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 .
DETAILED OFFICE ACTION
Claim Status
Claims 1-13 are pending in this application and are under examination in this Office Action. No claims have been allowed.
Drawings
The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims in a clear and accurate manner. Therefore, the claimed limitation within claim 1 of a “photodiode” is not accurately shown within the drawings because element 15 is labeled “phtodiode” in FIG. 1 and FIG. 3 rather than “photodiode.” The drawings must be corrected so that the labeling of element 15 is consistent with the specification and claims. The feature must be properly shown or labeled in the drawings, or the inconsistency otherwise corrected. No new matter should be entered.
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms.
Claims 11, 12 and 13 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 2 and 3, respectively, of U.S. Patent No. 12,388,531. Although the claims at issue are not identical, they are not patentably distinct from each other because of the following similarity of the claim limitations:
The present application identifies Global Technology Inc., Ningbo (CN), as applicant. U.S. Patent No. 12,388,531 identifies Global Technology Inc., Ningbo (CN), as applicant and assignee. Accordingly, the present application and the reference patent appear commonly owned. The present application also names Fan Yang and Qikun Huang among the inventors, and U.S. Patent No. 12,388,531 also names Fan Yang and Qikun Huang among the inventors.
Present Application
U.S. Patent No. 12,388,531
As per claim 11, The optical transmission system according to claim 6, wherein the lithium niobate modulator comprises: an optical splitting element coupled to the laser, and the optical splitting element configured to split at least a part of the initial optical signal to generate two optical splitting signals; two optical splitting paths coupled to the optical splitting element, and the two optical splitting paths configured to transmit the two optical splitting signals; a radio frequency signal channel disposed in parallel between the two optical splitting paths, and the radio frequency signal channel configured to transmit the first electrical signal; two ground channels disposed in parallel with the radio frequency signal channel and coupled to the radio frequency signal channel, and the two ground channels configured to be grounded; and an optical combining element coupled to the two optical splitting paths, and the optical combining element configured to combine the two optical splitting signals and generate the modulated optical signal, wherein, the radio frequency signal channel and the two ground channels are configured to modulate the two optical splitting signals in accordance with the first electrical signal.
As per claim 1, An optical transmission device based on lithium niobate modulation method, comprising: a laser configured to generate an initial optical signal; and a lithium niobate modulator comprising: an input optical fiber connected to the laser and configured to receive the initial optical signal; a first beam splitter connected to the input optical fiber and configured to split at least a part of the initial optical signal to generate two first optical splitting signals; two first optical splitting paths connected to the first beam splitter and configured to transmit the two first optical splitting signals; a first radio-frequency signal channel disposed in parallel between the two first optical splitting paths and configured to transmit a first radio-frequency modulation signal; two first ground channels disposed in parallel with the first radio-frequency signal channel and connected to the first radio-frequency signal channel and configured to be grounded; a first beam combiner connected to the two first optical splitting paths and configured to combine the two first optical splitting signals to generate a first optical modulation signal; and a first output optical fiber connected to the first beam combiner and configured to output the first optical modulation signal, wherein the first radio-frequency signal channel and the two first ground channels are used in modulation of the two first optical splitting signals in accordance with the first radio-frequency modulation signal.
The features of claim 11 of the current application that are not present in claim 1 of U.S. Patent No. 12,388,531 are:
"an optical fiber coupled to the lithium niobate modulator with one end, and the optical fiber configured to transmit the modulated optical signal; a photodiode coupled to another end of the optical fiber, and the photodiode configured to convert the modulated optical signal into a second electrical signal; an electronic dispersion compensation chip coupled to the photodiode, and the electronic dispersion compensation chip configured to compensate the electronic dispersion in the second electrical signal to generate a third electrical signal; and wherein the modulated optical signal is a first modulated optical signal, and the signal generator is further configured to generate a fourth electrical signal, a data transmission rate of the fourth electrical signal is less than the data transmission rate of the first electrical signal, and the lithium niobate modulator is further configured to modulate the initial optical signal with the fourth electrical signal to generate a second modulated optical signal."
However, U.S. Patent No. 12,388,531 itself further teaches a second optical modulation path. Specifically, claim 4 teaches a second beam splitter connected to the input optical fiber and configured to split another part of the initial optical signal to generate two second optical splitting signals; two second optical splitting paths; a second radio-frequency signal channel; a second ground channel; a second beam combiner; and a second output optical fiber, such that a second optical modulation signal is generated and output. Further, claim 6 teaches another second ground channel disposed in parallel with the second radio-frequency signal channel and connected to the second radio-frequency signal channel, wherein the second radio-frequency signal channel and two second ground channels are used in modulation of the two second optical splitting signals.
Further, in an analogous art, Elahmadi et al. (US 2017/0054507 A1) teaches optical transceiver components including receiver-side optical-to-electrical conversion and electronic dispersion compensation circuitry communicatively coupled to transceiver components, thereby teaching the photodiode / receiver and electronic dispersion compensation environment.
Further, in an analogous art, U.S. Patent Publication No. 2005/0169585 A1 teaches operation of optical / electrical transceiver circuitry at a lower data rate and teaches that signal-degradation compensation may be omitted for data rates lower than about 10 Gb/s, thereby evidencing a lower-rate electrical signal path distinct from a higher-rate path.
Based on the above findings, it would have been obvious to one of ordinary skill before the effective filing date of the invention to add the receiver-side optical fiber / photodiode / electronic dispersion compensation arrangement and the lower-rate additional signal path taught by Elahmadi et al. and U.S. Patent Publication No. 2005/0169585 A1 to the optical transmission device taught by claim 1, and further the second optical modulation path taught by claims 4 and 6, of U.S. Patent No. 12,388,531 as no more than the predictable use of prior-art elements according to their established functions.
Present Application
U.S. Patent No. 12,388,531
As per claim 12, The optical transmission system according to claim 11, wherein the lithium niobate modulator further comprises a set of hot electrodes disposed at the two optical splitting paths, and the set of hot electrodes is configured to implement phase modulation on the two optical splitting signals.
As per claim 2, The optical transmission device based on lithium niobate modulation method of claim 1, wherein the lithium niobate modulator further comprises a set of hot electrode which is disposed at the two first optical splitting paths and configured to modulate the two first optical splitting signals.
The feature of claim 12 of the current application that is not expressly present in claim 2 of the U.S. Patent No. 12,388,531 is that the set of hot electrodes is configured to implement phase modulation on the two optical splitting signals.
However, in an analogous art, U.S. Patent No. 12,413,311 teaches a hot electrode directly connected to the optical splitting path and configured to additionally modulate the optical splitting signal (such as the phase of the optical signal). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to implement phase modulation using the hot electrodes of claim 2 of U.S. Patent No. 12,388,531.
Present Application
U.S. Patent No. 12,388,531
As per claim 13, The optical transmission system according to claim 11, wherein the lithium niobate modulator further comprises a terminating resistor disposed between the radio frequency signal channel and the two ground channels, and the terminating resistor is coupled to the radio frequency signal channel and the two ground channels.
As per claim 3, The optical transmission device based on lithium niobate modulation method of claim 1, wherein the lithium niobate modulator further comprises a terminal resistor disposed between the first radio-frequency signal channel and the two first ground channels and connected to the first radio-frequency signal channel and the two first ground channels.
Accordingly, claim 13 is not patentably distinct from claim 3 of U.S. Patent No. 12,388,531.
Claim Rejections - 35 USC § 112(a)
The following is a quotation of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
Claims 11, 12 and 13 are rejected under 35 U.S.C. 112(a) because the originally filed specification, including the drawings, does not reasonably convey to one of ordinary skill in the art that applicant was in possession of the presently claimed subject matter.
Regarding claim 11,
Claim 11 recites ("a radio frequency signal channel disposed in parallel between the two optical splitting paths," "two ground channels disposed in parallel with the radio frequency signal channel," and "wherein, the radio frequency signal channel and the two ground channels are configured to modulate the two optical splitting signals in accordance with the first electrical signal.")
The specification does describe the internal structure of the lithium niobate modulator. In particular, the specification states that "lithium niobate modulator 13 includes an input optical fiber, an optical splitting element 131, two optical splitting paths 132, two radio frequency signal channels 133, three ground channels 134, an optical combining element 135 and an output optical fiber connector 136" and further states that "One radio frequency signal channel 133 and the two adjacent ground channels 134 may be configured to modulate one of the two optical splitting signals with the first electrical signal, while the other optical splitting signal might be modulated using another radio frequency channel 133" ([0022], Fig. 2).
However, the originally filed disclosure is directed to a modulator structure having two radio frequency signal channels and three ground channels, with one radio frequency signal channel and its adjacent ground channels modulating one optical splitting signal while another radio frequency signal channel is used for the other optical splitting signal. Claim 11, by contrast, is drafted to require a singular radio frequency signal channel and two ground channels that are configured to modulate the two optical splitting signals. Those are materially different arrangements. The originally filed specification therefore does not reasonably convey possession of the full scope of the modulator relationship now recited in claim 11. Accordingly, claim 11 is rejected under 35 U.S.C. 112(a).
Regarding claim 12,
Claim 12 depends from claim 11 and therefore incorporates the unsupported subject matter discussed above. Claim 12 additionally recites ("the lithium niobate modulator further comprises a set of hot electrodes disposed at the two optical splitting paths, and the set of hot electrodes is configured to implement phase modulation on the two optical splitting signals.")
The specification does describe hot electrodes. Specifically, the specification states that "the lithium niobate modulator 13 may also include a set of hot electrodes 137" and that "The hot electrodes 137 are disposed in the two optical splitting paths 132 and configured to implement phase modulation to the two split optical signals" ([0024], Fig. 2).
However, although the additional hot-electrode limitation is described, claim 12 still includes the unsupported claim 11 subject matter requiring the singular radio frequency signal channel and two ground channels to modulate the two optical splitting signals. The added disclosure of hot electrodes does not cure the written-description deficiency already present in the base claim. Accordingly, claim 12 is rejected under 35 U.S.C. 112(a).
Regarding claim 13,
Claim 13 recites ("a terminating resistor disposed between the radio frequency signal channel and the two ground channels, and the terminating resistor is coupled to the radio frequency signal channel and the two ground channels.")
The specification does describe a terminating resistor. In particular, the specification states that "a terminating resistor 138 may be provided between the radio frequency signal channel 133 and the ground channel 134 as a load, when connecting to the radio frequency signal channel 133 and the ground channel 134" ([0023], Fig. 2).
However, the originally filed disclosure describes a terminating resistor provided between the radio frequency signal channel and the ground channel in the singular. Claim 13 is drafted more broadly and differently, requiring a terminating resistor disposed between the radio frequency signal channel and the two ground channels and coupled to the radio frequency signal channel and the two ground channels. The originally filed specification does not clearly describe that claimed resistor arrangement. Accordingly, claim 13 is rejected under 35 U.S.C. 112(a).
Accordingly, claims 11-13 are rejected under 35 U.S.C. 112(a).
Claim Rejections - 35 USC § 112(b)
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION. —The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 9 and 10 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention.
Regarding claim 9,
Claim 9 recites ("the electronic dispersion compensation chip is further configured not to implement phase compensation on the fourth electrical signal when the data transmission rate of the fourth electrical signal is less than or equal to 10Gbps.")
Claim 6, from which claim 9 depends, defines the "fourth electrical signal" as a signal generated by the signal generator and used by the lithium niobate modulator to generate the second modulated optical signal. Thus, claim 6 places the fourth electrical signal at the transmitting side of the system before optical transmission. Claim 9, however, attributes to the electronic dispersion compensation chip a function of not implementing phase compensation on that same fourth electrical signal, even though the electronic dispersion compensation chip is downstream of the photodiode at the receiving side of the system.
The specification does not resolve that ambiguity. In particular, the specification states that "when the electronic dispersion compensation chip 16 receives an electrical signal with a data transmission rate of 10 Gbps, additional dispersion compensation may not be performed on the electrical signal" ([0032]). The specification also states that when the radio frequency signal channel receives a 10 Gbps electrical signal, "the optical signal is transmitted to the photodiode 15, with the corresponding electrical signal transmitted to the electronic dispersion compensation chip 16 and passing through the bypass signal line" ([0034], Fig. 3). Thus, the specification refers to an electrical signal received at the electronic dispersion compensation chip after photoelectric conversion, not necessarily the originally generated "fourth electrical signal" of claim 6. Because it is unclear whether claim 9 refers to the transmitter-side fourth electrical signal or the receiver-side electrical signal corresponding to the received optical signal, the metes and bounds of claim 9 are not reasonably certain. Accordingly, claim 9 is indefinite under 35 U.S.C. 112(b).
Regarding claim 10,
Claim 10 recites ("wherein a bypass signal line is provided inside the electronic dispersion compensation chip, and when the electronic dispersion compensation chip receives the fourth electrical signal, the electronic dispersion compensation chip switches the fourth electrical signal to pass through the bypass signal line.")
As discussed above with respect to claim 9, claim 6 defines the "fourth electrical signal" as the signal generated by the signal generator and used by the lithium niobate modulator at the transmitting side. Claim 10, however, states that the electronic dispersion compensation chip receives that fourth electrical signal and switches that fourth electrical signal through the bypass signal line. The claim therefore uses the same term for a transmitter-side signal and for a signal allegedly received by a receiver-side
component after optical transmission, without making clear whether those are the same signal, a corresponding converted signal, or some other signal.
The specification again uses different language. Specifically, the specification states that "an additional bypass signal line may be provided inside the electronic dispersion compensation chip 16" ([0033]) and further states that when the radio frequency signal channel receives a 10 Gbps electrical signal, "the optical signal is transmitted to the photodiode 15, with the corresponding electrical signal transmitted to the electronic dispersion compensation chip 16 and passing through the bypass signal line" ([0034], Fig. 3). The originally filed disclosure therefore refers to the corresponding electrical signal transmitted from the photodiode to the electronic dispersion compensation chip, rather than clearly stating that the chip receives the originally generated fourth electrical signal itself. Because claim 10 does not clearly identify what signal is received and switched by the electronic dispersion compensation chip, the scope of claim 10 is indefinite. Accordingly, claim 10 is rejected under 35 U.S.C. 112(b).
Accordingly, claims 9 and 10 are indefinite under 35 U.S.C. 112(b).
Claim Rejections – 35 U.S.C. § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for the 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.
As reiterated by the Supreme Court in KSR, and as set forth in MPEP 2141 (R-01.2024), II, the factual inquiries of Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), applied for establishing a background for determining obviousness under 35 U.S.C. §103, are summarized as follows:
Determining the scope and content of the prior art;
Ascertaining the differences between the prior art and the claims at issue;
Resolving the level of ordinary skill in the pertinent art; and
Considering objective evidence indicative of obviousness or non-obviousness, if present.
This application currently names joint inventors. In considering patentability of the claims, the examiner presumes that the subject matter disclosed in the prior art was created by another (i.e., not by the inventive entity) unless proven otherwise. Applicant is advised of the obligation under 37 C.F.R. § 1.56 to point out the inventor and effective filing dates of each claim, and any evidence of common ownership/assignment as of the effective filing date, so that the examiner may properly consider the applicability of 35 U.S.C. § 102(b)(2)(C) for any potential 35 U.S.C. § 102(a)(2) prior art against the claimed invention(s).
Claim 1 is rejected under 35 U.S.C. § 103 as being unpatentable over Gnauck et al. (US5303079) in view of Jiang et al. (US20110052216A1).
Claim 1
Regarding claim 1, Gnauck teaches the basic optical transmission architecture. Specifically, Gnauck teaches “A Lightwave transmission system … including a transmitter, a receiver, and a transmission medium connecting the transmitter to the receiver. The transmitter includes laser 10 … external modulator 16, controller 24, and data source 22 … [and] the transmission medium is shown as lengths of optical fiber 19” [Gnauck. cols. 3-4].
Gnauck therefore teaches a laser configured to generate an initial optical signal, a signal generator/data source that provides electrical information, a modulator in the transmitter, and an optical fiber transmission medium coupled between the transmitter and the receiver.
Gnauck further teaches that “Controller 24 receives a digital data signal from data source 22 … [and] generates modulation control signals output to external modulator 16 … so that the data from data source 22 is properly modulated onto the optical signals” [Gnauck. cols. 3-4]. Thus, Gnauck teaches the claimed signal generator configured to generate a first electrical signal and a lithium niobate external modulator configured to modulate the initial optical signal with that electrical signal to generate a modulated optical signal.
Gnauck also discloses the lithium niobate Mach-Zehnder structure in greater detail, teaching that an “input Y-branch couples the optical signal … into both coplanar strip waveguides 163 and 164 while output Y-branch couples the optical signals … into a single waveguide 170” and that “the waveguides were produced by diffusion of titanium z-cut LiNbO3” [Gnauck. cols. 5-6].
This further confirms that Gnauck’s external modulator is a lithium niobate modulator coupled to the laser and configured to output a modulated optical signal into the fiber link.
Gnauck does not expressly disclose the downstream photodiode and electronic dispersion compensation chip as recited. However, within analogous art, Jiang teaches that the transmitter-side electrical signal is supplied to an optical interface “suitable to generate an optical signal to be launched into an optical communication link [such as an optical fiber]” and that on the receiver side “the optical signal is converted … to an electrical signal (e.g., using a photo-detector device such as a photo-diode)” [Jiang, ¶ ¶ [0041] - [0061]].
Jiang further teaches that “the now-generated electrical signal can be provided to an analog to digital converter (ADC) circuitry … and subsequently to an electronic dispersion compensation (EDC) circuitry … for … dispersion compensation” [Jiang, ¶ [0062]].
Thus, Jiang expressly teaches the missing receiving-side photodiode/electrical conversion and electronic dispersion compensation chip downstream of the photodiode.
Accordingly, the combination of Gnauck and Jiang teaches every limitation of claim 1: a laser configured to generate an initial optical signal; a signal generator configured to generate a first electrical signal; a lithium niobate modulator coupled to the laser and the signal generator and configured to modulate the initial optical signal with the first electrical signal; an optical fiber coupled to the lithium niobate modulator; a photodiode configured to convert the modulated optical signal into a second electrical signal; and an electronic dispersion compensation chip coupled to the photodiode and configured to compensate dispersion in the received electrical signal.
One of ordinary skill in the art would have been motivated to combine Gnauck with Jiang because both references address optical communication systems that generate an optical signal at a transmitter, transmit that signal over optical fiber, convert the received optical signal back into the electrical domain at a receiver, and address transmission impairments introduced by the fiber and receiver hardware. Gnauck already teaches the exact type of external lithium niobate modulation architecture used to impress the electrical data onto the optical carrier, while Jiang expressly teaches that once the optical signal arrives at the receiver it is conventional to use a photo-detector/photo-diode and to provide the resulting electrical signal to EDC circuitry for dispersion compensation. Combining Gnauck’s known external lithium niobate transmitter with Jiang’s known photodiode-plus-EDC receiver would have amounted to no more than using familiar prior-art elements according to their established functions in the expected transmitter fiber receiver chain. Such a combination would have predictably improved long reach optical transmission performance by mitigating dispersion electrically at the receiver while retaining the modulation advantages of Gnauck’s lithium niobate transmitter. Nothing in either reference teaches away from that combination, and the resulting system would merely reflect the ordinary design choice of implementing a known EDC receiver with a known externally modulated fiber-optic transmitter.
Claim 2 is rejected under 35 U.S.C. § 103 as being unpatentable over Gnauck et al. in view of Jiang et al., and further in view of Yao et al. (US10142024B2).
Claim 2
With respect to claim 2, all limitations of claim 1 are taught by Gnauck and Jiang, except that Gnauck and Jiang do not expressly specify that the first electrical signal has a data transmission rate greater than or equal to 25 Gbps. However, within analogous art, Yao teaches that “the graph 300 demonstrates experimental results for a 25 Gb/s PON employing NRZ modulation using a 10 Gb/s EML and APD” [Yao, col. 5-6].
Yao therefore teaches operation of an optical communication system at 25 Gb/s, and further associates that operating point with an APD-based receiver and electronic equalization circuitry in the receiver.
Accordingly, claim 2 would have been obvious over Gnauck in view of Jiang and further in view of Yao.
One of ordinary skill in the art would have been motivated to adopt a 25 Gb/s electrical data rate in the combined Gnauck/Jiang system because the references are directed to scalable optical communication hardware, and Yao shows that 25 Gb/s was a known and commercially meaningful operating point for such systems. Increasing the data rate of the electrical drive signal supplied to an external optical modulator was a routine design objective driven by bandwidth demand and network evolution. A person of ordinary skill would have expected Gnauck’s externally modulated architecture to be adaptable to higher data rates using known high-speed components, and Jiang ’s receiver-side EDC teaching would have reinforced that such higher-rate links could be supported by digital dispersion compensation after photo-detection. Thus, specifying a first electrical signal rate of at least 25 Gb/s would have been an obvious optimization of a known optical transmission architecture to achieve a predictable increase in throughput.
Claims 3 and 5 are rejected under 35 U.S.C. § 103 as being unpatentable over Gnauck et al. in view of Jiang et al., and further in view of Yao et al., and further in view of Liao et al. (CN214626994U) and Elahmadi et al. (US20170054507A1).
Claim 3
With respect to claim 3, all limitations of claim 2 are taught by Gnauck, Jiang and Yao except that base combination does not expressly state that the optical fiber has a length greater than or equal to 40 km. However, Liao teaches that “The 25GBASE-ER optical module is mainly used for medium and long-distance transmission, supports the transmission distance of 40KM” [Liao, Background]
Additionally, Elahmadi also teaches 10G-class pluggable optical transceivers used for links that extend to 40 km in standardized MSA environments “[0059] The X2 204 MSA defines a small form-factor 10 Gbps optical fiber optic transceiver optimized for 802.3ae Ethernet, ANSI/ITUT OC192/STM-64 SONET/SDH inter faces, ITU-T G.709, OIF OC192 VSR, INCITS/ANSI 10 GFC (10 Gigabit Fiber Channel) and other 10 Gigabit applications. X2 204 is physically smaller than XENPAK 202 but maintains the same electrical I/O specification defined by the XENPAK 202 MSA and continues to provide robust thermal performance and electromagnetic shielding. X2 204 uses the same 70-pin electrical connectors as XEN PAK 202 supporting four wire XAUI (10-gigabit attachment unit interface). X2204 supports an input signal of G.709, but does not Support framing a non-G.709 signal internal to the optical transceiver and also does not support FEC and optical layer OAM&P. The X2 204 MSA is available at www.x2msa.org/MSA.asp and is hereby incorporate by ref CCC. [0060] The XFP (10 Gigabit Small Form Factor Optical) 206 is a hot-swappable, protocol independent optical transceiver, typically operating at 1310 nm or 1550 nm, for 10 Gigabit SONET/SDH, Fiber Channel, Gigabit Ethernet and other applications. The XFP 206 MSA is available from www.Xfpmsa.org and is hereby incorporated by reference. The XFP206 MSA defines a specification for a module, cage hardware, and IC interfaces for a 10 Gbps hot optical module converting serial electrical signals to external serial optical or electrical signals. The technology is intended to be flexible enough to support bit rates between 9.95 Gbps and 11.1 Gbps for services such as OC-192/STM-64, 10 G Fiber Channel, G.709, and 10 G Ethernet. XFP 206 supports native G.709 signals, but does not support the ability to frame a non-G.709 signal into a G.709 wrapper with FEC and OAM&P internal to the XFP 206 module. Currently, these features are done external to the XFP206 module and a G.709 signal is sent to the XFP206 module for optical transmission. XFP-E (not shown in FIG. 2) is an extension of the XFP206 MSA for ultra-long haul DWDM applications and tunable optical transmitters. [0061] XPAK (not shown in FIG. 2) is a reduced-sized, optical 10 Gigabit Ethernet (GbE) module customized for enterprise, storage area network (SAN), and Switching center market segment applications. The XPAK specifications define mechanical, thermal, and electromagnetic interference (EMI) mitigation features of the form factor, as well as reference 10-GbE optical and XENPAK 202 MSA electrical specifications. XPAK offers higher density and better power efficiency than XENPAK 202 and offers 10 GbE links up to 10 km and eventually 40 km. The SFP+ (not shown in FIG.2) MSA is a specification for an optical, hot-swappable optical interface for SONET/SDH, Fiber Channel, Gigabit Ethernet, and other applications. SFP+ is designed for up to 80 km reach and supports a full-range of applications. SFP+ is similar in size and power with the XFP206 specification, and similarly accepts a serial electrical input” [Elahmadi, ¶¶ [0059] - [0061]]
These teachings show that 40 km reach was a known design target for optical module implementations of the type at issue.
One of ordinary skill in the art would have been motivated to configure the optical fiber span in the combined system to be 40 km or greater because the art expressly recognized medium- and long-reach optical modules, including 40 km class systems, as important deployment targets. Gnauck already describes a Lightwave transmission system spanning a distance between transmitter and receiver through lengths of optical fiber and optical amplifiers, and Jiang ’s EDC teaching is specifically directed to compensating dispersion that accumulates during transmission through the optical channel. The known benefit of using EDC is particularly relevant as span length increases, because longer fiber links incur greater dispersion penalties. Therefore, extending the fiber length to 40 km or greater in the combined architecture would have been a predictable implementation choice made to satisfy known reach requirements while relying on familiar compensation techniques to preserve signal quality.
Claim 5
With respect to claim 5, all limitations of claim 1 are taught by Gnauck and Jiang. However, within analogous art, Yao likewise teaches an APD-based receiver and states that “the receiver 225 comprises … an APD linear BM RX 230” and that “The APD linear BM RX 230 converts the optical signals into electrical signals” [Yao, col. 5-6].
Additionally, Elahmadi expressly teaches that “The RX can include a PIN or avalanche photodiode (APD)” “[0129] Referring to FIG.22, a table 2350 illustrates exemplary specifications for the SFP transceiver 2300 according to an exemplary embodiment. The SFP transceiver 2300 conforms to the SFP MSA form factor, and can support bit rates from 155 Mb/s to 4.25 Gb/s which corresponds to OC-3 to 4 Gigabit Fibre Channel. The Tx can be any type including 1550 nm gray (uncooled), CWDM (uncooled), and DWDM. The RX can include a PIN or avalanche photo diode (APD). The SFP transceiver 2300 has varying amounts of dispersion tolerance from 120 km to 360 km and associated link budgets from 20 dB to 32 dB. As described herein, the SFP transceiver 2300 can be used in any device capable of utilizing an SFP-compliant transceiver including Ethernet switches, IP routers, MSPPs, SAN directors, CPE demarcation, and the like” [Elahmadi, ¶ [0129]].
These teachings expressly satisfy the claim requirement that the photodiode is an avalanche photodiode.
One of ordinary skill in the art would have been motivated to use an APD in the receiver of the combined system because APDs were well-known high-sensitivity photodiodes used in optical receivers, particularly in longer-reach links and in systems operating at elevated data rates where receiver sensitivity is important. Jiang already teaches photo-diode based optical-to-electrical conversion followed by EDC, and Elahmadi and Yao each show that APD implementations were standard and beneficial in analogous optical transceiver environments. Substituting one known photodiode type for another to obtain the known sensitivity benefits of an APD would have been a routine design choice yielding predictable results. The modification would not have altered the principle of operation of the combined Gnauck/Jiang system; it would simply use a known receiver component option expressly identified in the art.
Claim 4 is rejected under 35 U.S.C. § 103 as being unpatentable over Gnauck et al. in view of Jiang et al., and further in view of Coleman et al. (US8804787B1).
Claim 4
With respect to claim 4, all limitations of claim 1 are taught by Gnauck and Jiang except that base combination does not expressly require that the laser is a laser diode having a linewidth less than 200 kHz. However, Coleman teaches a semiconductor laser system with “a narrow laser linewidth (e.g., <10 kHz)” and further explains that “the back-reflection provides enough coherent feedback to narrow the laser linewidth from several hundred kHz to ~<10 kHz” [Coleman, col. 5-6]
A laser diode linewidth below 10 kHz necessarily teaches a linewidth below the claimed 200 kHz threshold, and the reference expressly discusses semiconductor laser implementation.
One of ordinary skill in the art would have been motivated to select a narrow-linewidth laser diode, including one having linewidth less than 200 kHz, for the combined optical transmission system because the art understood that narrower linewidth sources improve spectral purity and can reduce impairments that become increasingly significant in longer-reach and higher-rate optical transmission. Gnauck is directly concerned with modulation chirp and fiber-dispersion penalty, and a skilled artisan would have recognized that source-linewidth selection is another ordinary system-level parameter affecting transmission performance. Coleman shows that semiconductor laser designs achieving linewidths far below 200 kHz were known, making the claimed threshold merely one point within a known range of suitable narrow-linewidth designs. Choosing such a known narrow-linewidth laser diode for use in the combined system would therefore have been nothing more than the predictable selection of a known component to improve transmission robustness.
Claims 6, 7, 8, 9 and 10 are rejected under 35 U.S.C. § 103 as being unpatentable over Gnauck et al. in view of Jiang et al., and further in view of Aronson et al. (US20050169585A1) and Yadav et al. (US10348414B2).
Claim 6
With respect to claim 6, all limitations of claim 1 are taught by Gnauck and Jiang, except the remaining issue is whether the system also supports a second lower-rate electrical signal that is used by the modulator to generate a second modulated optical signal. However, within analogous art, Aronson teaches a serial electrical/optical transceiver path and states that “an optical transceiver module has a serial electrical interface with an electrical output port and an electrical input port” and further that “the transmitter 125 converts the serial electrical signal to an optical signal and transmits it onto the network” [Aronson, ¶¶ [0013] - [0014]; ¶ [0008]].
Aronson additionally teaches a transceiver specifically designed for different operating rates, including “a 10 Gb/s XFP transceiver that includes 8.5 Gb/s CDR bypass functionality” [Aronson, ¶ [0003], Abstract].
Yadav likewise teaches multi-rate operation in an optical receiver, explaining that its circuitry determines whether an incoming data signal has a first, second, or third data rate and then places the circuitry in bypass or CDR mode accordingly “A CDR circuit for use in an optical receiver is provided that performs automatic rate negotiation. The CDR circuit is configured to determine whether the incoming data signal has a first, second or third data rate. If the CDR circuit determines that the incoming data signal has the first data rate, the CDR circuit places itself in a bypass mode of operations so that CDR is not performed. If the CDR circuit determines that the incoming data signal has the second or third data rates, the CDR circuit places itself in a CDR mode of operations and performs CDR on the incoming data signal” [Yadav, Abstract].
These teachings show that the same optical link architecture was known to handle a higher-rate signal and also a lower-rate signal, with the transmitter still converting the lower-rate electrical signal into a corresponding optical signal for transmission.
One of ordinary skill in the art would have been motivated to configure the combined Gnauck/Jiang system to operate at multiple data rates, including a lower data rate in addition to a higher data rate, because the art expressly recognized the commercial value of transceivers that interoperate across different standards and host environments. Aronson shows that a single transmitter/receiver architecture can accept serial electrical data at different rates and can still convert those data into transmitted optical signals. Yadav reinforces that multi-rate operation and rate-dependent receiver behavior were known and desirable. Applying those teachings to Gnauck’s lithium niobate externally modulated transmitter would have been a predictable extension of known multi-rate transceiver design principles: the same optical carrier and modulator can be driven by a first electrical signal at a higher rate and by a fourth electrical signal at a lower rate to generate corresponding optical outputs. Such an adaptation would have offered interoperability and system flexibility without changing the basic operation of the transmitter, the fiber link, or the receiver.
Claim 7
With respect to claim 7, all limitations of claim 6 are taught by Gnauck, Jiang, Aronson and Yadav. However, within analogous art, Aronson teaches a standard “10 Gb/s XFP transceiver” with lower-rate bypass functionality “[0003] The present invention relates generally to transceiver modules. More particularly, an exemplary embodiment of the invention is concerned with a 10 Gb/s XFP transceiver that includes 8.5 Gb/s CDR bypass functionality”
[Aronson, ¶ [0003]].
Further, Elahmadi teaches that “The XFI interface 1802 is configured to transmit/receive a 10.3 Gb/s signal” [Elahmadi, ¶ [0110]].
Additionally, Yadav teaches multi-rate operation in which the circuitry distinguishes between 8 GHz, 16 GHz, and 32 GHz operating conditions and specifically states that “When the incoming data signal is either a 16 GHz signal or a 32 GHz signal, the CDR circuitry … performs CDR … [and] when the incoming data signal is an 8 GHz signal, the PLL … is bypassed” [Yadav, col. 3-4]
These references teach lower-rate operating points that are below the higher 25 Gb/s operating point of claim 2 while still at or above 10 Gb/s, including 10 Gb/s, 10.3 Gb/s, and 16 GHz/approximately 16 Gb/s class serial operation.
One of ordinary skill in the art would have been motivated to select a lower operating rate that is below the higher 25 Gb/s operating point yet still at or above 10 Gb/s because the prior art expressly identified these rates as practical, standard-compliant, and commercially useful intermediate operating points for optical transceivers. Once the artisan was motivated, as discussed for claim 6, to provide a multi-rate transmitter/receiver architecture, choosing a lower-rate operating point such as 10 Gb/s, 10.3 Gb/s, or 16 Gb/s-class operation would have been an obvious and predictable choice from among known options. The selection of such a lower rate would not require inventive skill; it would merely tailor the known architecture to a desired interoperability target or performance budget using well-understood operating modes already taught in the art.
Claim 8
With respect to claim 8, all limitations of claim 6 are taught by Gnauck, Jiang, Aronson and Yadav. However, within analogous art, Jiang teaches an EDC circuit coupled downstream of the optical-to-electrical conversion path and states that the received electrical signal is provided “to an analog to digital converter (ADC) circuitry … and subsequently to an electronic dispersion compensation (EDC) circuitry” [Jiang, ¶ [0042]].
Additionally, Yadav expressly teaches rate-based control logic, stating that its “data rate determination and control logic [is] configured to determine which of the first, second and third data rates the incoming data signal has” and that the logic causes the circuitry to be placed “in one of a CDR bypass mode of operations and a CDR mode of operations based on the determined data rate” [Yadav, claim 1, col. 3-6].
These teachings render obvious the claimed EDC chip determining how much compensation is to be applied according to the data transmission rate corresponding to the received signal.
One of ordinary skill in the art would have been motivated to make the amount of receiver-side compensation depend on the data rate because the impairments experienced by optical systems, as well as the appropriate equalization or recovery behavior, vary with rate. Jiang already teaches placing EDC in the receiver processing chain to compensate impairments associated with transmission through the optical channel. Yadav teaches that the receiver determines the operating data rate and changes its processing mode based on that rate. Combining these teachings would have been a straightforward application of known adaptive receiver design principles: when rate is determined, the compensation processing can be selected, scaled, or bypassed accordingly. This would have predictably optimized receiver operation for multiple data-rate modes without altering the basic transmitter or channel architecture.
Claim 9
With respect to claim 9, all limitations of claim 8 are taught by Gnauck, Jiang, Aronson and Yadav. However, within analogous art, Aronson expressly teaches lower-rate bypass behavior, stating that the invention concerns “a 10 Gb/s XFP transceiver that includes 8.5 Gb/s CDR bypass functionality” [Aronson, ¶ [0003]].
Aronson further explains that “XFP transceiver 3000 can be used at data rates different than typical 10 Gb/s applications, such as 8.5 Gb/s, as a result of a CDR bypass feature … [which] allows the high-speed data stream to bypass the CDR unit and be output directly” [Aronson, ¶ [0133]].
Yadav likewise teaches that “when the incoming data signal is an 8 GHz signal, the PLL … is bypassed such that CDR is not performed” [Yadav, col. 3-4], and that bypass occurs when the first data rate is detected [Yadav, col. 8-10],
These teachings render obvious a receiver-side mode in which phase-related compensation/recovery is not implemented for the lower-rate signal.
One of ordinary skill in the art would have been motivated to omit or suppress phase recovery/compensation processing for sufficiently low-rate signals because the art expressly teaches that certain compensation functions, such as CDR, need not be performed at the lower operating rate and can instead be bypassed. Aronson provides the practical reason: lower-rate operation can tolerate simplified processing, allowing direct output and reduced circuitry burden. Yadav confirms the same engineering principle in automatic-rate-negotiation circuitry. Applying that known lower-rate bypass behavior to Jiang ’s receiver-side post-detection compensation chain would have been a predictable adaptation in which the lower-rate mode receives less or no phase-oriented compensation while higher-rate modes continue to receive fuller processing. This would have simplified lower-rate operation and conserved power/complexity while maintaining functionality across rate modes.
Claim 10
With respect to claim 10, all limitations of claim 6 are taught by Gnauck, Jiang, Aronson and Yadav. However, within analogous art, Aronson teaches bypass hardware within the receiver processing path.
Aronson states that the integrated circuit may include “a bypass module for example for bypassing the eye opener(s) under certain conditions” and that “the data path(s) may include two or more eye openers, each suited for a different data rate” [Aronson, ¶ [0014]].
Aronson also expressly teaches that the lower-rate mode “allows the high-speed data stream to bypass the CDR unit and be output directly” [Aronson, ¶ [0133]].
Yadav similarly teaches “CDR bypass circuitry configured to cause the incoming data signal to be sent to an output … without performing CDR when the CDR circuit is in the bypass mode of operations” [Yadav, claim 1].
Thus, the combined references teach a bypass signal line inside the receiver processing circuitry and switching of the lower-rate signal through that bypass path when the lower-rate mode is detected.
One of ordinary skill in the art would have been motivated to implement an explicit bypass signal line in the receiver processing path because the prior art teaches that lower-rate operation can advantageously bypass more elaborate recovery circuitry. Aronson teaches both the design concept and the practical implementation of a bypass feature within the data path, while Yadav provides clear control logic that routes the signal according to the detected data rate. Integrating such bypass switching into the combined receiver of Jiang would have been entirely consistent with ordinary receiver engineering practice, allowing lower-rate signals to traverse a simpler path and higher-rate signals to traverse a more intensive compensation path. The result would have been predictable, namely lower complexity and appropriate signal handling tailored to the detected operating rate.
Claims 11 and 12 are rejected under 35 U.S.C. § 103 as being unpatentable over Gnauck et al. in view of Jiang et al., and further in view of Aronson et al., and Yadav et al., and further in view of Pruneri et al. (US6760493B2) and Tavlykaev et al. (US20030228081A1).
Claim 11
With respect to claim 11, all limitations of claims 1 and 6 are taught by Gnauck, Jiang, Aronson and Yadav, in that the base combination teaches the inherited system limitations from claims 1 and 6, as discussed above, including the optical transmission system, optical fiber, photodiode/receiver-side processing, and lower-rate signal operation.
However, within analogous art, for the detailed lithium niobate modulator structure now recited, Pruneri teaches a lithium niobate Mach-Zehnder modulator with optical splitting and combining elements. Specifically, Pruneri teaches “a Mach-Zehnder interferometer comprising an input optical waveguide … a first Y-junction … for splitting an input optical signal … into two optical signals propagating along two generally parallel optical waveguides … [and] a second Y-junction … for combining the two optical signals into an output optical signal” [Pruneri, col. 2-3].
This directly teaches an optical splitting element, two optical splitting paths, and an optical combining element.
Pruneri further teaches an electrode system associated with those two paths, stating that “the electrode system may comprise at least two ground electrodes … and at least a hot electrode extending between the ground electrodes” [Pruneri, col. 5-6].
Tavlykaev likewise teaches a coplanar arrangement in which “Each of the CPW segments includes a hot electrode and a ground plane disposed on each side of the hot electrode” [Tavlykaev, ¶ [0014]].
Together, these teachings render obvious the recited radio-frequency signal channel disposed in parallel between the two optical splitting paths, and the two ground channels disposed in parallel with and coupled to that signal channel, for modulating the two optical splitting signals.
One of ordinary skill in the art would have been motivated to implement the detailed electrode arrangement of Pruneri and Tavlykaev within the inherited multi-rate optical transmission system because those references address the exact design of lithium niobate / electro-optic Mach-Zehnder modulators used to modulate optical signals propagating along split waveguide arms. Gnauck already teaches a lithium niobate external modulator in an optical transmission system, but Pruneri provides more explicit detail on Y-junction splitting/combining and the corresponding electrode geometry, while Tavlykaev provides express teaching of a hot electrode with ground planes on each side in a coplanar arrangement. A skilled artisan seeking to implement or refine the modulator portion of Gnauck’s system would have looked to such references for ordinary structural details of the electrode system. Combining those teachings would have predictably yielded the claimed arrangement of a splitting element, two optical paths, an RF/hot channel disposed between the paths, parallel grounded channels, and a combining element. The combination would merely substitute one known detailed Mach-Zehnder modulator layout for another within an otherwise conventional optical transmission architecture.
Claim 12
With respect to claim 12, all limitations of claim 11 are taught by Gnauck, Jiang, Aronson, Yadav, Pruneri and Tavlykaev. However, within analogous art, Pruneri expressly teaches a dual-hot-electrode arrangement, stating that “the electrode system comprises two hot electrodes, each one extending over said section of a respective waveguide” and further that “said electrode system comprises an integrated power splitter … for receiving an externally-generated modulating voltage and supplying it to the two hot electrodes” [Pruneri, col. 5-6 claim 8-9]
Pruneri also teaches that “the waveguides are optically connected by means of respective Y-junctions … [and] the two hot electrodes may merge together at said Y-junctions” [Pruneri, col. 17-18].
These teachings render obvious the claimed set of hot electrodes disposed at the two optical splitting paths and configured to implement phase modulation on the two optical splitting signals.
One of ordinary skill in the art would have been motivated to use a set of hot electrodes on the two optical splitting paths because such dual-drive or dual-hot-electrode arrangements were known ways of efficiently imparting electro-optic phase modulation to the respective interferometer arms. Pruneri expressly presents that arrangement in the context of a closely analogous electro-optic modulator, and the use of such electrodes would have been fully compatible with the lithium niobate modulator environment already taught by Gnauck. Employing hot electrodes on the split paths would have predictably enabled controlled phase modulation of the two optical signals, thereby achieving the known modulation behavior of a Mach-Zehnder interferometer. This is a textbook combination of known modulator structures used for their expected function.
Claim 13 is rejected under 35 U.S.C. § 103 as being unpatentable over Gnauck et al. in view of Jiang et al., and further in view of Aronson et al. and Yadav et al., and further in view of Pruneri et al., and Tavlykaev et al., and further in view of Hatta et al. (US7010179B2).
Claim 13
With respect to claim 13, all limitations of claim 11 are taught by Gnauck, Jiang, Aronson, Yadav, Pruneri and Tavlykaev. However, within analogous art, Hatta teaches terminating/impedance-matching resistors between signal transmission lines and ground lines, specifically reciting “a first terminal resistor connected between a terminal end of the first transmission line and the ground line, [and] a second terminal resistor connected between a terminal end of the second transmission line and the ground line” [Hatta, claim 1].
Hatta further teaches that “Terminal resistors R1 and R2 for impedance-matching are formed between the terminal ends of the transmission lines 32 and 34 and the common connection portions of the ground lines” [Hatta, col. 7].
These teachings render obvious the claimed terminating resistor disposed between the radio frequency signal channel and the two ground channels and coupled thereto.
One of ordinary skill in the art would have been motivated to provide a terminating resistor in the modulator electrode structure because the art expressly recognized impedance matching and high-speed signal integrity as important concerns in electro-optic modulators and transmission-line driven optical devices. Hatta directly teaches terminal resistors between transmission lines and common ground-line connections for impedance matching. Incorporating such a known termination arrangement into the detailed modulator geometry of claim 11 would have been a routine engineering measure undertaken to reduce reflections and preserve bandwidth. The resulting structure would have performed in the expected manner by terminating the RF drive path relative to the grounded conductors, thereby improving high-speed modulation behavior. Accordingly, the addition of the terminating resistor would have been an obvious refinement of the otherwise conventional modulator layout.
It is noted that any citations to specific, pages, columns, lines, or figures in the prior art references and any interpretation of the reference should not be considered to be limiting in any way. A reference is relevant for all it contains and may be relied upon for all that it would have reasonably suggested to one having ordinary skill in the art. See MPEP 2123.
Conclusion
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/MOHAMMED ABDELRAHEEM/Examiner, Art Unit 2635
/DAVID C PAYNE/Supervisory Patent Examiner, Art Unit 2635