pg. 19, Lines 19-29] “Figure 6A illustrates an optical system 600, which includes the optical system 500C additionally configured to provide for beam direction across another dimension, for instance the first dimension referred to in Fig. 4. In other words, the optical system 600 is configured to implement steps 402 to 408 of Fig. 4… To achieve two-dimensional scanning, the beam director 104 also includes a scanning component 512, to further steer the light beams… over a dimension that is, or at least includes a substantial component that is, orthogonal to the second dimension… ”);
a receiver configured to: detect a received pulse of light, the received pulse of light comprising a portion of one of the emitted pulses of light scattered by a target located a distance from the lidar system ([Pg. 7, Line 22 - Pg. 8, Line 2] “If the outgoing light hits an object, at least part of the outgoing light may be reflected (represented in striped arrows), e.g. scattered, by the object back to the beam director 104 as incoming light. The beam director 104 directs the incoming light to the reception optics (e.g. the light transceiver 103), which collects the light and passes it to a light detector circuitry 105.”); and
determine a time of arrival of the received pulse of light ([Pg. 8, Lines 3-12] “… The light detector circuitry 105 generates incoming electrical signals that are representative of the detected incoming light… The incoming digital signals are received and processed by a control system 107.”); and
a processor configured to determine the distance from the lidar system to the target based on the time of arrival of the received pulse of light ([Pg. 8, Lines 3-12] “The control system 107 may determine a round trip time for the light based on its control or knowledge of the outgoing light and based on the incoming light signals.”; [Pg. 5, Line 23 - Pg. 6, Line 4] “By determining the time it takes for the light to make a round trip to and from, and hence the distance of, reflecting surfaces within a field of view (FOV), an estimation of the spatial profile of the environment may be formed.”).
Regarding claim 2, Li teaches the lidar system of claim 1, as described above, and further teaches:
wherein the light source comprises: a wavelength-tunable seed laser diode configured to produce seed light at the plurality of different wavelengths ([Pg. 8, Line 13 - Pg. 9, Line 12] “Fig. 2 illustrates an arrangement of the light source 101. In this example, the light source 101 may include a wavelength-tunable light source, such as a wavelength-tunable laser diode… the light source 101 includes a modulator 204 for imparting a time-varying profile on the outgoing light.”); and
an optical amplifier configured to amplify the seed light to produce the emitted pulses of light, wherein the optical amplifier comprises a semiconductor optical amplifier (SOA), a fiber- optic amplifier, or a SOA followed by a fiber-optic amplifier ([Pg. 9, Lines 13-25] “In one example, the modulator 204 is a semiconductor optical amplifier (SOA) or a Mach Zehnder modulator integrated on a laser diode of the light source 101.”).
Regarding claim 3, Li teaches the lidar system of claim 2, as described above, and further teaches:
wherein the wavelength-tunable seed laser diode comprises a distributed Bragg reflector (DBR) laser configured to produce the seed light at the plurality of different wavelengths ([Pg. 9, Lines 26-31] “In some embodiments the light source 101, optical amplifier 102 and a modulator are provided by a sampled-grating distributed Bragg reflector (SG-DBR) laser.”).
Regarding claim 4, Li teaches the lidar system of claim 1, as described above, and further teaches:
wherein the light source comprises: a sampled-grating distributed Bragg reflector (SG-DBR) laser configured to produce seed light at the plurality of different wavelengths ([Pg. 9, Lines 26-31] “In some embodiments the light source 101, optical amplifier 102 and a modulator are provided by a sampled-grating distributed Bragg reflector (SG-DBR) laser.”); and
a semiconductor optical amplifier (SOA) configured to amplify the seed light produced by the SG-DBR laser ([Pg. 9, Lines 13-25] “In one example, the modulator 204 is a semiconductor optical amplifier (SOA) or a Mach Zehnder modulator integrated on a laser diode of the light source 101.”).
Regarding claim 6, Li teaches the lidar system of claim 4, as described above, and further teaches:
wherein the SG-DBR laser and the SOA are integrated together, wherein the seed light produced by the SG-DBR laser is coupled from a front mirror of the SG-DBR laser directly into an input end of a waveguide of the SOA ([Pg. 9, Lines 13-25] “In one example, the modulator 204 is a semiconductor optical amplifier (SOA) or a Mach Zehnder modulator integrated on a laser diode of the light source 101.”).
Regarding claim 8, Li teaches the lidar system of claim 4, as described above, and further teaches:
the SG-DBR laser comprises a back mirror, a phase section, a gain section, and a front mirror, wherein the phase and gain sections are disposed between the front and back mirrors; and the light source further comprises an electronic driver configured to supply particular combinations of electrical currents to the back mirror, the phase section, the gain section, and the front mirror, wherein each particular combination of electrical currents causes the SG-DBR laser to produce the seed light at one of the plurality of different wavelengths (This limitation states the inherent and basic functioning of a SG-DBR. See, for example, He (US 20220200230 A1), [0057-58] “An entire current control module of the SG-DBR semiconductor laser device is shown in FIG. 6, and includes a rear mirror end, a phase end, a gain end, a front mirror end, and an optical amplifier end. The front mirror end, the rear mirror end, and the phase end work in a high-bandwidth mode with a current 14, a current I1, and a current I2, to control output frequency of the laser device at a high speed. The gain end and the optical amplifier end work in a low-bandwidth mode with a current 13 and a current 15, to control the output power of the laser device.”).
Regarding claim 16, Li teaches the lidar system of claim 1, as described above, and further teaches:
wherein: the received pulse of light is part of an input beam of light, the input beam of light comprising a plurality of received pulses of light ([Pg. 5, Line 23 - Pg. 6, Line 4] “LiDAR involves transmitting light into the environment and subsequently detecting the light returned by the environment.”; [Pg. 8, Line 13 - Pg. 9, Line 12] “In some embodiments, the light source 101 emits pulses of light”); and
the input beam of light, prior to being directed to the receiver, travels through the scanner wherein the beam deflector is further configured to angularly deflect each received pulse of light according to wavelength, wherein upon exiting the scanner, the received pulses of light are directed to the receiver along a common propagation axis ([Pg. 7, Line 22 - Pg. 8, Line 2] “In some embodiments the beam director 104 includes bidirectional components, whereby both the outgoing light to the environment and incoming light from the environment traverse substantially the same path through the beam director 104, in opposite directions. Figure 1 represents this by the bidirectional arrow for the light traversing free space.” Note that this description entails the received light passing back through dispersive component 504, which is part of the embodiment of beam director 104.); and
the receiver comprises a detector configured to detect at least a portion of each of the received pulses of light ([Pg. 8, Lines 3-12] “The light detector circuitry 105 includes one or more photodetectors… The light detector circuitry 105 generates incoming electrical signals that are representative of the detected incoming light”).
Regarding claim 23, Li teaches the lidar system of claim 1, as described above, and further teaches:
wherein the beam deflector comprises a diffractive optical element ([Pg. 12, Lines 11 - 21] “Step 402 may be performed by a dispersive component including one or more dispersive elements… In some embodiments the one or more dispersive elements include one or more gratings.”).
Regarding claim 24, Li teaches the lidar system of claim 1, as described above, and further teaches:
wherein the beam deflector comprises a diffraction grating, a prism, a grism, a photonic crystal, an arrayed waveguide grating, or a holographic optical element ([Pg. 12, Lines 11 - 21] “In some embodiments the one or more dispersive elements include one or more gratings. In some embodiments the one or more dispersive elements include or consist of an arrayed waveguide grating. In some embodiments the one or more dispersive elements include one or more refractive components, such as a prism.”).
Regarding clam 25, Li teaches the lidar system of claim 1, as described above, and further teaches:
wherein the scan mirror comprises a polygon mirror configured to rotate to scan the emitted pulses of light along the second scan axis ([Pg. 20, Lines 6-12] “In one example, the scanning component 512 is reflector in the form of a polygon mirror. The polygon mirror may rotate continuously.”),
wherein the polygon mirror comprises a plurality of reflective surfaces angularly offset from one another along a periphery of the polygon mirror, each reflective surface configured to reflect, in sequence as the polygon mirror rotates, a portion of the emitted pulses of light ([Pg. 20, Line 30 - Pg. 1, Line 4] “Figs. 7A and 7B illustrate the beam director 600 of Fig. 6A with a polygon mirror 512a as the scanning component… The polygon mirror 512a is rotated about an axis A, which is located at the geometric centre of the polygon mirror 512a. With the rotation, the relative angle of the reflecting surface of the polygon mirror 512a changes. As a result, the outgoing light from the light source 101 or the optical amplifier 102 is steered.” Note the angular offset associated with the polygon shape.).
Regarding clam 28, Li teaches the lidar system of claim 1, as described above, and further teaches:
wherein the second scan axis is substantially orthogonal to the first scan axis ([Pg. 19, Lines 19-29] “To achieve two-dimensional scanning, the beam director 104 also includes a scanning component 512, to further steer the light beams… over a dimension that is, or at least includes a substantial component that is, orthogonal to the second dimension… ”).
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li in view of Paschotta (Tapered Amplifiers. Dr. Rüdiger Paschotta. rp-photonics.com/tapered_amplifiers.html accessed from the Wayback Machine dated 10/19/2021.).
Regarding claim 5, Li teaches the lidar system of claim 4, as described above, but does not explicitly teach:
wherein the SOA comprises a tapered optical waveguide extending from an input end of the SOA to an output end of the SOA, wherein a width of the tapered optical waveguide increases from the input end to the output end.
Paschotta teaches that the use of a tapered SOA is common practice with wavelength-tunable laser diodes ([Pg. 2] “It is common to use a tapered amplifier as part of a master oscillator power amplifier (MOPA) system (see Figure 2). The seed laser is normally a laser diode, e.g. a distributed-feedback laser with narrow linewidth, or some other kind of laser diode which may be wavelength-tunable.”). Thus teaching the limitation:
wherein the SOA comprises a tapered optical waveguide extending from an input end of the SOA to an output end of the SOA ([Pg. 1] “The term is mostly used in conjunction with semiconductor optical amplifiers (SOAs)”), wherein a width of the tapered optical waveguide increases from the input end to the output end ([Pg. 1] “Thereafter, the light gets into the taper region, the width of which may linearly or nonlinearly be increased towards the output end”).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have modified the lidar system of Li with the tapered SOA taught by Paschotta as one of the well-known amplifier configurations with predictable results.
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li in view of Shah et al. (US 10845480 B1), hereinafter Shah.
Regarding claim 7, Li teaches the lidar system of claim 4, as described above, but does not teach:
wherein the light source further comprises a fiber-optic amplifier configured to receive the amplified seed light from the SOA and further amplify the amplified seed light to produce the emitted pulses of light.
Shah, in the same field of endeavor, teaches further amplifying the laser pulse with a fiber amplifier, thus teaching:
wherein the light source further comprises a fiber-optic amplifier configured to receive the amplified seed light from the SOA and further amplify the amplified seed light to produce the emitted pulses of light ([Col. 23, Lines 51-67] “FIG. 7… a light source 110 of a lidar system 100 may include: (i) a seed laser diode 400 that produces seed light 405, (ii) a SOA 410 that amplifies the seed light 405 to produce amplified seed light 406, and (iii) a fiber-optic amplifier 500 that further amplifies the amplified seed light 406 to produce an output beam 125 that includes the further-amplified seed optical signal.”).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have modified the lidar system of Li with the additional fiber amplifier taught by Shah to provide more power to the light pulses.
Claim(s) 9, 11-12, and 31 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li in view of Villenueve (US 10003168 B1).
Regarding claim 9, Li teaches the lidar system of claim 8, as described above, and further teaches:
[…]
the electrical currents supplied to the back mirror, the phase section, and the front mirror of the SG-DBR laser cause […] the seed […] light to have one of the plurality of different wavelengths (As discussed above with regard to claim 8, this aspect of the limitation is inherent to the function of the SG-DBR. See, for example, He (US 20220200230 A1), [0057-58]); and
the electronic driver is further configured to supply pulses of electrical current to the SOA, wherein each pulse of electrical current supplied to the SOA causes the SOA to optically amplify […] the seed […] light to produce one of the emitted pulses of light, ([Pg. 9, Lines 13-25] “The electrical current applied to the SOA may be varied over time to vary the amplification of the CW light produced by the laser over time, which in turn provide outgoing light with a time -varying intensity profile.”),
each emitted pulse of light having one wavelength of the plurality of different wavelengths, the one wavelength matching that of a corresponding seed pulse of light ([Pg. 8, Line 13 - Pg. 9, Line 12] “The light source 101 accordingly is configured to provide outgoing light at a selected one or more of the multiple wavelength channels (each represented by its respective centre wavelength Xi, X2, ... XN)… In some embodiments, the light source 101 emits pulses of light”).
Li does not explicitly teach:
wherein: the electrical current supplied to the gain section of the SG-DBR laser comprises pulses of electrical current, wherein each pulse of electrical current supplied to the gain section causes the SG-DBR laser to produce a seed pulse of light;
the electrical currents supplied to the back mirror, the phase section, and the front mirror of the SG-DBR laser cause each of the seed pulses of light to have one of the plurality of different wavelengths; and
the electronic driver is further configured to supply pulses of electrical current to the SOA, wherein each pulse of electrical current supplied to the SOA causes the SOA to optically amplify one of the seed pulses of light to produce one of the emitted pulses of light,
Villenueve, in the same field of endeavor, teaches the well-known variety of options for creating pulses from a seed laser plus SOA combination, thus teaching:
wherein: the electrical current supplied to the gain section of the SG-DBR laser comprises pulses of electrical current, wherein each pulse of electrical current supplied to the gain section causes the SG-DBR laser to produce a seed pulse of light; ([Col. 58, Line 59 - Col. 59, Line 8] “As an example, a seed laser may produce optical pulses that are coupled into a SOA. The current supplied to the SOA may be a substantially constant DC current, or the current supplied to the SOA may be pulsed at a pulse frequency that matches the pulse repetition frequency of the seed laser (e.g., the SOA current is pulsed so that optical gain is only provided when a seed-laser pulse is present).”)
Thus, the combination of Li in view of Villenueve would teach the remaining limitations, as the teachings of Li would now be operating on seed pulses:
the electrical currents supplied to the back mirror, the phase section, and the front mirror of the SG-DBR laser cause each of the seed pulses of light to have one of the plurality of different wavelengths; and
the electronic driver is further configured to supply pulses of electrical current to the SOA, wherein each pulse of electrical current supplied to the SOA causes the SOA to optically amplify one of the seed pulses of light to produce one of the emitted pulses of light,
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have modified the lidar system of Li with the pulse-driving of the seed laser as taught by Villenueve as one of the known and predictable methods for producing pulsed output light.
Regarding claim 11, Li teaches the lidar system of claim 8, as described above, and further teaches:
[…]
the electrical currents supplied to the back mirror, the phase section, and the front mirror of the SG-DBR laser cause the seed […] light to have a time-varying wavelength that includes each of the plurality of different wavelengths (As discussed above with regard to claim 8, this aspect of the limitation is inherent to the function of the SG-DBR. See, for example, He (US 20220200230 A1), [0057-58]);
the electronic driver is further configured to supply a plurality of pulses of electrical current to the SOA while the […] electrical current is supplied to the gain section of the SG-DBR laser, wherein each pulse of electrical current supplied to the SOA causes the SOA to optically amplify a temporal portion of the wavelength-varying seed […] light to produce one of the emitted pulses of light, the emitted pulse of light having a wavelength corresponding to a wavelength of the temporal portion of the seed pulse of light ([Pg. 9, Lines 13-25] “The electrical current applied to the SOA may be varied over time to vary the amplification of the CW light produced by the laser over time, which in turn provide outgoing light with a time -varying intensity profile.”).
Li does not explicitly teach:
wherein: the electrical current supplied to the gain section of the SG-DBR laser comprises a pulse of electrical current that causes the SG-DBR laser to produce a seed pulse of light;
the electrical currents supplied to the back mirror, the phase section, and the front mirror of the SG-DBR laser cause the seed pulse of light to have a time-varying wavelength that includes each of the plurality of different wavelengths;
the electronic driver is further configured to supply a plurality of pulses of electrical current to the SOA while the pulse of electrical current is supplied to the gain section of the SG-DBR laser, wherein each pulse of electrical current supplied to the SOA causes the SOA to optically amplify a temporal portion of the wavelength-varying seed pulse of light to produce one of the emitted pulses of light, the emitted pulse of light having a wavelength corresponding to a wavelength of the temporal portion of the seed pulse of light.
Villenueve, in the same field of endeavor, teaches the well-known variety of options for creating pulses from a seed laser plus SOA combination, thus teaching:
wherein: the electrical current supplied to the gain section of the SG-DBR laser comprises a pulse of electrical current that causes the SG-DBR laser to produce a seed pulse of light ([Col. 58, Line 59 - Col. 59, Line 8] “As an example, a seed laser may produce optical pulses that are coupled into a SOA. The current supplied to the SOA may be a substantially constant DC current, or the current supplied to the SOA may be pulsed at a pulse frequency that matches the pulse repetition frequency of the seed laser (e.g., the SOA current is pulsed so that optical gain is only provided when a seed-laser pulse is present).”);
Thus, Li teaches the consideration of a continuous seed laser which emits a varied wavelength with time, and the combination of Li and Villenueve teaches the consideration of a pulsed seed laser with variable wavelengths for each pulse. The claimed invention is simply an example which exists in the “middle ground” between these two modes of operation which performs in a predictable way based on an understanding of each of these two modes. Based on the teachings of Li and Villenueve, it would have been obvious to one of ordinary skill to try any of the finite durations of seed pulse which cover an integer number of eventual output pulses, as dictated by the amplifier, thus encompassing the remaining limitations when incorporated into the lidar system of Li:
the electrical currents supplied to the back mirror, the phase section, and the front mirror of the SG-DBR laser cause the seed pulse of light to have a time-varying wavelength that includes each of the plurality of different wavelengths;
the electronic driver is further configured to supply a plurality of pulses of electrical current to the SOA while the pulse of electrical current is supplied to the gain section of the SG-DBR laser, wherein each pulse of electrical current supplied to the SOA causes the SOA to optically amplify a temporal portion of the wavelength-varying seed pulse of light to produce one of the emitted pulses of light, the emitted pulse of light having a wavelength corresponding to a wavelength of the temporal portion of the seed pulse of light.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have modified the lidar system of Li with a seed laser pulsing which spans multiple amplifier pulses as one of the finite and predictable options which are obvious to in view of the continuous-wave operation of Li and the pulsed operation as taught by Villenueve.
Regarding claim 12, Li in view of Villenueve teaches the lidar system of claim 11, as described above, and further teaches:
wherein: the electronic driver is configured to supply P pulses of electrical current to the SOA while the pulse of electrical current is supplied to the gain section of the SG-DBR laser so that the SOA optically amplifies P temporal portions of the wavelength-varying seed pulse of light to produce P of the emitted pulses of light (In the context of the “obvious to try” configuration as presented in claim 11, the seed pulse covers an integer number of electrical pulses of the SOA, this integer number corresponds to “P”.),
wherein P is an integer greater than or equal to 2 (In the context of the “obvious to try” configuration as presented in claim 11, the value of P lies somewhere between 1, as taught by Villenueve, and “all” as taught by the continuous-wave operation of Li. Thus meeting the limitation of greater than or equal to 2.);
the P emitted pulses of light have an average duration of Δt (The emitted light pulses inherently have some time duration, which corresponds to the claimed Δt.); and
the wavelength-varying seed pulse of light has a duration greater than or equal to P x Δt (As the teachings of Li and Villenueve do not involve overlapping output pulses, the seed pulse of the “obvious to try” configuration as presented in claim 11 would naturally have a duration of at least P x Δt, as this would only not be the case if the P output pulses overlapped in time.).
Regarding claim 31, Li teaches the lidar system of claim 1, as described above, but does not explicitly teach:
wherein the emitted pulses of light have optical characteristics comprising: a pulse energy between 0.01 pJ and 100 pJ;
a pulse repetition frequency between 80 kHz and 10 MHz; and
a pulse duration between 1 ns and 100 ns.
Villenueve, in the same field of endeavor, teaches lidar pulse characteristics, including:
wherein the emitted pulses of light have optical characteristics comprising: a pulse energy between 0.01 pJ and 100 pJ ([Col. 4, Lines 1-24] “As another example, output beam 125 may include pulses with a pulse energy of approximately 0.01 μJ, 0.1 μJ, 1 μJ, 10 μJ, 100 μJ, 1 mJ, or any other suitable pulse energy.” Note that lower pulse energies are a reasonable consideration, in particular when accepting any associated decrease in performance, e.g. reduced maximum sensing distance.);
a pulse repetition frequency between 80 kHz and 10 MHz ([Col. 3, Lines 45-67] “In particular embodiments, light source 110 may include a pulsed laser… As another example, light source 110 may be a pulsed laser that produces pulses at a pulse repetition frequency of approximately 100 kHz to 5 MHz or a pulse period (e.g., a time between consecutive pulses) of approximately 200 ns to 10 μs.”); and
a pulse duration between 1 ns and 100 ns ([Col. 3, Lines 45-67] “In particular embodiments, light source 110 may include a pulsed laser. As an example, light source 110 may be a pulsed laser configured to produce or emit pulses of light with a pulse duration or pulse width of approximately 10 picoseconds (ps) to 20 nanoseconds (ns).”).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have operated the lidar system of Li with the pulse characteristics as considered by Villenueve, as a selection of choices from a finite range of predictable options.
Claim(s) 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li and Villenueve applied to claim 9 above, and further in view of Wood et al. (US 11493753 B1), hereinafter Wood.
Regarding claim 10, Li in view of Villenueve teaches the lidar system of claim 9, as described above, but does not explicitly teach:
wherein the electrical currents supplied to the back mirror, the phase section, and the front mirror of the SG-DBR laser are configured so that the emitted pulses of light are emitted in a non-sequential wavelength order.
Wood, in the field of variable-wavelength scanning, teaches:
wherein the electrical currents supplied to the back mirror, the phase section, and the front mirror of the SG-DBR laser are configured so that the emitted pulses of light are emitted in a non-sequential wavelength order ([Col. 14, Lines 29-55] “Encryption (encoding) of an image generated by the optical system 10 may be accomplished in a simple and natural way… the pattern of wavelength-tuned steps resulting in angle-tuned steps does not need to be operated in sequence. FIG. 13A shows such an example”; [Col. 15, Line 56 - Col. 16, Line 8] “As with the above imaging example, encryption (encoding) may be implemented via a unique or random choice for the wavelength stepping (hopping) pattern in time. FIG. 17 describes elements of this process, where the encoding may occur by rows (rather than by columns or within a column, as above). FIG. 17 shows that the choice of two sequential time sequenced wavelengths could be λ1 then λ2, or it could be λ1 then λ4, or it could be λ7 then λ6. And this only illustrates the first two time-sequenced wavelengths, so it is clear that the overall random or arbitrary time sequence for all wavelengths represents another form of wavelength hopping (frequency hopping), as above.”; FIGS 13-17).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have modified the lidar system of Li in view of Villenueve with the arbitrary wavelength emission of Wood to provide enhanced security (Wood: [Col. 14, Lines 29-55] “Such techniques would be useful, for instance, to provide unique encoding and security for a LiDAR system in automobiles analogous to the unique code for a personal cell phone. Uniquely, this form of laser-scanned image encryption results in both wavelength (spectral) encryption and angular (spatial) encryption, providing enhanced security that makes the system even more difficult to hack, spoof, or disable…”).
Claim(s) 13-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li in view of Villenueve and Rezk et al. (US 10775508 B1), hereinafter Rezk.
Regarding claim 13, Li teaches the lidar system of claim 8, as described above, and further teaches:
[…]
the electrical currents supplied to the back mirror, the phase section, and the front mirror of the SG-DBR laser cause the […] light to have a time-varying wavelength that includes each of the plurality of different wavelengths; and
the electronic driver is further configured to supply a pulse of electrical current to the SOA to optically amplify the wavelength-varying seed […] light to produce an amplified pulse of light […].
Li does not explicitly teach:
wherein: the electrical current supplied to the gain section of the SG-DBR laser comprises a pulse of electrical current that causes the SG-DBR laser to produce a seed pulse of light;
the electrical currents supplied to the back mirror, the phase section, and the front mirror of the SG-DBR laser cause the seed pulse of light to have a time-varying wavelength that includes each of the plurality of different wavelengths; and
the electronic driver is further configured to supply a pulse of electrical current to the SOA to optically amplify the wavelength-varying seed pulse of light to produce an amplified pulse of light that includes each of the plurality of different wavelengths.
Villenueve, in the same field of endeavor, teaches the well-known variety of options for creating pulses from a seed laser plus SOA combination, thus teaching:
wherein: the electrical current supplied to the gain section of the SG-DBR laser comprises a pulse of electrical current that causes the SG-DBR laser to produce a seed pulse of light ([Col. 58, Line 59 - Col. 59, Line 8] “As an example, a seed laser may produce optical pulses that are coupled into a SOA. The current supplied to the SOA may be a substantially constant DC current, or the current supplied to the SOA may be pulsed at a pulse frequency that matches the pulse repetition frequency of the seed laser (e.g., the SOA current is pulsed so that optical gain is only provided when a seed-laser pulse is present).”);
Thus, Li teaches the consideration of a continuous seed laser which emits a varied wavelength with time, and the combination of Li and Villenueve teaches the consideration of a pulsed seed laser with variable wavelengths for each pulse. It would have been obvious to try a configuration in the “middle ground” between these two modes of operation which performs in a predictable way based on an understanding of each of these two modes. Namely, based on the teachings of Li and Villenueve, it would have been obvious to one of ordinary skill to try any of the finite durations of seed pulse which cover an integer number of eventual output pulses, as dictated by the amplifier, thus encompassing the following limitations when incorporated into the lidar system of Li:
the electrical currents supplied to the back mirror, the phase section, and the front mirror of the SG-DBR laser cause the seed pulse of light to have a time-varying wavelength that includes each of the plurality of different wavelengths; and
the electronic driver is further configured to supply a pulse of electrical current to the SOA to optically amplify the wavelength-varying seed pulse of light to produce an amplified pulse of light […].
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have modified the lidar system of Li with a seed laser pulsing which spans multiple amplifier pulses as one of the finite and predictable options which are obvious to in view of the continuous-wave operation of Li and the pulsed operation as taught by Villenueve.
The combination still does not teach:
the electronic driver is further configured to supply a pulse of electrical current to the SOA to optically amplify the wavelength-varying seed pulse of light to produce an amplified pulse of light that includes each of the plurality of different wavelengths.
Rezk, in the same field of lidar scanning, teaches that even for time-of-flight style lidar systems, the emitted light may be delivered as a continuous beam of light which is, in effect, turned into pulses of light by scanning the continuous light over the field of view ([Col. 9, Lines 21-26] “As indicated at 1100, a light source of a transmit component of the remote sensing device emits a beam of light. For example, the beam may be a collimated, narrow beam emitted from a light source such as one or more lasers. In some embodiments, the light source may continuously emit the beam during the scan method of elements 1102-1118.”). It would reasonably be understood by one of ordinary skill in the art, that just as it is reasonable to emit individual pulses of light, or to emit a continuous beam of light, it would also be reasonable to emit pulses of light with respect to one scanning direction and continuous beams of light with respect to a second scanning direction, e.g. by emitting “long” pulses of light.
While Rezk contemplates this within the context of more traditional scanning mechanism, the fundamental concept that a continuously emitted beam may be spatially broken into separate pulses by the act of scanning the beam would apply to any scanning mechanism, and in the context of the spectrally scanned lidar system of Li in view of Villenueve, the continuously emitted, yet still scanned beam, would involve a light beam in which continuously transitions from one wavelength to another. Thus, the combination of Li in view of Villenueve, which teaches the variety of different ways one may pulse a seed and SOA combination, and Rezk, which teaches the viability of scanning a light beam which emits continuously in time, teaches the remaining limitation:
the electronic driver is further configured to supply a pulse of electrical current to the SOA to optically amplify the wavelength-varying seed pulse of light to produce an amplified pulse of light that includes each of the plurality of different wavelengths.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have modified the lidar system of Li in view of Villenueve with scan-separated pulses as taught by Rezk, as one of the known and predictable methods for emitting pulses of light into different spatial regions of a field of view.
Regarding claim 14, Li in view of Villenueve and Rezk teaches the lidar system of claim 13, as described above, and further teaches:
wherein the beam deflector angularly deflects the amplified pulse of light along the first scan axis to produce emitted pulses of light at the plurality of different wavelengths (The dispersive element of Li, by spatially separating light of different wavelengths into different angular regions of the field of view, would cause a light pulse of multiple wavelengths to spatially separate into different pulses of light each with a different wavelength from the multiple wavelengths.).
Claim(s) 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li in view of Pacala et al. (US 20190011567 A1), hereinafter Pacala.
Regarding claim 15, Li teaches the lidar system of claim 1, as described above, and further teaches:
wherein light source is configured to emit the pulses of light in a […] wavelength order, wherein:
the plurality of different wavelengths comprises W different wavelengths, wherein W is an integer greater than or equal to four (FIG. 5E shows an example of at least 5 different wavelengths.);
the emitted pulses of light comprise a plurality of pairs of emitted pulses of light, each pair of emitted pulses of light comprising first and second emitted pulses of light, the second emitted pulse of light emitted immediately after the first emitted pulse of light (This limitation is simply definitional, assigning claim language to particular aspects of a series of emitted pulses of light, as found in Li.);
the first emitted pulse of light has a wavelength of λ2 (This limitation is simply definitional, assigning claim language to particular aspects of a series of emitted pulses of light, as found in Li.);
the W different wavelengths comprise three adjacent wavelengths λ1, λ2, and λ3, wherein λ1>λ2> λ3 (This limitation is simply definitional, assigning claim language to particular aspects of a series of emitted pulses of light, as found in Li.); and
[…]
Li does not teach:
wherein light source is configured to emit the pulses of light in a non-sequential wavelength order, wherein:
[…]
the second emitted pulse of light has any of the W different wavelengths except for wavelengths λ1, λ2, and λ3.
Swanson, in the field of spectral scanning, teaches that spectral scanning provides the benefit of allowing for a flexible scanning system ([0046] “The tuning diagram of the graph 508 shows the wavelengths are stepped in time through a sequence of approximately increasing values. But many other types of tuning patterns are possible and it is not necessary that the wavelength tuning be uniformly spaced steps or even monotonic in time. Having a wavelength agile tunable laser enables great flexibility in the choice of the wavelength routing element and the dispersive emitter.”). Thus teaching the limitation:
wherein light source is configured to emit the pulses of light in a non-sequential wavelength order
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have used a non-sequential scanning pattern, as taught by Swanson, in the scanning lidar system of Li to take full advantage of the flexibility of the spectral scanning system.
The combination of Li in view of Swanson still does not explicitly teach:
the second emitted pulse of light has any of the W different wavelengths except for wavelengths λ1, λ2, and λ3.
Pacala, in the field of lidar scanning, teaches the benefits of a scanning pattern that avoids adjacent scan locations:
([0087] “While FIGS. 2B-2D illustrate an image capturing sequence in which fired emitters are advanced one column per stage, embodiments of the disclosure are not limited to any particular sequence. For example, in some embodiments the following sequence can be employed: for stage one, a first column of emitter array 210 is fired; for stage 2, column (m/2+1) is fired; for stage 3, column 2 is fired, for stage 4, column (m/2+2) is fired, etc. until the m.sup.th stage when column m is fired. Such an embodiment can be beneficial in minimizing cross-talk within the sensor array as adjacent sensor columns are not readout in successive stages.”)
While Pacala does not achieve this scanning pattern through spectral scanning, the principles as taught by Pacala, when implemented into the lidar system of Li in view of Swanson, would be achieved through the control of wavelength sequence, as that is the method of control used for scanning the light. Thus, the combination of Li in view of Swanson and further in view of Pacala, which would achieve a non-adjacent sequence by emitting pulses with non-adjacent wavelengths teaches the remaining limitation:
the second emitted pulse of light has any of the W different wavelengths except for wavelengths λ1, λ2, and λ3.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have modified the lidar system of Li in view of Swanson to minimize cross-talk between adjacent sensor elements (Pacala: [0087]).
Claim(s) 17, 19, 21 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li in view of Rezk.
Regarding claim 17, Li teaches the lidar system of claim 1, as described above, and further teaches:
wherein the receiver comprises: a […] detector array comprising a plurality of detector elements […] ([Pg. 8, Lines 3-12] “The light detector circuitry 105 includes one or more photodetectors.”),
wherein: the received pulse of light is incident on one or more detector elements of the detector array ([Pg. 8, Lines 3-12] “The light detector circuitry 105 generates incoming electrical signals that are representative of the detected incoming light.”); and
the one or more detector elements are each configured to produce a photocurrent signal corresponding to the received pulse of light ([Pg. 8, Lines 3-12] “The light detector circuitry 105 generates incoming electrical signals that are representative of the detected incoming light”); and
a pulse-detection circuit configured to determine, based on the one or more photocurrent signals, the time of arrival of the received pulse of light ([Pg. 8, Lines 3-12] “The incoming digital signals are received and processed by a control system 107… The control system 107 may determine a round trip time for the light based on its control or knowledge of the outgoing light and based on the incoming light signals.”).
Li does not teach:
wherein the receiver comprises: a one-dimensional detector array comprising a plurality of detector elements arranged along a direction corresponding to the first scan axis,
Rezk, in the same field of scanning lidar, teaches a two-dimensional scanning lidar with a one-dimensional detector array corresponding to the direction of a one-dimensional deflector ([Col. 8, Lines 4-32] “FIG. 5A illustrates a remote sensing device 500 that includes a polygon rotating mirror, according to some embodiments. In these embodiments, a scanning mechanism with a limited vertical field of view (VFOV), for example ⅙.sup.th of the desired vertical dimension of the object field to be scanned, may be used in transmit (TX) component 510… In some embodiments, the scanning mechanism may be a one-dimensional scanning mirror that scans the beam in one dimension (e.g., the vertical dimension or axis)… In some embodiments, the detector array 544 of receive (RX) component 540 may be a one-dimensional (1D) array of pixels with a FOV corresponding to the scanning mechanism.”).
While Rezk gives the example of a scanning mirror for the “scanning mechanism”, the overall arrangement presented is not concerned with the specific method of one-dimensional scanning, and thus this arrangement is easily compatible with the lidar system of Li which may involve a one-dimensional spectral scanner and a polygonal mirror. Thus, the combination of Li in view of Rezk teaches the remaining limitation, where the “first scan axis” corresponds to the scanning direction of the dispersive component 504 of Li:
wherein the receiver comprises: a one-dimensional detector array comprising a plurality of detector elements arranged along a direction corresponding to the first scan axis,
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have modified the lidar system of Li with the detection arrangement of Rezk as one of the known and predictable arrangements for lidar detectors.
Regarding claim 19, Li teaches the lidar system of claim 1, as described above, and further teaches:
wherein the received pulse of light is part of an input beam of light, the input beam comprising a plurality of received pulses of light ([Pg. 5, Line 23 - Pg. 6, Line 4] “LiDAR involves transmitting light into the environment and subsequently detecting the light returned by the environment.”; [Pg. 8, Line 13 - Pg. 9, Line 12] “In some embodiments, the light source 101 emits pulses of light”),
wherein: the input beam, prior to being directed to the receiver, is reflected by the scan mirror […] ([Pg. 7, Line 22 - Pg. 8, Line 2] “In some embodiments the beam director 104 includes bidirectional components, whereby both the outgoing light to the environment and incoming light from the environment traverse substantially the same path through the beam director 104, in opposite directions. Figure 1 represents this by the bidirectional arrow for the light traversing free space.” Note that this description entails the received light passing back through scanning component 512, which is part of the embodiment of beam director 104.); and
the receiver comprises a […] detector array comprising a plurality of detector elements […] ([Pg. 8, Lines 3-12] “The light detector circuitry 105 includes one or more photodetectors.”),
each detector element configured to detect received pulses of light […] ([Pg. 8, Lines 3-12] “The light detector circuitry 105 generates incoming electrical signals that are representative of the detected incoming light”).
Li does not teach:
wherein: the input beam, prior to being directed to the receiver, is reflected by the scan mirror and bypasses the beam deflector; and
the receiver comprises a one-dimensional detector array comprising a plurality of detector elements arranged along a direction corresponding to the first scan axis,
each detector element configured to detect received pulses of light having one particular wavelength of the plurality of different wavelengths.
Rezk, in the same field of scanning lidar, teaches a two-dimensional scanning lidar with a one-dimensional detector array corresponding to the direction of a one-dimensional deflector ([Col. 8, Lines 4-32] “FIG. 5A illustrates a remote sensing device 500 that includes a polygon rotating mirror, according to some embodiments. In these embodiments, a scanning mechanism with a limited vertical field of view (VFOV), for example ⅙.sup.th of the desired vertical dimension of the object field to be scanned, may be used in transmit (TX) component 510… In some embodiments, the scanning mechanism may be a one-dimensional scanning mirror that scans the beam in one dimension (e.g., the vertical dimension or axis)… In some embodiments, the detector array 544 of receive (RX) component 540 may be a one-dimensional (1D) array of pixels with a FOV corresponding to the scanning mechanism.”).
While Rezk gives the example of a scanning mirror for the “scanning mechanism”, the overall arrangement presented is not concerned with the specific method of one-dimensional scanning, and thus this arrangement is easily compatible with the lidar system of Li which may involve a one-dimensional spectral scanner and a polygonal mirror. Thus, the combination of Li in view of Rezk, where the “first scan axis” corresponds to the scanning direction of the dispersive component 504 of Li, teaches:
wherein: the input beam, prior to being directed to the receiver, is reflected by the scan mirror and bypasses the beam deflector (Rezk: FIG. 5E, the return beam bypasses transmit component 510, which contains the scanning mechanism. [Col. 8, Lines 4-32] “In these embodiments, a scanning mechanism… may be used in transmit (TX) component 510”); and
the receiver comprises a one-dimensional detector array comprising a plurality of detector elements arranged along a direction corresponding to the first scan axis,
each detector element configured to detect received pulses of light having one particular wavelength of the plurality of different wavelengths (A configuration in which there is one detector element per angular increment of the one-dimensional scanning mechanism is within reasonable consideration of the configuration presented by Rezk, and when combined into the system of Li, such an arrangement would correspond to each emission wavelength.).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have modified the lidar system of Li with the detection arrangement of Rezk as one of the known and predictable arrangements for lidar detectors.
Regarding claim 21, Li teaches the lidar system of claim 1, as described above, and further teaches:
wherein the received pulse of light is part of an input beam of light, the input beam comprising a plurality of received pulses of light ([Pg. 5, Line 23 - Pg. 6, Line 4] “LiDAR involves transmitting light into the environment and subsequently detecting the light returned by the environment.”; [Pg. 8, Line 13 - Pg. 9, Line 12] “In some embodiments, the light source 101 emits pulses of light”),
Li does not teach:
wherein: the input beam bypasses the scanner; and
the receiver comprises a two-dimensional detector array comprising a plurality of detector elements arranged in rows along a first direction corresponding to the first scan axis and in columns along a second direction corresponding to the second scan axis,
wherein the detector elements in each row are configured to detect received pulses of light having one particular wavelength of the plurality of different wavelengths.
Rezk, in the same field of scanning lidars, teaches:
wherein: the input beam bypasses the scanner ([Col. 4, Lines 15-37] “FIG. 1A is a block diagram illustrating components of a remote sensing device 100, according to at least some embodiments.”; FIG. 1A shows return light bypassing the transmission optics and scanning elements.); and
the receiver comprises a two-dimensional detector array comprising a plurality of detector elements arranged in rows along a first direction corresponding to the first scan axis and in columns along a second direction corresponding to the second scan axis ([Col. 4, Lines 15-37] “FIG. 1A is a block diagram illustrating components of a remote sensing device 100, according to at least some embodiments. The remote sensing device 100 may include… a receive (RX) 140 component or module… RX 140 may include, but is not limited to, an RX lens 142 and a detector array 144.”; FIGS. 1B and 1D show a two-dimensional detector array.),
Further, while the examples of FIGS. 1B and 1D show detector arrays with fewer pixels than the scanning resolution, Rezk teaches that the conventional implementation of such a system uses a detector array which matches the resolution of the beam scanning ([Col. 1, Lines 18-24] “Conventional scanning systems (e.g., LiDAR systems) are typically bulky and large in size. These conventional scanning systems typically include a large scanning mechanism and a high resolution focal plane array (FPA) with enough pixels to support the resolution of the scanning mechanism. Both angular (XY) and depth (Z) position may be determined from the detector array.”).
Thus, when the teachings of Rezk are combined into the lidar system of Li, a detector array which matches the scanning resolution, which is represented by the wavelengths of the emitted pulses, would thus have each detector element along the spectral scanning direction, be configured to receive one particular wavelength of light, thus teaching the remaining limitation:
wherein the detector elements in each row are configured to detect received pulses of light having one particular wavelength of the plurality of different wavelengths.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have modified the lidar system of Li with one of the known and conventional detection arrangements for a two-dimensionally scanning lidar, as taught by Rezk.
Claim(s) 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li in view of Rezk and further in view of Benscoter et al. (US 20230148066 A1), hereinafter Benscoter.
Regarding claim 18, Li in view of Rezk teaches the lidar system of claim 17, as described above, but does not teach:
wherein the receiver further comprises a Nxn electronic multiplexer disposed between the detector array and the pulse-detection circuit, wherein: N is a number of inputs of the multiplexer, and n is a number of outputs of the multiplexer;
the one-dimensional detector array comprises N detector elements, and each input of the multiplexer is coupled to one of the detector elements;
the pulse-detection circuit comprises n inputs, and each output of the multiplexer is coupled to one of the inputs of the pulse-detection circuit, wherein n is an integer greater than or equal to 1; and
the multiplexer is configured to couple the one or more photocurrent signals from the one or more detector elements to one or more respective inputs of the pulse-detection circuit.
Benscoter, in the field of lidar detectors, teaches:
wherein the receiver further comprises a Nxn electronic multiplexer disposed between the detector array and the pulse-detection circuit, wherein: N is a number of inputs of the multiplexer, and n is a number of outputs of the multiplexer (FIG. 27; [0294] “Multiplexer 2710 operates to read out a sensed signal from a desired pixel 1804 in accordance with a readout control signal 2708, where the readout control signal 2708 controls which of the multiplexer input lines are passed as output. Thus, by controlling the readout control signal 2708, the receiver 1400 can control which of the pixels 1804 are selected for passing its sensed signal as the return signal 1806.”);
the one-dimensional detector array comprises N detector elements, and each input of the multiplexer is coupled to one of the detector elements (FIG. 27, the Multiplexer 2710 has one input for each detector element; [0250] “The photodetector array 1802 comprises a plurality of detector pixels 1804 that sense incident light and produce a signal representative of the sensed incident light. The detector pixels 1804 can be organized in the photodetector array 1802 in any of a number of patterns… may employ a one-dimensional (1D) array of detector pixels 1804 if desired by a practitioner.”);
the pulse-detection circuit comprises n inputs, and each output of the multiplexer is coupled to one of the inputs of the pulse-detection circuit, wherein n is an integer greater than or equal to 1 (FIG. 27, Multiplexor 2710 is shown with one output.); and
the multiplexer is configured to couple the one or more photocurrent signals from the one or more detector elements to one or more respective inputs of the pulse-detection circuit ( [0294] “Multiplexer 2710 operates to read out a sensed signal from a desired pixel 1804 in accordance with a readout control signal 2708, where the readout control signal 2708 controls which of the multiplexer input lines are passed as output. Thus, by controlling the readout control signal 2708, the receiver 1400 can control which of the pixels 1804 are selected for passing its sensed signal as the return signal 1806.”).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have modified the lidar system of Li in view of Rezk with the multiplexer of Benscoter to improve signal to noise ratio by isolating the return signal from specific detector elements.
Claim(s) 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li in view of Rezk and further in view of Jones et al. (US 20110303848 A1), hereinafter Jones.
Regarding claim 20, Li in view of Rezk teaches the lidar system of claim 19, as described above, but does not teach:
wherein the detector array further comprises a variable optical filter configured to transmit particular wavelengths of light to the detector elements, wherein the particular transmitted wavelengths vary with position along the detector array.
Jones, in the field of spectral detection, teaches that linear variable filters may be used in combination with multiple detectors for spectral imaging, including in combination with other diffraction methods ([0128] “The same approaches to wavelength selection can also be employed if the wavelength selection is placed on the detection side of the fibrous web 70 as mentioned above. For example, multiple detectors combined with wavelength selection devices, such as an array of filters, a linear variable filter, a prism, a diffraction grating or combination thereof, may be employed.”). Thus, Li in view of Rezk, further combined with the teachings of Jones may incorporate a linear variable filter onto the multiple detector elements, thus teaching:
wherein the detector array further comprises a variable optical filter configured to transmit particular wavelengths of light to the detector elements, wherein the particular transmitted wavelengths vary with position along the detector array.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have modified the lidar system of Li in view of Rezk with a linear variable filter, as taught by Jones, to ensure fine-tuned spectral detection.
Claim(s) 22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li in view of Campbell et al. (US 20180284279 A1), hereinafter Campbell.
Regarding claim 22, Li teaches the lidar system of claim 1, as described above, and further teaches:
wherein the receiver comprises: a detector configured to produce a photocurrent signal corresponding to the received pulse of light ([Pg. 8, Lines 3-12] “The light detector circuitry 105 includes one or more photodetectors… The light detector circuitry 105 generates incoming electrical signals that are representative of the detected incoming light”);
Li does not explicitly teach:
an electronic amplifier configured to amplify the photocurrent signal to produce a voltage signal that corresponds to the photocurrent signal; and
a plurality of comparators coupled to a respective plurality of time-to-digital converters (TDCs),
wherein: each comparator is configured to provide an electrical-edge signal to a corresponding TDC when the voltage signal rises above or falls below a particular threshold voltage; and
the corresponding TDC is configured to produce a time value corresponding to a time when the electrical-edge signal was received,
wherein the time of arrival of the received pulse of light is determined based on one or more time values produced by one or more of the TDCs.
Campbell, in the same field of lidar systems, teaches:
an electronic amplifier configured to amplify the photocurrent signal to produce a voltage signal that corresponds to the photocurrent signal ([0130] “FIG. 13 illustrates the detector 602”; [0131] “More particularly, the amplifiers 609 amplify the light detection signals from the light detector 602 and provide an amplified signal to a comparator 610. While the circuitry of FIG. 13 is illustrated as including a separate amplifier 609 disposed in each of the parallel connected amplitude detection circuits 608, one or more amplifiers (e.g., a TIA 510 and/or a gain circuit 512) could be configured to amplify the light detection signals from the detector 602 prior to the light detection signals being split and provided to the separate amplitude detection circuits 608.”); and
a plurality of comparators coupled to a respective plurality of time-to-digital converters (TDCs) ([0130] “Each of the parallel connected amplitude detection circuits 608 is illustrated as including… a comparator 610 and a time-to-digital converter (TDC) 612”),
wherein: each comparator is configured to provide an electrical-edge signal to a corresponding TDC when the voltage signal rises above or falls below a particular threshold voltage ([0131-0132] “comparator 610 which compares the amplified light detection signal to a particular threshold value and outputs a positive or other signal indicating when the comparison criteria is met… the output signal of each comparator 610… is provided to an associated TDC 612.”); and
the corresponding TDC is configured to produce a time value corresponding to a time when the electrical-edge signal was received ([0133] “the TDCs 612 clock, store, and/or output the value or values of the associated timer when the TDC 612 receives an appropriate (e.g., positive) input from the associated comparator 610.”),
wherein the time of arrival of the received pulse of light is determined based on one or more time values produced by one or more of the TDCs ([0136] “the envelope detector 614 receives the outputs of the TDCs 612 and analyzes these signals”; [0138] “Of course, the envelope detector 614… may provide some or all of this information to the range detector circuit 616 of FIG. 13… Such a range detector circuit 616 may, for example, use the detection time associated with the rising edge, the falling edge, the peak, the center, or some other point on the detected pulse.”).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have modified the lidar system of Li with the detection circuitry of Campbell to compensate for “range walk” (Campbell: [0139]).
Claim(s) 26 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li in view of Official Notice and Izatt et al. (US 20210333396 A1), hereinafter Izatt.
Regarding claim 26, Li teaches the lidar system of claim 25, as described above, and further teaches:
wherein: the polygon mirror comprises S reflective surfaces, wherein S is an integer greater than or equal to 2 (FIG. 7A shows a polygon mirror with five sides.);
the polygon mirror is configured to rotate at a rotation speed of R revolutions per second ([Pg. 20, Lines 6-12] “The polygon mirror may rotate continuously.”);
the portion of the emitted pulses of light reflected from each of the reflective surfaces of the polygon mirror are associated with a single scan across at least a portion of the field of regard of the lidar system (This limitation describes the basic functional outcome of a polygon mirror which rotates continuously in one direction.); and
Li does not explicitly teach:
the lidar system is configured to produce point clouds at a frame rate of F frames per second according to an expression F=SxR.
However, this limitation describes the basic functional outcome of a scan using a polygon mirror in which all the mirror facets have the same tilt angle with respect to the rotational axis of the polygon mirror, and where the scan axis associated with the polygon mirror is the “slow axis”.
While Li is silent as to the tilt of angle of the mirror facets of the polygon mirror, the examiner takes official notice of the fact that polygon mirrors in which all of the mirror facets have the same tilt angle with respect to the rotational axis are well-known and conventional in the art.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have used such a conventional polygon mirror in the lidar system of Li.
Li is also silent as to whether the scan repetition rate of the spectral axis or the scan repetition rate of the mechanical axis is faster.
Izatt, in the field of spectrally encoded scanning, teaches the speed-potential of spectral scanning, and thus using spectral scanning for the “fast-axis” ([0043] “A 3D sensing depth camera involves a time-frequency multiplexed frequency-modulated continuous wave (FMCW) light detection and ranging (LiDAR) technique for high-speed high-precision 3D imaging using a swept source, a diffractive optical element for fast-axis beam steering…”; [0053] “FIG. 3B illustrates a set of scanning beams at different frequencies along the second axis for a particular setting on the first axis. As can be seen, a sample beam is distributed for spectral encoding in the second axis direction. Each beam corresponds to each frequency of the frequency sweep of the light source. This spectrally encoded scan repeats as the scanner scans in the first axis direction.”). While Izatt teaches this scanning arrangement in the context of FMCW lidar, the basic principle of the fast-scanning potential of spectral scanning would hold for any scanning system.
Thus, the lidar system of Li, in combination with a conventional polygon mirror, in which all of the mirror facets have the same tilt angle with respect to the rotational axis of the polygon mirror, and in combination with the teaching of Izatt to use spectral scanning as the “fast-axis”, teaches the remaining limitation:
the lidar system is configured to produce point clouds at a frame rate of F frames per second according to an expression F=SxR.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have chosen to scan the spectrally scanned axis of the lidar system of Li faster than the mechanically scanned axis, as taught by Izatt, since this allows for overall high-speed scanning (Izatt: [0043] “A 3D sensing depth camera involves a time-frequency multiplexed frequency-modulated continuous wave (FMCW) light detection and ranging (LiDAR) technique for high-speed high-precision 3D imaging using a swept source, a diffractive optical element for fast-axis beam steering…”).
Claim(s) 27 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li in view of Izatt.
Regarding claim 27, Li teaches the lidar system of claim 1, as described above, and further teaches:
That the scan mirror may be a mirror which rotates back and forth ([Pg. 20, Lines 6-12] “In another example, the scanning component 512 is a rotating reflector, for example a mirror that rotates discontinuously, by cycling through rotation in one direction and then in the reverse direction and so forth.”).
Li is silent as to the specific form of scan mirror, and thus does not explicitly teach:
wherein the scan mirror comprises a galvanometer scanner.
Izatt, in the field of spectrally scanned lidar, teaches:
wherein the scan mirror comprises a galvanometer scanner ([0052] “FIG. 3A illustrates an example sample arm with beam shaping optics for a system for 3D depth sensing; and FIG. 3B illustrates scanning operation… Referring to FIG. 3A, a sample arm 300 can include… a scanner 320 for beam scanning in a first axis (e.g., vertical axis)… and a diffractive optical element 340 for spectrally encoded scanning along a second axis (e.g., horizontal axis). The sample arm 300 can receive the sample beam from a beam splitter system (e.g., as described with respect to sample arm 130 of FIG. 1), collimates the sample beam via the collimator 310, which directs the sample beam to the scanner 320, which can be a galvanometer mirror.”).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have used a galvanometer scanner, as taught by Izatt, in the lidar system of Li as one of the well-known and predictable choices for a rotating mirror.
Claim(s) 29 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li in view of Official Notice.
Regarding clam 29, Li teaches the lidar system of claim 1, as described above, and further teaches:
wherein: the time of arrival of the received pulse of light corresponds to a round-trip time (T) for the portion of the one of the emitted pulses of light to travel to the target and back to the lidar system ([Pg. 8, Lines 3-12] “The control system 107 may determine a round trip time for the light based on its control or knowledge of the outgoing light and based on the incoming light signals.”); and
the distance (D) to the target is determined […] ([Pg. 5, Line 23 - Pg. 6, Line 4] “LiDAR involves transmitting light into the environment and subsequently detecting the light returned by the environment. By determining the time it takes for the light to make a round trip to and from, and hence the distance of, reflecting surfaces within a field of view (FOV), an estimation of the spatial profile of the environment may be formed.”).
Li does not explicitly teach:
the distance (D) to the target is determined from an expression D= cT/2, wherein c is a speed of light
While Li is silent as to the specific method by which distance is calculated from the round trip time, the examiner takes Official Notice of the fact that the equation D=cT/2 is the conventional and well-known equation for time-of-flight lidar, which is derived from the naturally understood propagation of light.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have used the well-known equation D=cT/2 in the lidar system of Li for the calculation of distance based on a round-trip time.
Claim(s) 30 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li in view of Derickson et al. (Derickson, Dennis, et al. "SGDBR single-chip wavelength tunable lasers for swept source OCT." Coherence Domain Optical Methods and Optical Coherence Tomography in Biomedicine XII. Vol. 6847. SPIE, 2008.), hereinafter Derickson.
Regarding clam 30, Li teaches the lidar system of claim 1, as described above, but does not explicitly teach:
wherein the plurality of different wavelengths are between 1400 nanometers (nm) and 1600 nm.
Derickson, in the field of SG-DBR lasers, teaches a tunable-wavelength SG-DBR laser with a wavelength range from 1525 to 1565 ([abs] “Sampled Grating Distributed Bragg Reflector (SGDBR) monolithic tunable lasers are now entering the production phase in telecommunications applications. These tunable lasers are unique in that they offer wide wavelength tuning (1525 to 1565 nm), fast wavelength tuning (5 ns) and high speed amplitude modulation all on the same monolithic chip.”).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have used the SG-DBR laser of Derickson in the lidar system of Li, as one choice for SG-DBR laser with predictable result.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
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Claims 1-3 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claim 29 of copending Application No. 18093041 (reference application) (US20230213628). Although the claims at issue are not identical, they are not patentably distinct from each other because claim 29 anticipates the limitations of the instant claims, as shown below (instant claims are outline in italics, with the limitations of claim 29 of the reference application in plain text):
Regarding claim 1:
A lidar system comprising:
A lidar system comprising:
a wavelength-tunable light source configured to emit pulses of light, each emitted pulse of light having a particular wavelength of a plurality of different wavelengths; a
a light source configured to emit pulses of light;
wherein the seed laser diode is a sampled-grating distributed Bragg reflector (SG-DBR) laser configured to produce the seed light at a plurality of different wavelengths,
wherein each of the emitted pulses of light has a particular wavelength of the plurality of different wavelengths.
scanner configured to scan the emitted pulses of light across a field of regard of the lidar system, the scanner comprising:
a scanner configured to scan the emitted pulses of light across a field of regard of the lidar system, the scanner comprising:
a beam deflector configured to angularly deflect each emitted pulse of light along a first scan axis according to the particular wavelength of the emitted pulse of light; and
a beam deflector configured to direct each emitted pulse of light along a first scan axis; and
wherein the beam deflector is configured to direct each emitted pulse of light along the first scan axis by angularly deflecting each emitted pulse of light along the first scan axis according to the particular wavelength of the emitted pulse of light.
a scan mirror configured to scan the emitted pulses of light along a second scan axis different from the first scan axis;
a scan mirror configured to scan the emitted pulses of light along a second scan axis different from the first scan axis;
a receiver configured to:
a receiver comprising a one-dimensional detector array comprising a plurality of detector elements arranged along a direction corresponding to the first scan axis, wherein the receiver is configured to:
detect a received pulse of light, the received pulse of light comprising a portion of one of the emitted pulses of light scattered by a target located a distance from the lidar system; and
detect a received pulse of light, the received pulse of light comprising a portion of one of the emitted pulses of light scattered by a target located a distance from the lidar system; and
determine a time of arrival of the received pulse of light; and
determine a time of arrival of the received pulse of light; and
a processor configured to determine the distance from the lidar system to the target based on the time of arrival of the received pulse of light.
a processor configured to determine the distance from the lidar system to the target based on the time of arrival of the received pulse of light.
Regarding claim 2:
wherein the light source comprises: a wavelength-tunable seed laser diode configured to produce seed light at the plurality of different wavelengths; and
wherein the seed laser diode is a sampled-grating distributed Bragg reflector (SG-DBR) laser configured to produce the seed light at a plurality of different wavelengths,
wherein each of the emitted pulses of light has a particular wavelength of the plurality of different wavelengths.
an optical amplifier configured to amplify the seed light to produce the emitted pulses of light,
an optical amplifier configured to amplify the seed light to produce the emitted pulses of light,
wherein the optical amplifier comprises a semiconductor optical amplifier (SOA), a fiber- optic amplifier, or a SOA followed by a fiber-optic amplifier.
wherein the optical amplifier comprises a semiconductor optical amplifier (SOA), a fiber- optic amplifier, or a SOA followed by a fiber-optic amplifier.
Regarding claim 3:
wherein the wavelength-tunable seed laser diode comprises a distributed Bragg reflector (DBR) laser configured to produce the seed light at the plurality of different wavelengths.
wherein the seed laser diode is a sampled-grating distributed Bragg reflector (SG-DBR) laser configured to produce the seed light at a plurality of different wavelengths,
This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented.
Conclusion
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/SEAN C. GRANT/Examiner, Art Unit 3645
/YUQING XIAO/Supervisory Patent Examiner, Art Unit 3645