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
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 8/31/26 has been entered. Claims 1, 9, and 17 have been amended, claims 3, 11, and 19 canceled, and claims 22 – 24 added. Claims 1, 2, 4 – 10, 12, 14 – 18, and 20 – 24 are pending.
Response to Amendments / Arguments
Applicant’s amendments have necessitated claim objections, as detailed below.
Applicant’s amendments have necessitated rejections under 35 USC 112(a), as detailed below.
Applicant’s arguments regarding the previously raised claim rejections under 35 USC 103 have been fully considered but they are moot in view of the new grounds of rejections, as necessitated by Applicant’s amendments. Specifically, the new limitations in the independent claims define ranges of the effective nonlinear parameter and the propagation loss parameter. Canceled claims 3, 11, and 19, for which the Examiner previously took official notice in the Office Action of 11/19/25, recited similar ranges (with a higher upper limit) of the propagation loss parameter. Hence, Applicant in effect traversed, in a retroactive manner, the official notice. Accordingly, the Examiner additionally applies an NPL reference by Wu et al that has been yielded by an updated prior art search and describes low-loss waveguides in lithium niobate with propagation loss coefficients down to 0.027 dB/cm. In combination with other prior art of record, Wu teaches expressly or renders obvious all of the limitations recited by the amended claims, as detailed below.
New claims 22 – 24 are rejected as detailed below.
Claim Objections
Claims 1, 2, 4 – 10, 12, 14 – 16, and 21 – 23 are objected to because of the following informalities:
Claims 1 and 9 each recite the limitation “the first material comprises an effective nonlinear parameter” which has a deficiency of style. A waveguide structure in a nonlinear material may be characterized by, or associated with, the effective nonlinear parameter g, (see the rejections below under 35 USC 112), but the nonlinear material per se cannot comprise the effective nonlinear parameter g. As an analogy, a car may be characterized by, or associated with, a range of speeds the car is capable of reaching, but the car per se does not comprise such speed range. For the purposes of this Action and in view of the rejections under 35 USC 112, the limitation is interpreted as “the first material is associated with an effective nonlinear parameter”. Appropriate corrections are required.
Claim Rejections - 35 USC § 112
Claims 1, 2, 4 – 10, 12, 14 – 18, and 20 – 24 are rejected under 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph, as based on a disclosure which is not enabling. The disclosure does not enable one of ordinary skill in the art to practice the invention without knowing how to enable the recited range of the effective nonlinear parameter, which is/are critical or essential to the practice of the invention but not included in the claim(s). See In re Mayhew, 527 F.2d 1229, 188 USPQ 356 (CCPA 1976). Specifically, the effective nonlinear parameter g (also known as the Self-Phase Modulation parameter) is defined by the following well-known expression:
γ
=
2
π
λ
n
2
A
e
f
f
wherein l is the wavelength of operation [m], n2 is the Kerr coefficient [m2/Watt], and Aeff is the effective mode area [m2], as evidenced by an NPL reference “Effective Nonlinear Coefficient” by Paschotta.
The instant specification (para. 0025 and 0026) and the claims merely list a lower range limit of the effective nonlinear parameter g without describing at least one example/embodiment with a full set of values of l, n2, and, most importantly, Aeff. The latter is not determined by only the nonlinear material, but also by the properties (transverse sizes, shape, etc) of a particular waveguide implemented in the nonlinear material.
For the purposes of this office action, the limitations reciting a range of the effective nonlinear parameter g are interpreted as being drawn to a waveguide formed in the first (nonlinear) material and capable of reaching the recited range of the effective nonlinear parameter g.
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, 2, 4 – 10, 12, 14 – 18, 20, and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Ono (US 6,411,765 B1) in view of Godet et al (US 2019/0318957 A1), in view of Lin (US 2020/0103344 A1), in view of “Strip/slot hybrid arsenic tri-sulfide waveguide with ultra-flat and low dispersion profile over an ultra-wide bandwidth” by Jafari et al, OPTICS LETTERS, vol. 38, No. 16, pp. 3082 – 3085, 2013 (hereinafter Jafari), and further in view of “Long Low-Loss-Lithium Niobate on Insulator Waveguides with Sub-Nanometer Surface Roughness” by Wu et al, Nanomaterials, vol. 8, paper 910, pp. 1 – 8, 2018 (hereinafter Wu), as evidenced by “Effective Nonlinear Coefficient” by Paschotta (hereinafter Paschotta).
Regarding claims 1 and 2, Ono discloses (Fig. 6; 7:59 – 8:51) a photonic waveguide structure, comprising (see annotated last drawing in Fig. 6 below):
at least four photonic waveguide layers disposed in a stack configuration, wherein:
a first (e.g., the bottommost) photonic waveguide layer 162, of the at least four photonic waveguide layers 162,170,178,186, includes a first cladding layer 154 and a first waveguide core structure 158,
wherein the first cladding layer 154 is configured to confine light within the first waveguide core structure 158 (to enable light guiding in/along the first waveguide core structure 158 due to a lower reflective index in the first cladding layer 154, “a specific difference in the specific refraction factor is created between the first clad layer 154 and the first core layer 156” at 8:81 – 3; “the core portions constituting the optical coupler in the structure fulfill a function of guiding light energy, a function of relay coupling two other core portions or a function achieving a combination of these functions” at 3:16 – 20; “A optical waveguide element, having n substantively planar light-wave circuit layers, each constituted of a core portion for receiving and guiding a light signal and a clad layer covering said core portion” in claim 1),
wherein the first waveguide core structure 158 comprises a first material (12:36 – 45);
a second photonic waveguide layer 170, of the at least four photonic waveguide layers 162,170,178,186, includes a second cladding layer 160 and a second waveguide core structure 166 associated with a propagation loss parameter that satisfies a propagation loss parameter threshold,
wherein the second cladding layer 160 is configured to confine light within the second waveguide core structure 166 (by the same mechanism/principle as that for the first waveguide core structure 158),
wherein the second cladding layer 160 is between the first waveguide core structure 158 and the second waveguide core structure 166 (as seen in Fig. 6), and
wherein the second waveguide core 166 structure comprises a second material (12:36 – 45); and
a third photonic waveguide layer 178, of the at least four photonic waveguide layers 162,170,178,186, includes a third cladding layer 168 and a third waveguide core structure 174,
wherein the third cladding layer 168 is configured to confine light within the third waveguide core structure 174 (by the same mechanism/principle as that for the other waveguide core structures and cladding layers, as detailed above),
wherein the third cladding layer 168 is between the second waveguide core structure 166 and the third waveguide core structure 174 (as seen in Fig. 6), and
wherein the third waveguide core structure 174 comprises a third material (12:36 – 45).
PNG
media_image1.png
653
1649
media_image1.png
Greyscale
Annotated bottommost drawing in Fig. 6 of Ono.
In one of the disclosed embodiments, Ono uses, by way of example but not limitation, silica (SiO2) based compositions for the core structures and cladding layers (7:63 – 65), but also considers a wide variety of other suitable/workable materials for other embodiments (“While optical waveguide elements with their clad layers and their core portions constituted of SiO2 are used as examples in the explanation of embodiments, the present invention is not limited to these examples. The present invention may be adopted in a optical waveguide element with at least either clad layers or core portions thereof constituted of any of various other source materials. For instance, the clad layers or the core portions may be constituted of an organic material such as an epoxy or a polyurethane, a chalcogenide material such as arsenic sulfide, an electro-optical crystalline material such as lithium niobate or lithium tantalate, a magnetic material such as yttrium iron garnet, a metal oxide such as zinc oxide or gallium aluminum arsenide” at 12:33 – 45). The listed materials include both passive materials (e.g., SiO2) and active materials for waveguide core structures. Thus, Ono generally renders obvious embodiments wherein some or all of the waveguide core structures are formed by active materials (e.g., As2S3, AlGaAs, and LiNbO3). In particular, Ono renders obvious an embodiment wherein the first waveguide core structure 158 is formed of such active material as As2S3 and is a first active structure associated with a Kerr coefficient that satisfies the Kerr coefficient threshold (≥ 1 x 10-18 m2/W). The second waveguide core structure 166 can be formed of a second active material, such as LiNbO3 (which has low optical loss and commonly used for making optical waveguides) and associated with a propagation loss parameter that satisfies a propagation loss parameter threshold. The second active structure comprises the second material (LiNbO3) that is different from the first material (As2S3). Similarly, the third waveguide core structure 174 can comprise a third active material (e.g., AlGaAs), the third material (AlGaAs) being different from the first material (As2S3) and the second material (LiNbO3). Annotated Fig. 6 above illustrates such selection of active materials.
Ono discloses a vertical waveguide layer stack that comprises active material cores (e.g., As2S3, LiNbO3, and AlGaAs) and passive material claddings (SiO2) and has essential features similar/identical to those illustrated in Fig. 1 of the instant application and listed at para. 0022 and 0033 of the instant specification (published as US 2023/0146862 A1). While Ono does not expressly teach suitable designs/permutations with different active materials in different layers (feature i) and with different atomic structures (crystalline or amorphous) (feature ii) and does not detail characteristics of constituent materials, such as the Kerr coefficient and the effective nonlinear coefficient (feature iii), and the propagation loss parameter (feature iv), Godet, Lin, and Jafari, and Wu provide features i – iv respectively, as detailed below.
As for feature (i), as detailed above, Ono generally renders obvious that waveguide cores in different photonic layers can be formed of different materials, but does not expressly state so. However, Godet discloses (Figs. 2 and 3; 0007 and 0043 – 0054) a photonic structure comprising at least four photonic layers disposed in a stack configuration (“In other examples, four or more optical element layers can be stacked to form an optical device” at para. 0051), wherein the photonic structure is fabricated, layer by layer, similarly to the photonic structure in Ono, and wherein each layer comprises patterned regions of higher refractive index (e.g., 206, 212, and 216 in Fig. 3) that are covered by cladding layers 208,214,218 of lower refractive index (para. 0036 and 0047). Godet expressly states that the high-index regions in different photonic layers can be formed of different materials (“In other examples, operations 104-108 can repeated for a plurality of iterations (cycles) that may employ the same or differing materials, heights, and patterns. Depending on the example, stacked optical element layers can be formed from the same or different materials. This cycle (of operations 104-108) can be repeated from 2-100 times to form a plurality of stacked optical element layers” at para. 0038). 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 first active structure, the second active structure, and the third active structure can be formed of 3 active materials that are different from one another (e.g., As2S3, AlGaAs, and LiNbO3, which are all cited by Ono as suitable active materials), as generally rendered obvious by the teachings of Ono and expressly taught by Godet.
As for feature (ii), Ono cites crystalline active materials (lithium niobate; 12:33 – 45) and Godet mentions crystalline or non-crystalline/amorphous silicon, but the Ono – Godet combination does not state that an active material, such as As2S3 (listed by Ono), can have a non-crystalline/amorphous structure. However, Lin discloses (Figs. 1A and 1B; Abstract; para. 0021 and 0022) an optical waveguide 102 comprising a non-crystalline/amorphous active material, in particular, a chalcogenide glass (comprising sulfur, selenium or tellurium (para. 0021)), such as As2S3 which is one of the suitable active materials listed by Ono. 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 first material of the Ono – Godet combination, such as As2S3, can have a non-crystalline/amorphous active structure as a common form of As2Ge3 (chalcogenide glass).
As for feature (iii), As2S3 is listed by both Ono (12:33 – 45) and by the instant specification (para. 0022) as a suitable active material for the first active structure. As2S3 is associated with several nonlinear optical characteristics, including the Kerr coefficient n2. and the effective nonlinear parameter g, the latter being dependent on n2. While Ono does not cite such parameters associated with As2S3, Jafari describes (Figs. 1, 4, and 5; Eq. 3; pp. 3082 – 3083) a waveguide formed in As2S3 and exemplifies that As2S3 has a large Kerr coefficient n2 of at least 3 x 10-18 m2/W (para. bridging columns on p. 3083) and a large effective nonlinear parameter g (defined by Eq. 3) of at least 2 rad/(Watt*m) at wavelengths shorter than 2 mm, as seen in Fig. 4. The latter shows that the effective nonlinear parameter g rapidly increases at shorter wavelengths (because g is inversely proportional to the wavelength l and the effective mode area, as shown by Eq. (3).
As a relevant comment, it is noted that the unit of the effective nonlinear parameter g has a dimensionless enumerator, as evidenced by para. 0025 of the instant application and by Paschotta (Section “Kerr Nonlinearity in an Optical Fiber”), and it is sometimes assigned [radian], because effective nonlinear parameter g is used to calculate a nonlinear phase (in radians, according to the last equation in the Section “Kerr Nonlinearity in an Optical Fiber” of Paschotta).
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 first nonlinear material (e.g., As2S3) in Ono can be associated with large values of the Kerr coefficient n2 (≥ 3 x 10-18 m2/W) and the effective nonlinear parameter g (≥ 2 rad/(Watt*m)), as exemplified by Jafari, in order to improve/increase the efficiency of nonlinear interactions/processes in the first photonic waveguide layer.
The Ono – Godet – Lin – Jafari combination considers ranges of the Kerr coefficient n2 and the effective nonlinear parameter g that at least overlap 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 (e.g., a wavelength of operation, particualr active materials, desired efficiency of nonlinear processes, etc); that (ii) the instant application does not provide any criticality for the exact values of the recited range limits; and 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).
As for feature (iv), the Ono – Godet – Lin – Jafari combination considers that the second material can be lithium niobate (12:33 – 45 of Ono), but does not exemplify typical values of propagation loss in lithium niobate waveguides. However, Wu describes (Figs. 1 – 3; Abstract; Sections 1 and 2) waveguides formed in lithium niobate (LiNbO3) and states that their losses can be as low as 0.027 dB/cm (Abstract). It would be obvious to a person of ordinary skill in the art that the second material (lithium niobate), as considered by the Ono – Godet – Lin – Jafari combination, can have a propagation loss parameter threshold that is less than or equal to 0.027 dB/cm, as exemplified by Wu, so that low-loss optical propagation is ensured.
In light of the foregoing analysis, the Ono – Godet – Lin – Jafari – Wu (OGLJW) combination teaches expressly or renders obvious all of the recited limitations.
To sum up the applied prior art, Ono discloses a layered stack comprising at least 4 layers that comprise active materials, such as As2S3 and LiNbO3. Godet teaches that different layers can comprises different active materials. Lin specifies that As2S3 can have an amorphous form. Jafari and Wu cite values of the Kerr coefficient and the effective nonlinear coefficient in As2S3 and the propagation loss parameter in LiNbO3.
Regarding claims 9, 10, 17, and 18, the teachings of Ono, Godet, Lin, Jafari, and Wu 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 defining an optical device that comprises the contemplated stacked photonic waveguide structure, as detailed above for claims 1, 2, and 7.
Regarding claims 4, 12, and 20, the OGLJW combination considers that the first active structure and the second active structure can each configured to transmit light with wavelengths from the visible to the near-infrared within which As2S3, AlGaAs, LiNbO3, and SiO2 are transparent and have low optical loss (“the light-wavelength is approximately 1.31 micrometer” at 10:33 – 34 of Ono; para. 0031 of Godet). Hence, the OGLJW combination considers a wavelength range that at least overlaps with the recite range and, hence, a prima facie case of obviousness exists (MPEP 2144.05).
Regarding claims 5 and 15, the OGLJW combination considers that respective thicknesses of the first active structure and the second active structure can be greater than or equal to 500 nm (8 mm x 8 mm at 10:32 – 35 of Ono; Jafari describes that waveguides in As2S3 can have thicknesses over 500 nm (para. bridging columns on p. 3083). It is also noted that it would be well within ordinary skill in the art of optical waveguides (which is noted as being high) to determine workable/optimum waveguide cross-sections for an intended wavelength of operation.
Regarding claims 6 and 16, the OGLJW combination considers that the first photonic waveguide layer and the second photonic waveguide layer can be formed using one or more sputtering processes (4:36 – 39 of Ono).
Regarding claim 7, the OGLJW combination considers that the at least four photonic waveguide layers are disposed in the stack configuration over a substrate (identified as 152 in Fig. 5 of Ono). The OGLJW combination does not limit the order of the stacked layers so that the first photonic waveguide layer can be disposed over or under the second photonic waveguide layer in the stack configuration as a matter of renumbering/renaming of the layers.
As an aside, it is also noted that the stacked layer structure in Fig. 6 of Ono has essential structural features substantially similar/identical to those in Fig. 1 of the instant application.
Regarding claim 8, the OGLJW combination considers that the third photonic waveguide layer is disposed over the second photonic waveguide layer in the stack configuration (see annotated Fig. 6 of Ono provided above for claim 1).
Regarding claim 14, the OGLJW combination renders obvious a wide variety of suitable/workable active (nonlinear) materials and their combinations. In the latter case, there can be a fourth material included in the first active structure and the second active structure. For example, AlGaAs and InGaAsP both include Ga and As. It is also noted that it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. See In re Leshin, 125 USPQ 416.
Regarding claim 21, the OGLJW combination considers that the contemplated photonic waveguide structure can further comprise a fourth photonic waveguide layer 186, of the at least four photonic waveguide layers 162,170,178,186 (see annotated Fig. 6 of Ono provide above for claim 1), includes a fourth cladding layer and a fourth active structure,
wherein the fourth cladding layer is configured to confine light within the fourth active structure (just as the other cladding layers),
wherein the fourth cladding layer is between the third active structure and the fourth active structure, and
wherein the fourth active structure comprises a fourth material (e.g., lithium tantalate; at 12:33 – 45 of Ono) which may be different from the first material (As2S3), the second material (LiNbO3), and the third material (AlGaAs).
Claims 22 – 24 are rejected under 35 U.S.C. 103 as being unpatentable over Ono in view of Godet, in view of Lin, in view of Jafari, in view of Wu, and further in view of Heussler et al (US 2021/0231889 A1).
Regarding claims 22 – 24, the OGLJW combination considers that the first photonic waveguide layer and the second photonic waveguide layer can each comprise a SiO2 cladding (12:33 – 45 of Ono) covering a waveguide core of an active material (As2S3 and LiNbO3 respetively), the latter formed using one or more sputtering processes (4:36 – 39 of Ono). While Ono does not specify a temperature of such sputtering process, Heussler discloses (Abstract) a method of manufacturing a variety of optical devices, the method comprising a low-temperature sputtering process for a SiO2 protection layer, the low-temperature sputtering process performed at temperatures less than 100oC (para. 0113). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention that at least a SiO2 cladding of the first photonic waveguide layer and the second photonic waveguide layer can be formed by a low-temperature sputtering process at a temperature less than 100oC in order to preserve the properties of the underlying active materials (forming the waveguide cores) (“Examples of the first protection layer include but are not limited to silicon dioxide (SiO2) or the like. In some exemplary embodiments, SiO2 is deposited by sputtering or evaporation at a low temperature (e.g., <100° C) to preserve the integrity of the underlying layer(s)” at para. 0113 of Heussler, emphasis added).
The OGLJWH combination considers a range of temperature that at least overlaps with the recited ranges and, hence, a prima facie case of obviousness exists (MPEP 2144.05)
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
“Nonlinear optical waveguides in As2S3-Ag2S chalcogenide glass thin films” by Almeida et al, OPTICAL MATERIALS EXPRESS, vol. 7, No. 1, pp. 93 – 99, 2017, lists values of nonlinear characteristics/parameters associated with As2S3.
“Application Notes and Protocols: Arsenic Trisulfide (As2S3) in Nonlinear Optical Devices” by BenchChem Technical Support Team, lists values of nonlinear characteristics/parameters associated with As2S3.
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/ROBERT TAVLYKAEV/Primary Examiner, Art Unit 2896
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