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 .
This is the first office action on the merits and is responsive to the papers filed 06/07/2023. Claims 1-16 are currently pending and examined below.
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.
Claims 1-16 are rejected under 35 U.S.C. 103 as being unpatentable over Justus et al. (US 5491579 A, “Justus”) in view of Huang et al. (US 20210116543 A1, “Huang”).
Regarding claim 1, Justus teaches A (n) (LIDAR) optical receiver system, comprising:
an optic to receive an optical signal (The focusing lens 23 receives the incident beam and focuses it (FIG. 1 / FIG. 2A–2B; Col 4: lines 47-50, col 6: lines 4-8: incident beam… focusing lens 23… focuses… to a focal point 24).);
an optical filter to control an output from the optic (The protective element/sample cell 25 is the limiter element that controls what continues toward the sensor: Low intensity: passes through … without being defocused (FIG. 1, col 4: line 52 to col 5: line 4. See also, FIG. 2A and FIG. 2B, Col 5: line 61-col 6: line 3); High intensity: “defocuses … strongly aberrated rings … blocked” (FIG. 2A and FIG. 2B, col 6: lines 4-17). Justus (Col 4: lines 47-51) calls it “protective element,” “optical limiter,” “sample cell,” not “filter,” but functionally it limits transmission as intensity increases, which reads on “optical filter to control an output.”); and
an optical sensor to receive an output from the optical filter (The sensor/eye 35 receives the transmitted light after the limiter/aperture/lens (FIG. 1, signal probe 33, Col 5: lines 23-32. See also, FIG. 2A–2B, Col 5: line 61-col 6: line 3, col 6: lines 4-17; passes… through collecting aperture 27 and imaging lens 29 to the sensor or eye 35).).
Justus fails to explicitly teach a LIDAR optical receiver system. However, Hung teaches a Lidar receiver with a mode selective detection unit (Para 62, 67; FIGS. 1-2).
It would have been obvious to one of ordinary skill in the art at the time of the invention to incorporate the optical limiting device of Justus into the optical receiver path of the LiDAR system of Hang in order to protect the LiDAR detector from excessive optical power, such as high-intensity reflections or external laser interference, because optical limiters are well-known protective components used to prevent damage or saturation of optical detectors.
Regarding claim 2, Justus, in view of Huang, teaches the system according to claim 1, wherein the optic comprises a lens (Justus, focusing lens 23, FIG. 1/2A/2B, Col 4: lines 47-51) and the optical filter comprises a non-linear optical (NLO) element to receive an output from the lens (Justus, The protective element 25 is disposed at the focus and receives the converged beam (FIG. 1, Col 4: lines 47-51: focuses… to a focal point 24 inside… protective element 25. Justus explicitly frames the limiter as using nonlinear optical materials whose index of refraction or absorption coefficient are dependent on intensity (Justus, Col 2: lines 46-49; col 4: line 52 to col 5: line 4)),
wherein the NLO element has an intensity dependent optical index (in operation: At high intensity “defocuses… aberrated rings…” (Justus, FIG. 2B, Col 6: lines 4-17), which is consistent with intensity-dependent refractive index behavior. See also, Col 6: lines 31-46).
Regarding claim 3, Justus, in view of Huang, teaches system according to claim 2, further including an aperture between the NLO element and the optical sensor (Justus, Light from the sample cell 25 passes through a 10 mm collecting aperture 27 … and … imaging lens 29 … onto… sensor/eye 35. (FIG. 1 Col 5: lines 5-13; also FIG. 2A/2B, col 5: lines 47-60).
Regarding claim 4, Justus, in view of Huang, teaches the system according to claim 3, wherein the NLO element is configured to attenuate the output from lens when the output from the lens is above an optical damage threshold (Justus, The protective element/sample cell 25 is the limiter element that controls what continues toward the sensor: Low intensity: passes through … without being defocused (Justus, FIG. 2A and FIG. 2B, Col 5: line 61-col 6: line 3); High intensity: “defocuses … strongly aberrated rings … blocked” (FIG. 2A and FIG. 2B, col 6: lines 4-17).
Regarding claim 5, Justus, in view of Huang, teaches the system according to claim 4, wherein the NLO element is configured to attenuate the output from the lens by increasing divergence (Justus describes “defocuses the high fluence… strongly aberrated… rings… blocked” (FIG. 2B / FIG. 3A–3B). Defocus/aberration implies increased divergence/angle spread such that the collecting aperture truncates it.).
Regarding claim 6, Justus, in view of Huang, teaches the system according to claim 4, further including an optical pump coupled to the NLO element to bias the optical damage threshold (Hang teaches pump pulses interacting with a nonlinear optical module (Justus, Para 8, a pulse generation unit configured to create probe signals and trigger a driving pump; FIG. 2 Para 62).).
It would have been obvious to one of ordinary skill in the art to modify the nonlinear optical limiter of Justus to include an optical pump coupled to the nonlinear optical element, as taught by Huang, in order to control or bias the nonlinear optical response threshold of the limiter and thereby enable improved control of when attenuation occurs.
Such modification would have predictably allowed the limiter to adjust or tune the optical damage threshold, which is beneficial in optical sensing systems such as LiDAR receivers where incident optical power may vary significantly.
Regarding claim 7, Justus, in view of Huang, teaches the system according to claim 2, wherein the NLO element is configured to attenuate the output from the lens when the output from the lens is above an optical damage threshold (Justus, In combination with the rejection of claim 4. High fluence → defocus → aperture blocks → only small attenuated portion reaches sensor/eye (FIG. 2B).).
Regarding claim 8, Justus, in view of Huang, teaches the system according to claim 7, wherein the NLO element is configured to attenuate by increasing absorption (Justus (claims 2, 6, 12, 15; FIG. 2A and FIG. 2B, col 6: lines 4-17 ) discloses the protective element as: a solution of absorbing material dissolved in a solvent… possessing refractive thermal nonlinearities; absorber… absorbs electromagnetic energy and transforms that energy into thermal energy; nigrosin acts to absorb light…transfer heat to solvent. So, Justus provides a clear attenuate via absorption/absorber mechanism (even though the overall limiting effect is often expressed as defocusing + aperture truncation, the absorption is explicitly present and increases heating/limiting).
Regarding claim 9, Justus, in view of Huang, teaches the system according to claim 7, wherein the NLO element is configured as a reverse-saturable absorber (via a two-photon absorption) above a critical optical irradiance at an input optical-frequency (Justus discloses reverse saturable absorber (RSA) enhancement (Justus, FIG. 6, Col 3: line 66 to col 4: line 3): “thermal/RSA limiter… absorption… increases at higher intensities… RSA material such as C60.”).
Justus, in view of Huang, fails to explicitly wherein the NLO element is configured as a reverse-saturable absorber via a two-photon absorption.
However, Huang teaches nonlinear optical modules in which an optical signal and a pump interact through nonlinear optical processes within an NLO medium (Para 10, 62). It would have been obvious to implement the nonlinear optical limiter of Justus using nonlinear absorption mechanisms such as two-photon absorption above a critical optical irradiance, as such nonlinear optical effects are well-known mechanisms for intensity-dependent attenuation in nonlinear optical materials.
Regarding claim 10, Justus, in view of Huang, teaches the system according to claim 8, further including an optical pump coupled to the NLO element to bias the optical damage threshold (Hang teaches pump pulses interacting with a nonlinear optical module (Huang, Para 8, a pulse generation unit configured to create probe signals and trigger a driving pump; FIG. 2 Para 62).).
It would have been obvious to one of ordinary skill in the art to modify the nonlinear optical limiter of Justus to include an optical pump coupled to the nonlinear optical element, as taught by Huang, in order to control or bias the nonlinear optical response threshold of the limiter and thereby enable improved control of when attenuation occurs.
Such modification would have predictably allowed the limiter to adjust or tune the optical damage threshold, which is beneficial in optical sensing systems such as LiDAR receivers where incident optical power may vary significantly.
Regarding claim 11, Justus, in view of Huang, teaches the system according to claim 1, wherein the optic comprises a lens to receive an optical signal and, the optical filter comprises a non-linear optical (NLO) element to receive an output from the lens, wherein the NLO element has an intensity dependent optical index (Justus, see rejection of claims 2), and further including:
a photodetector coupled to the NLO element (Justus, Fig. 1, col 5: lines 23-32; Justus discloses a detector configured to convert transmitted optical radiation into an electrical signal (signal probe 33). A device that converts optical radiation into an electrical signal is necessarily a photodetector, such as a photodiode or photomultiplier, as understood by those of ordinary skill in optical instrumentation.).
an optical source (Justus, FIGS. 1/2A/2B. 2, incident beam comes from an optical source) to transmit an optical signal through the NLO element to the photodetector (Justus shows in FIGS. 1/2A/2B, the sensor/signal probe is coupled to the protective element 25);
and a controller (Huang, Fig. 1, control and processing unit) coupled to an output of the photodetector and to the sensor, wherein the controller is configured to control the sensor based on the output of the photodiode (Huang, para 17, 58. It would have been obvious to one of ordinary skill in the art to incorporate the control architecture of Huang into the optical receiver protection system of Justus in order to control operation of the sensing system based on detected signal levels.
Such modification would allow the system to dynamically manage the sensor or receiver operation based on detected optical intensity, improving protection and operational control in optical sensing systems such as LiDAR receivers where signal intensity may vary significantly.).
Regarding claim 12, Justus, in view of Huang, teaches the system according to claim 11, wherein the controller is configured to deactivate the sensor based on the output of the photodiode (As discussed with respect to claim 11, Huang teaches a control and processing unit configured to control operation of the detection system (Para 17, 58). It would have been obvious to configure the controller to deactivate the sensor based on the photodiode output when excessive optical intensity is detected, consistent with the sensor protection function of the optical limiter system of Justus.).
Regarding claim 13, Justus, in view of Huang, teaches the system according to claim 1, wherein the optic comprises a collimator to receive an incoming optical pulse (Justus, focusing lens 23, FIG. 1/2A/2B, Col 4: lines 47-51. See also, the rejection of claim 2).
Huang, teaches the optical filter comprises a non-linear optical fiber to receive a signal from the collimator, and further including: a passband filter to filter an output from the optical fiber; a sensor to receive an output from the passband filter; and a laser pump coupled to the optical fiber.
Huang teaches a LiDAR receiver architecture in which received backscattered optical signals are processed by a nonlinear optical detection module prior to detection. The reference discloses that the nonlinear optical module receives the signal together with a pump to produce nonlinear spectral conversion of the signal (Para 62-63) and that the detection architecture may be implemented using fiber-based optical components (Para 7,70). The nonlinear module is followed by a spectral filtering module and a photodetector (Para 64-65).
It would have been obvious to modify the nonlinear optical element of Justus to implement the nonlinear filtering stage using fiber-based nonlinear optical components as taught by Huang in order to process received optical signals using nonlinear optical interactions prior to detection in a LiDAR receiver system.
Regarding the limitation wherein the fiber is configured to output a supercontinuum of coherent optical frequencies if the signal from the collimator is above a threshold. As described in paragraphs 62-63 (Huang), the nonlinear optical module receives both the optical signal and a driving pump and performs nonlinear optical interaction within the nonlinear medium, generating output light at new optical frequencies (e.g., sum or difference frequencies). The generation of additional coherent optical frequencies through nonlinear interaction corresponds to the claimed production of multiple optical frequency (supercontinuum) components from the nonlinear optical element. The claim does not require any specific nonlinear mechanism for producing the plurality of optical frequencies, only that the nonlinear optical element outputs multiple coherent optical frequency components, which is satisfied by the nonlinear frequency conversion process described in paragraphs 62-63.
Regarding claim 14, Justus, in view of Huang, teaches the system according to claim 1, wherein the optic comprises a collimator to receive an incoming optical pulse (Justus, focusing lens 23, FIG. 1/2A/2B, Col 4: lines 47-51. See also, the rejection of claim 2). Huang, teaches the optical filter comprises a non-linear optical fiber to receive a signal from the collimator, and further including: a passband filter to filter an output from the optical fiber; a sensor to receive an output from the passband filter; and a laser pump coupled to the optical fiber.
Huang teaches the optical filter comprises a non-linear optical fiber to receive an output from the collimator (Para 7, the optical system is integrated in free-space or fibers or photonic integrated circuits; Para 70, or the all-in-fiber configuration, the detection module may be realized using fiber-optic components. See also the rejection of claim 13),
wherein the fiber includes a core and shell configuration (All optical fibers include: core, cladding (shell) so it is obvious that the optical fiber in Huang will include core, cladding (shell).) and is configured to absorb energy from the output from the collimator if a peak intensity of the output from the collimator is above a threshold (Justus Sample cell 25 acts as a nonlinear optical limiter. Justus explains that the nonlinear medium attenuates optical energy when the incident intensity exceeds a threshold, protecting the sensor. See the rejection of claim 4), and further including: a laser pump coupled to the optical fiber (Huang, Para 63, The NLO module takes the received signal and the driving pump as two inputs.).
It would have been obvious to implement the nonlinear optical element of Justus using fiber-based nonlinear optical components as taught by Huang because the reference explicitly discloses that the nonlinear detection module may be implemented using fiber-based optical components, enabling integration of nonlinear optical signal processing within LiDAR receiver systems.
It would have been further obvious to one of ordinary skill in the art to modify the nonlinear optical limiter of Justus to include an optical pump coupled to the nonlinear optical element, as taught by Huang, in order to control or bias the nonlinear optical response threshold of the limiter and thereby enable improved control of when attenuation occurs.
Such modification would have predictably allowed the limiter to adjust or tune the optical damage threshold, which is beneficial in optical sensing systems such as LiDAR receivers where incident optical power may vary significantly.
Regarding claim 15, Justus, in view of Huang, teaches the system according to claim 1, wherein the optic comprises a collection optic to receive an optical input signal (Justus, focusing lens 23, FIG. 1/2A/2B, Col 4: lines 47-51. See also, the rejection of claim 2).
Huang teaches the optical filter comprises a splitter to split an output from the collection optic into first and second signals in a ratio of n:m (Para 62, The detection module receives multiple optical components including signal, pump, and converted signals and routes them through filtering and detection stages. Optical systems routinely use optical splitting or routing elements to distribute signals into different processing paths. The splitting (ratio) can be 50/50, 90/10, 70/30),
and further including: a photodetector to receive the first signal (Huang, para 65, a silicon avalanche photodiode (Si-APD) detects the signals.);
a delay module to receive the second signal (Huang, Para 60, the timing unit may be realized by implementing an optical delay line);
a controller coupled to the photodetector (Huang, Para 17, 58, a control and processing unit controls the operation of the system.); and
a sensor to receive an output from the delay module (Justus, FIGS.1/2A-2B; Sensor 33/35 receives the optical signal transmitted through the system.).
It would have been obvious to divide the received optical signal into multiple processing paths using an optical splitter so that one portion of the signal may be directed to a photodetector while another portion is routed through a delay module for timing alignment and processing, since optical signal splitting for parallel signal processing is a well-known technique in LiDAR and optical sensing systems.
Regarding claim 16, Justus, in view of Huang, teaches the system according to claim 15, further including a switch coupled to the controller, wherein the switch is coupled between the sensor and the delay module (Huang (Para 60) teaches implementing the timing unit using optical delay modules and combining delay modules for coarse and fine delay control. Selection of different delay paths requires routing of the optical signal between delay modules prior to reaching the sensor. Such routing is performed using switching elements that direct the delayed optical signal to the sensor. The reference further discloses a control and processing unit controlling system operation (Para 58). Therefore, the system includes a switch controlled by the controller between the delay module and the sensor.).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Soileau et al. (US 4846561 A), teaches Monolithic Optical Power Limiter Based on Two-photon Absorption
Watanabe et al. (US 20100221014 A1), teaches optical fiber transmission system and method
Ariel Lipson (US 20170350982 A1), teaches Multi-wavelength array lidar
Fujii et al. (US 20190162596 A1), teaches Imaging device provided with light source that emits pulsed light and image sensor
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/JEMPSON NOEL/Examiner, Art Unit 3645
/YUQING XIAO/Supervisory Patent Examiner, Art Unit 3645