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 .
Response to Arguments
Applicant’s arguments with respect to claim(s) 7-9 and 12-20 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
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)(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.
Claim(s) 7-9, 16, and 18 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Ning et al. (CN 112558227 A).
Re claim 7, Ning et al. discloses an integrated circuit comprising: a substrate (an inherent supporting feature); and an optical waveguide (fig. 5) on the substrate (silicon waveguide is inherently disposed on a substrate; English Translation, abstract), the optical waveguide configured for wavelength division multiplexing (WDM) an optical signal (fig. 5; English Translation, p. 2, first two paragraphs), the optical waveguide comprising: a first port (fig. 5; input port); a first stage comprising a first cascaded Mach-Zehnder interferometer (MZI) filter and a first pair of cascaded MZI filters (fig. 5; English Translation, p. 5, 2nd to last paragraph); wherein the first cascaded MZI filter is coupled to the first port (fig. 5); wherein the first pair (top and bottom) of cascaded MZI filters are coupled to the first cascaded MZI filter (fig. 5); wherein the first cascaded MZI filter comprises one or more passbands (multi-wavelength; figs. 4-5), and the first pair of cascaded MZI filters each comprise one or more passbands (multi-wavelength; fig. 5), the first cascaded MZI filter comprising a nonlinear taper (5, 6) having a convex shape (parabolic type) with a width increasing nonlinearly along a length of the nonlinear taper (English Translation, p. 2, 2nd to last paragraph: the structure can be parabolic type, which is nonlinear), the nonlinear taper (5, 6) transitioning between a thinner section and a thicker section of the optical waveguide and having a width that increases nonlinearly along a first length, a second length of the nonlinear taper (fig. 3; English Translation, p. 4, last paragraph. Second length is considered as straight/nearly straight portion, which is an inherent feature of a nonlinear taper, while the first length is a curved/parabolic/convex portion); and a plurality of second ports (fig. 5). Note that the limitation of “being selected to reduce optical loss” is a property of the second length of nonlinear taper which is presumed to be inherent to the structure of the device of Ning et al.. When a structure recited in a reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent. See MPEP 2112.01. The patentability of a product depends only on the claimed structural limitations of the product. Ning et al. teaches a nonlinear taper (parabolic) which are substantially identical to the claimed invention (transition structure 5 and 6 shown in fig. 1 of Ning et al. are similar to structure 404a-d shown in fig. 4B of the instant application), therefore the claimed property is presumed to be inherent. Ning et al. further discloses structures 5 and 6 are used for reducing transition loss (English Translation, p. 4, 3rd paragraph to last). The burden is on the applicant to show that the prior art device does not possess the claimed properties or is not capable of these functional characteristics. See MPEP 2112.01.
Re claim 8, Ning et al. discloses the integrated circuit of claim 7, wherein each of the first cascaded MZI filter and the first pair of cascaded MZI filters comprises a first arm (left) and a second arm (right); wherein the first arm and the second arm are phase compensated such that a first index change in each first arm is cancelled with a second index change of each second arm (the interference arms width W1 and W2 and length L1 and L2 can adjust the effective refractive index related to the width to eliminate the influence of the MZI waveguide width change to the effective refractive index (English Translation, p. 3, last paragraph), which is interpreted as the first arm and the second arm are phase compensated such that a first index change in the first arm is cancelled with a second index change of the second arm).
Re claim 9, Ning et al. discloses the integrated circuit of claim 8, wherein each first arm comprises one or more first phase sections (1 and 2); wherein the one or more first phase sections each include a first length (L1) and a first width (W1); wherein each second arm comprises one or more second phase sections (3 and 4); wherein the one or more second phase sections each comprise a second length (L2) and a second width (W2); wherein each first arm and each second arm are phase compensated based on the first width, the first length, the second width, and the second length (English Translation, p. 3, last paragraph); wherein the first width is greater than the second width (fig. 1).
Re claim 16, Ning et al. discloses the integrated circuit of claim 7, wherein the optical waveguide is formed of a silicon nitride film (English Translation, p. 2, last paragraph).
Re claim 18, Ning et al. discloses the integrated circuit of claim 7, wherein at least one of: the optical waveguide is configured as a demultiplexer (English Translation, claim 9), the first port is an input port (fig. 5), and the plurality of second ports are output ports (fig. 5).
Claim Rejections - 35 USC § 103
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 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.
Claim(s) 7 and 12-18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hung et al. US 2023/0228944 A1 (hereinafter “Hung”) in view of Seyringer (DE 102006027681 A1).
Regarding claim 7, Hung teaches an integrated circuit (“wavelength division multiplexer and demultiplexer” 100; [0038]; FIGs. 1, 2A-B, 5A-B) comprising: a substrate ([0038] discloses that the integrated circuit 100 may be disposed on a substrate); and an optical waveguide (“first waveguide structure” 110, “second waveguide structures” 121, 122; [0038]; FIG. 1) on the substrate, the optical waveguide configured for wavelength division multiplexing (WDM) (the integrated circuit 100 is described as a wavelength division multiplexer and demultiplexer [0038]) an optical signal (“input optical beam” LS; [0041]; FIG. 1), the optical waveguide comprising: a first port (IN1; FIG. 5A); a first stage (110) comprising a first cascaded Mach-Zehnder interferometer (MZI) filter (“first-stage MZI structure” S11; [0052] discloses that filter S11 may be the structure shown in FIG. 5A, which is a cascaded MZI filter) and a first pair of cascaded MZI filters (“second-stage MZI structures” S12A, S12B; [0052] discloses that filters S12A and S12B may be the structure shown in FIG. 5A); wherein the first cascaded MZI filter is coupled to the first port (IN1 becomes the port where optical signal LS is input to the device in FIG. 1); wherein the first pair of cascaded MZI filters are coupled to the first cascaded MZI filter ([0054]; FIG. 1); wherein the first cascaded MZI filter and the first pair of cascaded MZI filters each comprise one or more passbands (“channels” CH1-4; [0054]-[0055]; FIG. 1), the first cascaded MZI filter comprising a taper ([0046] discloses that both arms of the optical waveguide may comprises “tapered waveguide sections” with lengths T1/2 and T2/2, respectively; see also FIGs. 4A, 5A) with a width increasing along a length of the taper (a changing width along a certain length is understood to be inherent to a structure described as a “taper”); the taper transitioning between a thinner section and a thicker section of the optical waveguide and having a width that increases along a first length (fig. 4A); and a plurality of second ports (OUT1 and OUT2; FIG. 5A).
Hung does not teach that the taper is a nonlinear taper having a convex shape and having a second length being selected to reduce optical loss.
Seyringer teaches an optical waveguide with a nonlinear taper (22) for an optical multiplexer/demultiplexer (fig. 1). The nonlinear taper (22) having a convex shape with a width that increases nonlinearly along a first length (between BP1 and BP2), transitioning between a thinner section (21) and a thicker section (23), and a second length (23 section; English Translation, p. 4, 1st paragraph).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the instant application to use Seyringer’s nonlinear taper in Hung’s device since such modification would have been an obvious design variation, well within the ordinary skill in the art, since it has been held that the selection of a known material based on its suitability for its intended use such as audio application. In re Leshin, 125 USPQ 146.
Note that the limitation of “being selected to reduce optical loss” is a property of the second length of nonlinear taper which is presumed to be inherent to the structure of the device of Hung/Seyringer. When a structure recited in a reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent. See MPEP 2112.01. The patentability of a product depends only on the claimed structural limitations of the product. Seyringer et al. teaches a nonlinear taper having a convex shape section (fig. 1), therefore the claimed property is presumed to be inherent. Seyringer further discloses the taper are designed for reducing transition/crosswalk loss (English Translation, p. 5, 2nd to last paragraph). The burden is on the applicant to show that the prior art device does not possess the claimed properties or is not capable of these functional characteristics. See MPEP 2112.01.
Re claim 12, Hung/Seyringer discloses the integrated circuit of claim 7. Hung further discloses the optical waveguide is a two-stage optical waveguide comprising the first stage (110) and a second stage (121 and 122; FIG. 1); wherein the plurality of second ports comprises four ports (FIG. 1); wherein the second stage comprises: a second cascaded MZI filter (“first-stage MZI structure” S21 in optical waveguide 121; [0052] discloses that filter S21 may be the structure shown in FIG. 5B, which is a cascaded MZI filter) and a second pair of cascaded MZI filters (“second-stage MZI structures” S22A, S22B in optical waveguide 121; [0052] discloses that filters S22A and S22B may be the structure shown in FIG. 5B); wherein the second cascaded MZI filter is coupled to a first of the first pair of cascaded MZI filters (S12A; FIG. 1); wherein the second pair of cascaded MZI filters are each coupled to the second cascaded MZI filter (FIG. 1); wherein a first of the second pair of cascaded MZI filters (S22A) comprises a first passband (CH1) of the one or more passbands; wherein a second of the second pair of cascaded MZI filters (S22B) comprises a second passband of the one or more passbands (CH2); and a third cascaded MZI filter (S21 in optical waveguide 122) and a third pair of cascaded MZI filters (S22A and S22B in optical waveguide 122); wherein the third cascaded MZI filter is coupled to a second of the first pair of cascaded MZI filters (S12B; FIG. 1); wherein the third pair of cascaded MZI filters are each coupled to the third cascaded MZI filter (FIG. 1); wherein a first of the third pair of cascaded MZI filters (S22A) comprises a third passband (CH3); wherein a second of the third pair of MZI filters (S22B) comprises a fourth passband (CH4).
Regarding claim 13, Hung/Seyringer discloses the integrated circuit of claim 12. Hung further discloses the first of the second pair of cascaded MZI filters (S22A in optical waveguide 121; [0052]; FIGs. 1, 5B) is interleaved with the second of the second pair of cascaded MZI filters (S22B in optical waveguide 121; [0052]; the examiner notes that the term “interleaved” is given its broadest reasonable interpretation in light of the instant specification, in particular paragraph [0116], and that when the filters shown in Hung FIG. 5B are placed adjacent to and offset from each other as suggested by FIG. 1, they are considered to be “interleaved”); the second of the second pair of cascaded MZI filters (S22B in optical waveguide 121) is interleaved with the first of the third pair of cascaded MZI filters (S22A in optical waveguide 122; the examiner notes that the term “interleaved” is given its broadest reasonable interpretation in light of the instant specification, in particular paragraph [0116], and that when the filters shown in Hung FIG. 5B are placed adjacent to and offset from each other as suggested by FIG. 1, they are considered to be “interleaved”); or the first of the third pair of cascaded MZI filters (S22A in optical waveguide 122) is interleaved with the second of the third pair of cascaded MZI filters (S22B in optical waveguide 122. Notes that the term “interleaved” is given its broadest reasonable interpretation in light of the instant specification, in particular paragraph [0116], and that when the filters shown in Hung FIG. 5B are placed adjacent to and offset from each other as suggested by FIG. 1, they are considered to be “interleaved”).
Regarding claim 14, Hung/Seyringer discloses the integrated circuit of claim 13. Hung further discloses the first of the second pair of cascaded MZI filters (S22A in optical waveguide 121; [0052]; FIGs. 1, 5B) is interleaved with the second of the second pair of cascaded MZI filters (S22B in optical waveguide 121; [0052]; FIGs. 1, 5B) by being offset from the second of the second pair of cascaded MZI filters (see FIG. 1 – the orientation shown in this schematic suggests that the two filters in the second pair of cascaded MZI filters should be offset from each other).
Regarding claim 15, Hung/Seyringer discloses the integrated circuit of claim 14. Hung further discloses the first of the second pair of cascaded MZI filters (S22A in optical waveguide 121; [0052]; FIGs. 1, 5B) comprises one or more directional couplers (“optical couplers” 212B, 214B, 216B; [0044]; FIGs. 2B, 5B); wherein the second of the second pair of cascaded MZI filters (S22B in optical waveguide 121) comprises one or more bent sections (“curved sections” 222B11, 222B21, 224B11, 224B21; [0050]; FIG. 5B); wherein the one or more directional couplers are adjacent to the one or more bent sections (see FIG. 1 – the orientation shown in this schematic suggests that the two filters in the second pair of cascaded MZI filters should be adjacent to each other and therefore it follows that the components of each filter are adjacent to the components of the other filter).
Regarding claim 16, Hung/Seyringer discloses the integrated circuit of claim 7. Hung further discloses the optical waveguide (110, 121, 122) is formed of a silicon nitride film ([0038]: “The first waveguide structure 110 and the second waveguide structures 121, 122 may be waveguide structures formed of silicon, silicon nitride or another material” – the silicon nitride is understood to be a layer or film, since it is formed on top of a substrate, and therefore meets the broadest reasonable interpretation of the instant claim).
Regarding claim 17, Hung/Seyringer discloses the integrated circuit of claim 16. Hung further discloses a dummy structure around the optical waveguide (110, 121, 122); wherein the dummy structure is formed of the silicon nitride film. Specifically, as seen in FIG. 1, the optical waveguide comprises several ports which do not couple to any inputs or outputs (see, e.g., on FIG. 1: lower left-hand port of filter S11, upper left-hand ports of filters S12A and S12B, and lower right-hand ports of filters S12A and S12B). Under the broadest reasonable interpretation of the claim element “dummy structure,” these ports which do not input or output any optical signal may be considered a dummy structure around the optical waveguide, and the dummy structure is formed of the same material as the optical waveguide, which is disclosed to be silicon nitride ([0038]).
Regarding claim 18, modified Hung 7 additionally teaches that the optical waveguide (110, 121, 122) is configured as a demultiplexer (see FIG. 1 – input optical signal LS is split, i.e., demultiplexed, into four wavelengths/channels CH1-4), the first port is an input port (FIG. 1), and the plurality of second ports are output ports (FIG. 1 – channels CH1-4 are output from the plurality of second ports).
Claim(s) 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hung et al. US 2023/0228944 A1 (hereinafter “Hung”) in view of Seyringer (DE 102006027681 A1) and Fincato et al. US 2021/0041644 A1 (hereinafter “Fincato”).
Regarding claim 19, Hung teaches an integrated circuit (“wavelength division multiplexer and demultiplexer” 100; [0038]; FIGs. 1, 2A-B, 5A-B) comprising: a substrate ([0038] discloses that the integrated circuit 100 may be disposed on a substrate); and an optical waveguide (“first waveguide structure” 110, “second waveguide structures” 121, 122; [0038]; FIG. 1) formed of a silicon nitride film ([0038]: “The first waveguide structure 110 and the second waveguide structures 121, 122 may be waveguide structures formed of silicon, silicon nitride or another material”) on the substrate, the optical waveguide configured for wavelength division multiplexing (WDM) (the integrated circuit 100 is described as a wavelength division multiplexer and demultiplexer [0038]) an optical signal (“input optical beam” LS; [0041]; FIG. 1), the optical waveguide comprising: a first port (IN1; FIG. 5A and FIG. 1); a first stage (110) comprising a first cascaded Mach-Zehnder interferometer (MZI) filter (“first-stage MZI structure” S11; [0052] discloses that filter S11 may be the structure shown in FIG. 5A) and a first pair of cascaded MZI filters (“second-stage MZI structures” S12A, S12B; [0052] discloses that filters S12A and S12B may be the structure shown in FIG. 5A); wherein the first cascaded MZI filter is coupled to the first port (IN1 becomes the port where optical signal LS is input to the device in FIG. 1); wherein the first pair of cascaded MZI filters are coupled to the first cascaded MZI filter ([0054]; FIG. 1), the first cascaded MZI filter comprising a taper ([0046] discloses that both arms of the optical waveguide may comprises “tapered waveguide sections” with lengths T1/2 and T2/2, respectively; see also FIGs. 4A, 5A) with a width increasing along a length of the taper (a changing width along a certain length is understood to be inherent to a structure described as a “taper”); the taper transitioning between a thinner section and a thicker section of the optical waveguide and having a width that increases along a first length (fig. 4A); a second stage (121 and 122; FIG. 1) comprising: a second cascaded MZI filter (“first-stage MZI structure” S21 in optical waveguide 121; [0052] discloses that filter S21 may be the structure shown in FIG. 5B) and a second pair of cascaded MZI filters (“second-stage MZI structures” S22A, S22B in optical waveguide 121; [0052] discloses that filters S22A and S22B may be the structure shown in FIG. 5B); wherein the second cascaded MZI filter is coupled to a first of the first pair of cascaded MZI filters (S12A; FIG. 1); wherein the second pair of cascaded MZI filters are coupled to the second cascaded MZI filter (FIG. 1); wherein a first of the second pair of cascaded MZI filters (S22A) comprises a first passband (“channel” CH1; [0054]-[0055]); wherein a second of the second pair of cascaded MZI filters (S22B) comprises a second passband (“channel” CH2); and a third cascaded MZI filter (S21 in optical waveguide 122) and a third pair of cascaded MZI filters (S22A and S22B in optical waveguide 122); wherein the third cascaded MZI filter is coupled to a second of the first pair of cascaded MZI filters (S12B; FIG. 1); wherein the third pair of cascaded MZI filters are coupled to the third cascaded MZI filter (FIG. 1); wherein a first of the third pair of cascaded MZI filters (S22A) comprises a third passband (“channel” CH3); wherein a second of the third pair of MZI filters (S22B) comprises a fourth passband (“channel” CH4); and a plurality of second ports (OUT1 and OUT2; FIG. 5A and FIG. 1); wherein the plurality of second ports comprises four ports (CH1-CH4; FIG. 1).
Hung does not teach that the taper is a nonlinear taper having a convex shape and having a second length being selected to reduce optical loss.
Seyringer teaches an optical waveguide with a nonlinear taper (22) for an optical multiplexer/demultiplexer (fig. 1). The nonlinear taper (22) having a convex shape with a width that increases nonlinearly along a first length (between BP1 and BP2), transitioning between a thinner section (21) and a thicker section (23), and a second length (23 section; English Translation, p. 4, 1st paragraph).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the instant application to use Seyringer’s nonlinear taper in Hung’s device since such modification would have been an obvious design variation, well within the ordinary skill in the art, since it has been held that the selection of a known material based on its suitability for its intended use such as audio application. In re Leshin, 125 USPQ 146.
Hung/Seyringer does not explicitly teach that the first cascaded MZI filter and the first pair of cascaded MZI filters comprises fourth-order MZI filters. In the integrated circuit 100 of Hung, the first cascaded MZI filter (S11) and the first pair of cascaded MZI filters (S12A, S12B) are each third-order (“three-stage”; [0052] – the examiner notes that throughout, Hung uses the word “stage” to mean both “stage” as used in the instant claim and also “order” as used in the instant claim) MZI filters (see FIG. 5A). Hung does teach that, in general, a higher-order filter (an “MZI structure with more stages”) exhibits lower optical crosstalk among different channels ([0051]).
Fincato teaches an integrated circuit (“interleaver-based wavelength demultiplexer”; [0047]; FIG. 15B) which comprises a series of cascaded MZI filters (“interleaver”; [0047]; FIG. 16) and is configured for WDM. Fincato further teaches that each stage (interleaver) in the integrated circuit may comprise a fourth-order MZI filter (see FIG. 16 – sections 1602, 1604, 1606, 1608 taken together comprise a fourth-order MZI filter).
Therefore, before the effective filing date of the instant application, it would have been obvious to one of ordinary skill in the art, based on the teachings of Fincato, to use a fourth-order MZI filter for the first cascaded MZI filter and the first pair of cascaded MZI filters in the device of Hung. One of ordinary skill in the art would have been motivated to do so based on the teachings of Hung that higher-order filters may be desirable to reduce optical crosstalk. Fincato teaches that fourth-order filters in particular are known in the art, and incorporating the teachings of Fincato into the device of Hung would have involved at most a duplication of one of the constituent MZI filters in each cascaded MZI filter of Hung and would have produced the predictable result of lowering the optical crosstalk (Hung [0051]; FIG. 6). It has been held that duplication of parts in the absence of a new and unexpected result is obvious. In re Harza, 274 F.2d 669, 124 USPQ 378 (CCPA 1960). See MPEP 2144.04(VI)(B).
Hung/Seyringer/Fincato also does not explicitly teach that the second cascaded MZI filter, the second pair of cascaded MZI filters, the third cascaded MZI filter, and the third pair of cascaded MZI filters comprises third-order MZI filters. In the integrated circuit 100 of Hung, the second and third cascaded MZI filters (S22) and the second and third pair of cascaded MZI filters (S22A, S22B) are each second-order (“two-stage”; [0052]) MZI filters (see FIG. 5B). However, Hung does teach that, in general, a higher-order filter (an “MZI structure with more stages”) exhibits lower optical crosstalk among different channels ([0051]), and Hung teaches that third-order filters are known and suitable for use in the first stage of the integrated circuit 100. Hung also teaches that the device taught therein may be modified according to design requirements ([0057]).
Therefore, before the effective filing date of the instant application, it would have been obvious to one of ordinary skill in the art, based on the additional teachings of Hung, to use a third-order MZI filter for the second cascaded MZI filter, the second pair of cascaded MZI filters, the third cascaded MZI filter, and the third pair of cascaded MZI filters, thereby rendering obvious all of the structural limitations of instant claim 19. One of ordinary skill in the art would have been motivated to do so based on the teachings of Hung that higher-order filters may be desirable to reduce optical crosstalk. Using a third-order filter for the second and third cascaded MZI filters and the second and third pairs of cascaded MZI filters would have involved at most a duplication of one of the constituent MZI filters in each cascaded MZI filter of Hung and would have produced the predictable result of lowering the optical crosstalk (Hung [0051]; FIG. 6). It has been held that duplication of parts in the absence of a new and unexpected result is obvious. In re Harza, 274 F.2d 669, 124 USPQ 378 (CCPA 1960). See MPEP 2144.04(VI)(B).
The examiner notes that the additional limitation of claim 19 “the nonlinear taper reducing the transition length between phase sections and minimizing signal loss” is a property of a nonlinear taper which is presumed to be inherent to the structure of the device of Hung in combination with the teachings of Seyringer and Fincato. When a structure recited in a reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent. See MPEP 2112.01. The patentability of a product depends only on the claimed structural limitations of the product. Hung in view of Seyringer and Fincato teaches an integrated circuit and a nonlinear taper which are substantially identical to the claimed invention, therefore the claimed property is presumed to be inherent. Seyringer further discloses the taper are designed for reducing transition/crosswalk loss (English Translation, p. 5, 2nd to last paragraph). The additional claimed property of “reducing the transition length between phase sections” is understood to be inherent to all tapers in optical waveguide structures. The burden is on the applicant to show that the prior art device does not possess the claimed properties or is not capable of these functional characteristics. See MPEP 2112.01.
Claim(s) 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hung in view of Seyringer and Fincato as applied to claim 19 above, and further in view of Arai et al. US 2003/0091071 A1.
Regarding claim 20, modified Hung 19 does not teach that the first cascaded MZI filter (S11) is interleaved with the first pair of cascaded MZI filters (S12A, S12B) and therefore does not teach the remaining limitations of the claim. Hung does teach that “device footprint” is a consideration when forming the cascading MZI filters ([0051]).
Arai teaches an integrated circuit configured for WDM (“waveguide-type optical multiplexer/demultiplexer”; [0060]; FIG. 13) comprising a first cascaded MZI filter (“first optical multiplexer/demultiplexer circuit” 2a) and a first pair of cascaded MZI filters (“second/third optical multiplexer/demultiplexer circuits” 2b, 2c), wherein the first cascaded MZI filter is interleaved with the first pair of cascaded MZI filters (see FIG. 13) for reducing a footprint of the optical waveguide on the substrate ([0060]: “According to this embodiment, compactness of the whole constitution is advantageously obtained”); wherein the first pair of cascaded MZI filters are interleaved by folding and an offset (see FIG. 13 – the first pair of cascaded MZI are folded such that the direction which the optical signal travels is reversed and are offset from first cascaded MZI filter and from each other); wherein the first pair of cascaded MZI filters are folded backwards from the first cascaded MZI filter toward the first port (see FIG. 13); wherein each of the first pair of cascaded MZI filters are offset from the first cascaded MZI filter by a distance (see FIG. 13). As taught by Arai, the folding structure disclosed therein advantageously reduces the device footprint and improves “compactness” ([0060]).
Therefore, before the effective filing date of the instant application, it would have been obvious to one of ordinary skill in the art, based on the teachings of Arai, to configure the first cascaded MZI filter and first pair of cascaded MZI filters of Hung/Seyringer/Fincato wherein the first cascaded MZI filter is interleaved with the first pair of cascaded MZI filters for reducing a footprint of the optical waveguide on the substrate; wherein the first pair of cascaded MZI filters are interleaved by folding and an offset; wherein the first pair of cascaded MZI filters are folded backwards from the first cascaded MZI filter toward the first port; wherein each of the first pair of cascaded MZI filters are offset from the first cascaded MZI filter by a distance, thereby rendering obvious instant claim 20. One of ordinary skill in the art would have been motivated to do so based on the teachings of Hung that device footprint (and specifically, keeping the device footprint small) is a concern when manufacturing integrated MZ devices ([0051]) and based on the additional teachings of Arai that the folding technique disclosed therein is one way to reduce the device footprint while still allowing for a cascaded arrangement of MZI filters (Arai [0060]). Use of a known technique (e.g., interleaving cascaded MZI filters by folding and an offset) to improve (e.g., to reduce the footprint of) similar devices (methods, or products) in the same way has been held to be obvious. KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Ahmadvand et al. (US 6754411 B2) and Huang et al. (US 6160932 A) disclose multi-stage WDM
Li et al. (CN 110426788 B) discloses WDM having cascaded MZ with waveguide taper
Lee et al. (US 10935726 B1) and Shin et al. (US 20110150388 A1) discloses MZI having arms with taper
Seyringer et al. (DE 10145277 B4) discloses nonlinear taper waveguide
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Uyen-Chau N. Le whose telephone number is (571)272-2397. The examiner can normally be reached Monday-Friday, 9:00am-5:30pm.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Kiesha R. Bryant can be reached at (571) 272-3606. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/UYEN CHAU N LE/Supervisory Patent Examiner, Art Unit 2874
Prosecution Insights