The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
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 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.
DETAILED ACTION
Claim Rejections - 35 USC § 102
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)(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 26 is rejected under 35 U.S.C. 102(a)(2) as being anticipated by Adams et al (US 6,122,421 A).
Regarding claim 26, Adams discloses (Figs. 6 – 10; 7:15 – 8:42) an optical device comprising:
a waveguide (optical fiber) 11; and
a Bragg grating 10a defined in at least a portion of the waveguide 11 (claim 3),
wherein the Bragg grating 10a is configured to interact with light propagating in the waveguide 11 so as to compensate dispersion (“dispersion compensating fiber gratings (10a, 10b, 10c, 10d, . . . 10n)” at 7:26 – 28) of the light by transmitting the light in a regime close to a stopband of the Bragg grating 10a (“an alternative arrangement is to use the grating in the transmission mode rather than the reflective mode. In this case, preferably the grating is unchirped and apodized, and the dispersion exists close to the edge of the stop band where the transmission is high. Thus, dispersion is provided for the pass channel rather than for the reflected channel and a circulator may be avoided” at 8:45 – 51, emphasis added).
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 of this title, 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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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.
Claims 1 – 5, 9, 11, 13 – 15, 17, 18, and 23 – 27 are rejected under 35 U.S.C. 103 as being unpatentable over Tan et al (US 2016/0139489 A1) in view of Adams.
Regarding claim 1, Tan discloses (Figs. 1, 2, 4, and 7; Abstract; para. 0034, 0042 – 0125, 0145, and 0146) an optical device for dispersion compensation comprising (with reference to Figs. 1A and 1B):
a channel waveguide 102 and two sidewalls (parallel to the direction of light 106) coupled to at least a portion of the channel waveguide 102 (para. 0044 – 0051), the two sidewalls respectively arranged at opposing sides of the channel waveguide 102 (as seen in Figs. 1A and 1B) along a longitudinal axis (vertical axis in Figs. 1A and 1B) of the channel waveguide 102,
wherein each of the two sidewalls comprises a plurality of optical elements 104a/104b arranged along the channel waveguide 102 of the waveguide, and the plurality of optical elements 104a/104b are configured to interact with light 106 propagating in the waveguide 102 so as to compensate dispersion of the light 106 (para. 0034, 0040 – 0042, and 0050 – 0053).
Tan shows (e.g., Fig. 7A) that a stopband (almost complete (100%) reflection at wavelengths shorter than about 1.556 mm) of the plurality of optical elements 104a/104b defined by a period L of the plurality of optical elements 104a/104b: the 3 curves in Fig. 7A show that the change of period L from 4 nm (curve 742) to 7 nm (curve 744) and to 10 nm (curve 746) results in a shift of the stopband edge to shorter wavelengths. Tan also discloses both reflective-type embodiments (Figs. 3A and 3C) and transmissive-type embodiments (inset in Fig. 4; Figs. 7A and 7B), considers (Fig. 7B) wavelengths slightly longer than the stopband edge (i.e., in the transmission regime), and shows that the plurality of optical elements 104a/104b can provide a group delay (dispersion) compensation close to the stopband edge (corresponding to at the left end of the curves 752,754,756).
Hence, Tan generally renders obvious that the plurality of optical elements 104a/104b (they form a grating; para. 0025, 0122, and 0145) can be configured to interact with light 106 propagating in the waveguide 106 so as to compensate dispersion of the light by transmitting the light 106 in a regime close to a stopband of the plurality of optical elements 104a/104b defined by the period L of the plurality of optical elements 104a/104b. Furthermore, Adams discloses (Figs. 1 and 9; Abstract; 8:22 – 62) a dispersion-compensating grating 12 (detailed in Fig. 1) and expressly states that “an alternative arrangement is to use the grating in the transmission mode rather than the reflective mode. In this case, preferably the grating is unchirped and apodized, and the dispersion exists close to the edge of the stop band where the transmission is high. Thus, dispersion is provided for the pass channel rather than for the reflected channel and a circulator may be avoided” (8:45 – 51, emphasis added).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention that the channel waveguide with a dispersion-compensating grating, as taught by Tan, can be configured to interact with light 106 propagating in the waveguide 106 so as to compensate dispersion of the light by transmitting the light 106 in a regime close to a stopband of the plurality of optical elements 104a/104b defined by the period L of the plurality of optical elements 104a/104b, as generally rendered obvious by Tan and expressly stated/taught by Adams. Operating the dispersion-compensating device in a regime close to a stopband maximizes dispersion compensating ability while still maintaining high transmission (low optical transmission loss). Furthermore, a need for a circulator may be avoided (ibid).
In light of the foregoing analysis, the Tan – Adams combination teaches expressly or renders obvious all of the recited limitations.
Regarding claim 2, Tan illustrates (inset of Fig. 4 and Fig. 5B) a well-known fact that a stopband may have two edges, one (left) edge on the shorter-wavelength side (red side) and the other (right) edge on the longer-wavelength side (blue side). The two edges may have different/opposite slopes of dispersion (normal and anomalous dispersion) (“In various embodiments, the plurality of optical elements 104a, 104b, 104c may generate different or varying signs (e.g., positive or negative) and/or different or varying magnitudes of each of the second order dispersion and the third order dispersion. For example, the plurality of optical elements 104a, 104b, 104c may generate or be characterized by normal dispersion or anomalous dispersion, as well as positive dispersion slope or negative dispersion slope. This may be helpful in compensating for the inherent dispersive properties of the channel waveguide 102” at para. 0053). Note that Figs. 2A and 2B shows inputs and outputs for light with opposite signs (positive and negative) dispersion. Hence, the Tan – Adams combination renders obvious that the plurality of optical elements 104 can be configured to interact with the light 106 propagating in the channel waveguide 102 so as to compensate positive dispersion of the light by transmitting the light in a regime close to a red-side (shorter-wavelength side) of the stopband of the plurality of optical elements where the transmission causes negative dispersion.
Regarding claim 3, Tan teaches that the plurality of optical elements 104a can have a sinusoidal profile (“the corrugations 104a may have a sinusoidal profile. In other words, the channel waveguide 102 may include sinusoidally modulated sidewalls. This may mean that the optical device 100a of various embodiments may include a sinusoidally corrugated waveguide grating” at para. 0059).
Regarding claim 4, Tan teaches that the sidewalls can be apodized (para. 0112 and 0125 – 0128) in a manner that an amplitude DW/2 (as denoted in Fig. 1A) gradually increases from the two ends to a center portion of the sidewalls, for example, as expressed by 1 – f(z), wherein f(z) is a Blackman function in Eq (9) and have zero values at z = 0 and z = L (grating length) and a value of 1 at z = L/2 (note: the expression in Eq (9) has a typographical error in the first cosine term which should be cos(2p*z/L)).
Alternatively or additionally, the Examiner takes official notice that apodization function having zero values at the ends of a length and a maximum value between the ends are well known in the art of apodized gratings. Such apodization functions would be obvious to a person of ordinary skill in the art as a suitable choice for an apodized grating with a suppressed/reduced ripple within a transmission/pass band (para. 0112 and 0125 of Tan).
Regarding claim 5, Tan cites, by way of example but not limitation, that the amplitude DW can be within 50 nm and 30 nm at the center portion of the sidewalls, while a width the channel waveguide can be within 500 nm (W1) and 400 nm (W2). Hence, Tan considers a range of the DW/W ratio from 30/400 = 7.5% to 50/500 = 10%. The range at least overlaps with the recited range and, hence, a prima facie case of obviousness exists (MPEP 2144.05).
It is also noted that (i) the range limit depends on a particular application (a particular wavelength of operation, etc); that (ii) the instant application does not provide any criticality for the exact values of the recited range limit; that (iii) it has been held that discovering the optimum or workable ranges of prior art involves only routine skill in the art (In re Aller, 105 USPQ 233); and that (iv) it has been held that "A recognition in the prior art that a property is affected by the variable is sufficient to find the variable result-effective." In re Applied Materials', Inc., 692 F.3d 1289, 1297 (Fed. Cir. 2012). It is well settled that it would have been obvious for an artisan with ordinary skill to develop workable or even optimum ranges for result-effective parameters. In re Boesch, 617 F.2d 272, 276 (CCPA 1980); see also In re Woodruff, 919 F.2d 1575, 1577-78 (Fed. Cir. 1990). The Tan – Adams combination considers the width and amplitude as result-effective parameters (determining the response ripple in the transmission/pass band).
Regarding claim 9, Tan teaches that the optical device further comprises a cladding arranged over the channel waveguide 102 and the plurality of optical elements 104 (para. 0045 and 0132).
Regarding claim 11, Tan teaches that the optical device can further comprise a grating coupler or an inverse tapering region at an end region of the channel waveguide (“In various embodiments, respective grating couplers or inverse tapering regions may be provided or formed at respective end regions of the channel waveguide 102” at para. 0070).
Regarding claim 13, Tan renders obvious that the plurality of optical elements can form a Bragg grating (para. 0113 and 0135).
Regarding claim 14, Tan illustrates (for the blue-edge in Fig. 7), by way of example but not limitation, that the separation between a stopband edge and a wavelength operation can be within 0.01 nm – 0.02 nm which at least overlaps with the recited range and, hence, a prima facie case of obviousness exists (MPEP 2144.05).
It is also noted that (i) the range limits depend on a particular application (a particular wavelength of operation, etc); that (ii) the instant application does not provide any criticality for the exact values of the recited range limit; that (iii) it has been held that discovering the optimum or workable ranges of prior art involves only routine skill in the art (In re Aller, 105 USPQ 233); and that (iv) it has been held that "A recognition in the prior art that a property is affected by the variable is sufficient to find the variable result-effective." In re Applied Materials', Inc., 692 F.3d 1289, 1297 (Fed. Cir. 2012). It is well settled that it would have been obvious for an artisan with ordinary skill to develop workable or even optimum ranges for result-effective parameters. In re Boesch, 617 F.2d 272, 276 (CCPA 1980); see also In re Woodruff, 919 F.2d 1575, 1577-78 (Fed. Cir. 1990). The Tan – Adams combination considers the separation between a stopband edge and a wavelength operation as a result-effective parameter (affecting dispersion and optical loss).
Regarding claim 15, the teachings of Tan and Adams combine (see the arguments and motivation for combining, as provided above for claim 1) to teach expressly or render obvious all of the recited limitations, as detailed above for claim 1. Specifically, the Tan – Adams combination considers an optical system (e.g., Figs. 6, 9, and 10 of Adams; 7:14 – 35 and 8:22 – 62) comprising (with reference to Fig. 6 of Adams):
an optical transmitter 71 for providing at least one optical signal (at one or more wavelengths, l1, … ln);
an optical fiber 11 coupled to the optical transmitter 70 for receiving and transmitting the at least one optical signal;
an optical device (e.g., 10a) for compensating dispersion of the at least one optical signal induced by the transmission in the optical fiber 11 (“a series of dispersion compensating fiber gratings (10a, 10b, 10c, 10d, . . . 10n)” at 7:26 – 28); and
an optical receiver 72 (“a length of optical fiber 11, and a multi-wavelength receiver 72” at 7:55 – 57).
The Tan – Adams combination considers that the optical device for compensating dispersion can be implemented as an integrated waveguide device disclosed by Tan and comprising (as detailed above for claim 1):
a channel waveguide 102 and two sidewalls coupled to at least a portion of the channel waveguide 102, the two sidewalls respectively arranged at opposing sides of the channel waveguide 102 along a longitudinal axis of the channel waveguide 102,
wherein each of the two sidewalls comprises a plurality of optical elements 104 arranged along the channel waveguide 102 of the waveguide, and the plurality of optical elements 104 are configured to interact with light propagating in the waveguide 102 so as to compensate dispersion of the light by transmitting the light in a regime close to a stopband of the plurality of optical elements 104 (rendered obvious by Tan and expressly taught by Adams) defined by a period L of the plurality of optical elements 104.
Regarding claim 17, the Tan – Adams combination considers that the optical transmitter 70,71 (in Figs. 6, 9, and 10) comprises a multiwavelength optical transmitter for providing a plurality of wavelength-distinct optical signal (wavelengths, l1, … ln; “a multi-wavelength transmitter 70” at 8:35 - 36) and the optical receiver comprises a multiwavelength optical receiver 72 (a multi-wavelength receiver 72” at 7:55 – 57).
Regarding claim 18, the Tan – Adams combination considers a rather wide range of operation around 1.55 mm (Figs. 3, 5, and 7 of Tan) and renders obvious that the multiwavelength optical transmitter can be configured to provide C-band (1530 – 1565 nm) and L-band (1565 - 1625 nm) wavelength optical signals.
Regarding claim 23, the Tan – Adams combination considers that the optical receiver 72 (in Figs. 6, 9, and 10 of Adams) is configured to convert optical signals to electrical signals.
Regarding claim 24, the Examiner takes official notice that the use of digital sampling oscilloscopes for analyzing electrical outputs of optical receivers, such as measurements of eye diagrams, is well known in the art of optical communications. Such equipment and measurements would be obvious to a person ordinary skill in the art in order to analyze the operation of a communication system comprising the contemplated dispersion compensating device.
Regarding claim 25, the teachings of Tan and Adams combine (see the arguments and motivation for combining, as provided above for claim 1) to teach expressly or render obvious all of the recited step limitations of a corresponding method of forming the contemplated optical device, as detailed above for claim 1. Specifically, the Tan – Adams combination considers a method for forming an optical device, the method comprising (with reference to Fig. 1A of Tan, as detailed above for claim 1):
forming a channel waveguide 102; and forming two sidewalls coupled to at least a portion of the channel waveguide by at least one of ion-implantation or photo lithography (para. 0109 and 0132 of Tan), the two sidewalls respectively arranged at opposing sides of the channel waveguide 102 along a longitudinal axis of the waveguide 102,
wherein each of the two sidewalls comprises a plurality of optical elements 104 extending to a respective side opposite to the portion of the channel waveguide 102 of the waveguide, and the plurality of optical elements 104 interact with light propagating in the waveguide so as to compensate dispersion of the light by transmitting the light in a regime close to a stopband of the plurality of optical elements 104 (rendered obvious by Tan and expressly taught by Adams) defined by a period L of the plurality of optical elements 104.
Regarding claim 26, the teachings of Tan and Adams combine (see the arguments and motivation for combining, as provided above for claim 1) to teach expressly or render obvious all of the recited limitations, as detailed above for claims 1 and 13. Specifically, the Tan – Adams combination considers an optical device comprising (with reference to Fig. 1A of Tan, as detailed above for claim 1):
a waveguide 102; and
a Bragg grating 104 (as detailed above for claim 13) defined in at least a portion of the waveguide 102,
wherein the Bragg grating is configured to interact with light propagating in the waveguide so as to compensate dispersion of the light by transmitting the light in a regime close to a stopband (rendered obvious by Tan and expressly taught by Adams) of the Bragg grating 104.
Regarding claim 27, the teachings of Tan and Adams combine (see the arguments and motivation for combining, as provided above for claim 1) to teach expressly or render obvious all of the recited limitations, as detailed above for claims 1, 2, 14, and 15.
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Tan in view of Adams, and further in view of “The Realization of Large-Scale Photonic Integrated Circuits and the Associated Impact on Fiber-Optic Communication Systems” by Welch et al, JOURNAL OF LIGHTWAVE TECHNOLOGY, vol. 24, No. 12, pp. 4674 – 4683, 2006 (hereinafter Welch).
Regarding claim 16, Tan teaches that the dispersion-compensating device is an integrated-optic device on a chip/substrate 201 (Fig. 2; para. 0071 and 0115). While Tan does not state that the dispersion-compensating device can be integrated with other components to form an optical transmitter as a system-on-a-chip, Welch describes (Fig. 1; Abstract; Sections II and III) large-scale photonic integrated circuits and states that “… InP supports light generation, amplification, modulation, and detection, … Passive optical functions such as wavelength multiplexing, demultiplexing, variable optical attenuation, switching, and dispersion compensation can also be implemented in InP. Since devices can be monolithically interconnected by “on-chip” waveguides, InP-based LS PICs enable the fabrication of an optical “system-on-a-chip” that can provide substantial benefits over discrete devices” (1st para. of Section III).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention that the integrated-optic dispersion-compensating device can be integrated, in accordance with the teachings of Welch, with an optical transmitter or an optical receiver in a manner that the optical transmitter or the optical receiver is a system-on-a-chip, the latter being a compact and mechanically rugged system (compared to using discrete components).
Claims 19 – 22 are rejected under 35 U.S.C. 103 as being unpatentable over Tan in view of Adams, and further in view of Ghuman (US 2022/0190948 A1).
Regarding claim 19, while Tan does not illustrate a wide variety of possible/suitable application areas and systems in which the disclosed dispersion-compensating device may be deployed, Ghuman discloses (Figs. 1 and 14; para. 0037 – 0051, 0056 – 0072, and 0193 – 0210) an optical system (headend) 101 comprising a transmitting part 190, a receiving part 188, and a dispersion-compensating device DCM 112,114 (Dispersion Compensation Module; para. 0051 and 0056), wherein the optical transmitter is configured to provide modulated signals including Pulse Amplitude Modulation (PAM) and non-return-to-zero (NRZ) modulated signals (para. 0039, 0053, and 0299).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention that the disclosed dispersion-compensating device of Tan can be deployed as one of more of the DCMs in the system of Ghuman as a suitable application area/system in order to compensate dispersion over fiber-optic links, as considered by Tan (para. 0041 and 0042 of Tan), Adams (Figs. 6 – 10), and Ghuman (para. 0050 and 0051).
Regarding claims 20 and 21, the Tan – Adams – Ghuman combination considers that the optical fiber can be a single mode fiber (e.g., para. 0170 of Ghuman) which is one of the two types of fibers (single-mode and multi-mode) and has less dispersion (absence of intermodal dispersion) compared to multi-mode fibers which allows for longer fiber spans before dispersion compensation is needed, for example, between 5 km and 60 km (para. 0038 of Ghuman). This range at least overlaps with the range recited by claim 21 and, hence, a prima facie case of obviousness exists (MPEP 2144.05)
Regarding claim 22, the Tan – Adams – Ghuman combination considers that the optical system (headend) can further comprise (Fig. 14 of Ghuman):
an erbium doped fiber amplifier 1436 (OPA = optical pre-amplifier; “The optical pre-amplifier may also be an EDFA” at para. 0047; “The one or more optical data signals 10GbE UP 1435 may be amplified by OPA 1436” at para. 0207) and a bandpass filter (within WDM 1418; “The WDM may comprise one or more thin film filters (TFFs)” at para. 0040) coupled between the optical fiber 174,176 and the optical dispersion-compensating device 1438 (“DCM 1438 may be similar in functionality to DCM 112” at para. 0193), wherein the optical device is configured to receive an output from the bandpass fiber (in WDM 1418) and to compensate dispersion of the output (para. 0051).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
US 2003/0039442 A1
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/ROBERT TAVLYKAEV/Primary Examiner, Art Unit 2896
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