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 .
Priority
Acknowledgment is made of applicant’s claim for foreign priority under 35 U.S.C. 119 (a)-(d). The certified copy has been filed in parent Application CN202410218212.0, filed on 27 February 2024.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 16 January 2025 has been considered by the examiner.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to 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 later invention.
Claims 1-2 and 16-18 are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Alfiad (USPUB 20160112138), Li in 'A Simple Photonic System for DFS and AOA Simultaneous Measurement', and Fitzgerald (USPUB 20070280704).
As per claims 1 and 17-18,
Alfiad teaches an optical transmitter as well as an apparatus and method to monitor an analog characteristic of an optical transmitter (Paragraph [0001] – "This invention relates to an optical transmitter and to a method for monitoring signal quality of a modulated optical signal output by a transmitter."; Paragraph [0008] – "the processing unit of the monitoring circuit comprises a digital signal processor adapted to calculate an optimal pre-distortion function and/or correction parameters to be used by the transmitter to compensate for transmitter impairments, in particular for nonlinear transfer functions and/or bandwidth limitations of transmitter components."; Paragraph [0009] – "These correction parameters can for instance be related to the IQ-imbalance (the amount of power imbalance at the transmitted between I and Q), IQ-skew (measure how much is the delay between the I and Q components and request the transmitter to correct for that) and the DC bias voltages used for the optical modulator."), comprising:
a processor coupled to a memory (FIG. 13, processing unit 6C, data memory 16; Paragraph [0054] – "The low-speed digital signal processor DSP of the processing unit 6C can comprise an adder 14 adding the in-phase and quadrature signal components and supplying the complex signal to a finite impulse response filter FIR 15 which is adapted to construct a transfer function of the transmitter 1 using filter taps, wherein the constructed transfer function can be stored in a data memory 16.") and configured to,
input a first signal to a first electro-optical converter to obtain an optical signal to-be-measured (Paragraph [0051] – "The optical modulator 2 of the transmitter 1 is configured to modulate an amplitude and/or a phase and/or a polarization of the optical signal output by the laser source 3 to generate the modulated optical signal output by the transmitter 1. In a possible exemplary embodiment, the optical modulator 2 can comprise one or several Mach-Zehnder modulators MZM having nonlinear transfer functions as illustrated in FIGS. 1a, 1b."; Paragraph [0050] – "The modulated optical signal output by the optical modulator 2 is tapped by means of a second polarization maintaining coupler 7 and also supplied to the optical front end 6A of the monitoring unit 6 as shown in FIG. 2.");
Alfiad does not teach inputting a second signal to a second electro-optical converter to obtain a modulated local signal. However, in an analogous art, Li teaches a system utilizing two modulators that effectively teaches the limitation:
input a second signal to a second electro-optical converter to obtain a modulated local signal (Page 1 – "The system applies two parallel push–pull Mach–Zehnder modulators (MZMs) for carrier suppression dual-sideband (CS-DSB) modulation."; Page 2 – "In this paper, a simple photonics method for the simultaneous measurement of the DFS and AOA is presented. In this system, the optical carrier is divided into two channels and sent to two MZMs. A pair of reference signals are fed into the radio frequency (RF) ports of two push–pull MZMs after combining them with two echo signals. Both MZMs realize the carrier suppression dual-sideband (CS-DSB) modulation."),
One of ordinary skill in the art would consider a Mach-Zehnder modulator as an electro-optical converter. Furthermore, one of ordinary skill in the art would be motivated to utilize the parallel MZM configuration taught by Li according to the teachings of Alfiad (Paragraph [0051] – "In a possible exemplary embodiment, the optical modulator 2 can comprise one or several Mach-Zehnder modulators MZM having nonlinear transfer functions as illustrated in FIGS. 1a, 1b.").
Therefore, it would have been obvious to one of ordinary skill in the art at the effective filing date of the claimed invention to utilize the known configuration taught by Li in the possible embodiment taught by Afliad.
Furthermore, Alfiad teaches the following limitation:
wherein the second signal is determined according to the first signal and a to-be-monitored analog characteristic of the first electro-optical converter (Paragraph [0008] – "the processing unit of the monitoring circuit comprises a digital signal processor adapted to calculate an optimal pre-distortion function and/or correction parameters to be used by the transmitter to compensate for transmitter impairments"; Paragraph [0009] – "These correction parameters can for instance be related to the IQ-imbalance (the amount of power imbalance at the transmitted between I and Q), IQ-skew (measure how much is the delay between the I and Q components and request the transmitter to correct for that) and the DC bias voltages used for the optical modulator"; Claim 4 – "the monitoring circuit supplies a feedback control signal to adjust driving signals applied to the optical modulator according to the calculated pre-distortion function and/or correction parameters.");
Neither Alfiad nor Li teach performing correlation processing on the optical signal to-be-measured and the modulated local signal to obtain at least one correlation quantity. However, in an analogous art, Fitgerald teaches a signal receiver utilizing optical processing that teaches the limitation:
perform correlation processing on the optical signal to-be-measured and the modulated local signal to obtain at least one correlation quantity (Paragraph [0021] – "the optical detector may be a low-bandwidth optical detector to detect the optical power of the twice modulated optical signal and provide the detected signal being proportional to an integrated optical power. The processing unit may control delay of the reference signal to the second optical modulator and extract or measure cross-correlation between the received RF signal and the reference signal based upon detected integrated optical power for different delay settings."; Paragraph [0038] – "The processing unit 30 has the ability to delay the reference signal in time. By measuring the integrated optical power for different delay settings, the cross-correlation between the RF signal and the reference signal can be measured.");
One of ordinary skill in the art would have been motivated to combine the teachings of Fitzgerald with the teachings of Alfiad and Li as Fitzgerald establishes a known method of utilizing time delay to compare signals, which would lend to the IQ imbalance and IQ skew calculations taught by Alfiad.
Lastly, Alfiad teaches the following limitation:
estimate an analog characteristic of the first electro-optical converter according to the at least one correlation quantity (Paragraph [0054] – "Different DSP blocks can for instance calculate the IQ imbalance and IQ skew… the measuring unit 13 measures the power difference and time delay between the in-phase and quadrature phase signal components of the received signals… The low-speed digital signal processor DSP of the processing unit 6C can comprise an adder 14 adding the in-phase and quadrature signal components and supplying the complex signal to a finite impulse response filter FIR 15 which is adapted to construct a transfer function of the transmitter 1").
As per claim 2, the combination of Alfiad, Li, and Fitzgerald teaches the limitations of claim 1.
Fitzgerald teaches wherein the at least one correlation quantity represents a value of a cascaded impulse response (Paragraph [0021] – "The processing unit may control delay of the reference signal to the second optical modulator and extract or measure cross-correlation between the received RF signal and the reference signal based upon detected integrated optical power for different delay settings."; Paragraph [0020] – "a first optical modulator to modulate the optical signal with a received RF signal and provide a modulated optical signal. A second optical modulator modulates the modulated optical signal with a reference signal and provides a twice modulated optical signal.") of the first electro-optical converter and the second electro-optical converter (Paragraph [0024] – "modulating the optical signal with a received RF signal to provide a modulated optical signal, modulating the modulated optical signal with a reference signal to provide a twice modulated optical signal…. Modulating may include the use of at least one of a Mach-Zehnder Modulator (MZM) and an Indium Phosphide (InP) modulator.") at a first moment (Paragraph [0021] – "The processing unit may control delay of the reference signal to the second optical modulator and extract or measure cross-correlation between the received RF signal and the reference signal based upon detected integrated optical power for different delay settings."), and the first moment depends on a relative delay of the first signal and the second signal (Paragraph [0021] – "The processing unit may control delay of the reference signal to the second optical modulator and extract or measure cross-correlation between the received RF signal and the reference signal based upon detected integrated optical power for different delay settings.").
Although Fitzgerald does not explicitly state wherein the at least one correlation quantity represents a value of a cascaded impulse response, one of ordinary skill in the art would recognize that a cascaded impulse response is inferred from the two serial modulation stages. As the reference signal is applied to the second modulator after the received signal has already been applied to the first modulator, the detected response corresponds to the combined or cascaded response of the two modulation stages. The response is sampled for different relative delay settings, such that a particular correlation value corresponds to a particular point of the delay-dependent response.
As per claim 16, the combination of Alfiad, Li, and Fitzgerald teach the limitations of claim 1.
Fitzgerald teaches wherein the first electro-optical converter and the second electro-optical converter are connected in series (Paragraph [0020] – "a first optical modulator to modulate the optical signal with a received RF signal and provide a modulated optical signal. A second optical modulator modulates the modulated optical signal with a reference signal and provides a twice modulated optical signal.");
the first electro-optical converter generates the optical signal to-be-measured based on an optical carrier and the first signal (Paragraph [0020] – "an optical source (e.g. a mode-locked laser) providing an optical signal, and a first optical modulator to modulate the optical signal with a received RF signal and provide a modulated optical signal."), and the second electro-optical converter generates the modulated local signal based on the optical signal to-be-measured and the second signal (Paragraph [0020] – "A second optical modulator modulates the modulated optical signal with a reference signal and provides a twice modulated optical signal.");
the modulated local signal is input to a photoelectric converter to obtain an electrical signal (Paragraph [0023] – "The optical detector may be a low-bandwidth optical detector to detect the optical power of the twice modulated optical signal and provide the detected signal being proportional to an integrated optical power."); and
the electrical signal generates at least one correlation quantity after being electrically averaged (Paragraph [0025] – "Detecting the optical power of the twice modulated optical signal may provide a detected signal that is proportional to the integrated optical power. And, processing may include controlling delay of the reference signal, and extracting or measuring cross-correlation between the received RF signal and the reference signal based upon integrated optical power of the detected signal for different delay settings.").
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over the combination of Alfiad (USPUB 20160112138), Li in 'A Simple Photonic System for DFS and AOA Simultaneous Measurement', Fitzgerald (USPUB 20070280704), and Tang (USPUB 20220368512).
As per claim 3, the combination of Alfiad, Li, and Fitzgerald teaches the limitations of claim 1.
The combination of Alfiad, Li, and Fitzgerald does not teach the limitations of the claim.
However, in an analogous art, Tang teaches wherein in case of the first electro-optical converter as a transmitter transmitting at least two superimposed signals (Paragraph [0008] – "The device has an electro-optic modulator (EOM) configured to generate an optical signal based on the modified digital data signal…. The device has a control unit configured to determine an IQ time skew between an in-phase component and a quadrature component of the optical signal based on the first pilot tone power and second pilot tone power."), each signal of the at least two superimposed signals is monitored at least once (Paragraph [0008] – "The device has a control unit configured to determine an IQ time skew between an in-phase component and a quadrature component of the optical signal based on the first pilot tone power and second pilot tone power."; Paragraph [0011] – "calculating a power ratio between the first pilot tone power and second pilot tone power…"; Claim 17 – "combining a first pilot tone with a first frequency band of a digital data signal, and combining a second pilot tone with a second frequency band of the digital data signal, thereby generating a modified digital data signal") by at least one correlation processing separately to obtain at least two correlation quantities (Paragraph [0011] – "for each of the plurality of IQ time-skew bias values, calculating a power ratio between the first pilot tone power and second pilot tone power for the respective IQ time-skew bias value; calculating the IQ time skew based on the plurality of IQ time-skew bias values and the respective plurality of power ratios"), and the analog characteristic of the first electro-optical converter is estimated according to the at least two correlation quantities (Paragraph [0075] – "The control unit 302 uses the power ratio information 242 to determine the IQ skew of the optical signal 124"; Paragraph [0091] – "The IQ time skew is calculated based on the plurality of IQ time-skew bias values and the respective plurality of power ratios received from the pilot tone power ratio detection unit 238 as power ratio information 242.").
One of ordinary skill in the art would recognize that the teachings of Tang establish a known alternative for determining an analog characteristic.
Therefore, it would have been obvious to one of ordinary skill in the art at the effective filing date of the claimed invention to substitute the teachings of Tang into the combination of Alfiad, Li, and Fitzgerald in order to achieve the predictable result of determining an analog characteristic using two correlation quantities obtained from monitoring two superimposed signals.
Claims 4-6 are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Alfiad (USPUB 20160112138), Li in 'A Simple Photonic System for DFS and AOA Simultaneous Measurement', Fitzgerald (USPUB 20070280704), and Hasegawa-Johnson in 'Lecture 12: Linearity and Shift-Invariance'.
As per claims 4-6, the combination of Alfiad, Li, and Fitzgerald teaches the limitations of claim 1.
Alfiad teaches wherein the analog characteristic is frequency-independent IQ imbalance, IQ skew, or frequency-dependent IQ imbalance of the first electro-optical converter as a coherent transmitter (Paragraph [0054] – "In a possible embodiment, the measuring unit 13 measures the power difference and time delay between the in-phase and quadrature phase signal components of the received signals. Different DSP blocks can for instance calculate the IQ imbalance and IQ skew…. The processing unit 6C comprises a measuring unit 13 to measure an IQ power imbalance between the in-phase signal component I and the quadrature phase signal component Q received from the optical front end 6A and converted by the ADC conversion stage 6B.").
Although Alfiad does not explicitly teach the limitation disclosing the first signal, one of ordinary skill in the art would recognize the first signal inherently takes on the form stated in the limitation, as I and Q components are 90 degrees out of phase with each other.
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Furthermore, although Alfiad does not explicitly teach the limitation disclosing the second signal and the generation of a modulated local signal, one of ordinary skill in the art would recognize that the form of the input is inherent to signal processing and that modulating an input would also inherently result in the convolution of the input with the impulse response of the system, resulting in the listed equations for the generated modulated local signal, as taught by Hasegawa-Johnson (Slides 26-27 – "Let H be any system,
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If H is linear and shift-invariant, then whatever processes it performs can be equivalently replaced by a convolution:
The weights h[m] are called the 'impulse response' of the system.").
One of ordinary skill in the art would recognize that the second signal which is input to the electro-optical converter (the electro-optical converter being the system) is equivalent to x[n], and the generated modulated local signal is equivalent to y[n].
Claims 7-9 are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Alfiad (USPUB 20160112138), Li in 'A Simple Photonic System for DFS and AOA Simultaneous Measurement', Fitzgerald (USPUB 20070280704), Roelefs (USPUB 20210288658), and Hasegawa-Johnson in 'Lecture 12: Linearity and Shift-Invariance'.
As per claims 7-9, the combination of Alfiad, Li, and Fitzgerald teach the limitations of claim 1.
The combination of Alfiad, Li, and Fitzgerald does not teach the limitations of the claims.
However, in an analogous art, Roelofs teaches wherein the analog characteristic is a frequency-independent, skew, or frequency-dependent difference between different segments (Paragraph [0025] – "The optical modulator 300 preferably includes multiple independently-addressable segments 310… Preferably, each segment 310 can be independently controlled by a separate electrical input signal."; Paragraph [0026] – "Each segment 310 is preferably associated with a modulation response, wherein the modulation response is defined as the amount (e.g., absolute or relative magnitude) of optical modulation for a given electrical input (e.g., per unit of electrical input intensity)."; Paragraph [0027] – "In some embodiments, each segment 310 of the modulator has a substantially different modulation response.") or between different combinations of segments assigned according to bits within the first electro-optical converter as a transmitter (Paragraph [0034] – "the least significant bit of the input controls the segment with the smallest modulation response (e.g., the shortest segment), the most significant bit controls the segment with the largest modulation response (e.g., the longest segment), and the intermediate bits control the segments of intermediate modulation response (wherein bits of greater significance control higher modulation response segments than bits of lesser significance).").
It would have been obvious to one of ordinary skill in the art to combine the teachings of Alfiad, Li, and Fitgerald with the segment analysis taught by Roelofs, as it is a known method of determining the response of a modulator.
Roelefs does not explicitly teach the limitation disclosing the first signal and its form. However, one of ordinary skill in the art would recognize the first signal inherently takes on the form stated in the limitation when loaded onto a segment.
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Although Roelefs does not explicitly teach the limitations disclosing the second signal and the generation of a modulated local signal, one of ordinary skill in the art would recognize that the form of the input is inherent to signal processing and that modulating an input would also inherently result in the convolution of the input with the impulse response of the system, resulting in the listed equations for the generated modulated local signal, as taught by Hasegawa-Johnson (Slides 26-27 – "Let H be any system,
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If H is linear and shift-invariant, then whatever processes it performs can be equivalently replaced by a convolution:
The weights h[m] are called the 'impulse response' of the system.").
One of ordinary skill in the art would recognize that the second signal which is input to the electro-optical converter (the electro-optical converter being the system) is equivalent to x[n], and the generated modulated local signal is equivalent to y[n].
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over the combination of Alfiad (USPUB 20160112138), Li in 'A Simple Photonic System for DFS and AOA Simultaneous Measurement', Fitzgerald (USPUB 20070280704), and Mizuguchi (USPUB 20110044702).
As per claim 10, the combination of Alfiad, Li, and Fitzgerald teaches the limitations of claim 1.
The combination of Alfiad, Li, and Fitzgerald does not teach the limitations of the claim.
However, in an analogous art, Mizuguchi teaches wherein the analog characteristic is a difference between different polarization states as a whole within the first electro-optical converter as a dual polarization transmitter (Paragraph [0040] – "The polarization multiplexed optical signal carries data to a receiving station using a pair of polarized waves (H polarization and V polarization) that are orthogonal to each other. Here, if the characteristics of the H polarization signal and the V polarization signal are different from each other, the characteristics of the polarization multiplexed optical signal deteriorate. Therefore, in the polarization multiplexed optical transmitter according to the embodiment, control to make the characteristics of the H polarization signal and the H polarization signal the same as each other or approximately the same as each other is performed."), or a difference between different segments or between different combinations of segments assigned according to bits in different polarization states within the dual polarization transmitter (Paragraph []);
H and V respectively represent an H polarization state and a V polarization state of the dual polarization transmitter (Paragraph [0055] – "A power splitter 41 splits a portion of the polarization multiplexed optical signal output from the polarization beam combiner 3. The portion of the polarization multiplexed optical signal split by the power splitter 41 contains the H polarization signal and the V polarization signal."), and second signals of H branch and V branch of the dual polarization transmitter are B H 9 [n] and B V 9 [n] respectively.
Mizuguchi does not explicitly teach the alternative analog characteristic: a difference between different segments or between different combinations of segments assigned according to bits in different polarization states within the dual polarization transmitter.
However, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate the teachings of Mizuguchi into the transmitter analog-characteristic monitoring system taught by the combination Alfiad, Li, and Fitzgerald to monitor a difference between the H and V polarization states of a dual-polarization transmitter. Mizuguchi recognizes that differences in characteristics between the H-polarization and V-polarization signals degrade the characteristics of the polarization-multiplexed optical signal and therefore teaches detecting and controlling such differences. In particular, Mizuguchi identifies timing error, rising/falling-time difference, and optical power difference between the H and V polarization signals as characteristics that can be detected and controlled.
Mizuguchi does not explicitly teach the limitation: second signals of H branch and V branch of the dual polarization transmitter are B H 9 [n] and B V 9 [n] respectively. However, one of ordinary skill in the art would recognize the designations as nomenclature used by the application to identify the respective second signals associated with the H and V branches. Mizuguchi's respective H and V branch signals are functionally equivalent.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over the combination of Alfiad (USPUB 20160112138), Li in 'A Simple Photonic System for DFS and AOA Simultaneous Measurement', Fitzgerald (USPUB 20070280704), and Kan (USPUB 20160028487).
As per claim 11, the combination of Alfiad, Li, and Fitzgerald teaches the limitations of claim 1.
The combination of Alfiad, Li, and Fitzgerald does not teach the limitations of the claim.
However, in an analogous art, Kan teaches wherein the analog characteristic is an analog characteristic of the first electro-optical converter under a specific symbol or a specific symbol sequence (Paragraph [0006] – "In one embodiment, the disclosure includes an optical transceiver comprising a transmitter configured to transmit a first signal, and a receiver coupled to the transmitter and configured to receive a first compensation, wherein the first compensation is based on a pattern-dependent analysis of the first signal");
the first signal is expressed as A[n], the second signal B 10 [n] is a constant when corresponding to the specific symbol, or,
the second signal B 11 [n] is a constant when corresponding to a central symbol of the specific symbol sequence (Claim 4 – " the transmitter is further configured to compensate the second signal by applying the adjustment to a center symbol of a sequence of the second signal"; Claim 3 – "the PD-LUT comprises a pattern index and an adjustment corresponding to the pattern index."), and the modulated local signal is a pulse signal.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the transmitter analog-characteristic system taught by the combination of Alfiad, Li, and Fitgerald to characterize transmitter impairments according to particular transmitted symbols or symbol sequences as taught by Kan. Kan recognizes that transmitter impairments can be pattern dependent and provides a pattern-dependent analysis for identifying the impairment associated with a particular symbol pattern. In particular, Kan teaches a pattern-dependent look-up table having a pattern index and a corresponding adjustment, and further teaches applying the corresponding adjustment to a center symbol of a sequence. Such a modification would account for pattern-dependent transmitter impairments rather than treating the transmitter characteristic as independent of the transmitted data.
Kan does not explicitly teach the limitations: the first signal is expressed as A[n], the second signal B 10 [n] is a constant when corresponding to the specific symbol; and the modulated local signal is a pulse signal. However, one of ordinary skill in the art would recognize that a signal representing the occurrence of a selected pattern necessarily has one value when the selected pattern occurs and another value when it does not. Furthermore, one of ordinary skill in the art would reasonably infer that when such as signal is used to generate the corresponding local modulation signal, the result has a pulse-like form corresponding to the selected sequence.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over the combination of Alfiad (USPUB 20160112138), Li in 'A Simple Photonic System for DFS and AOA Simultaneous Measurement', Fitzgerald (USPUB 20070280704), and Ding (USPUB 20170059888).
As per claim 12, the combination of Alfiad, Li, and Fitzgerald teaches the limitations of claim 1.
The combination of Alfiad, Li, and Fitzgerald does not teach the limitations of the claim.
However, in an analogous art, Ding teaches wherein the analog characteristic is static and dynamic analog characteristics of each segment within the first electro-optical converter as a transmitter with a multi-segment modulator cascaded structure (Paragraph [0009] – "there is provided an optical modulator comprising:… a succession of serially optically coupled optical modulator segments extending between the input and output optical ports for modulating the optical carrier wave so as to obtain the modulated optical signal; a plurality of segment drivers, wherein each segment driver has associated: a low voltage Vlow, a high voltage Vhigh, a unique offset voltage Vos, and a threshold voltage Vth, wherein each segment driver is electrically coupled to one of the succession of the modulator segments"; Paragraph [0008] – "Parameters of the segment drivers may be selected or programmed so as to approximate a pre-defined overall transfer function"; Paragraph [0081] – "a feedback signal 1543 representative of the modulated optical signal 307… to linearize the overall response function of the modulator apparatus 1500, for calibration purposes, etc.");
(Paragraph [0009] – "each segment driver is electrically coupled to one of the succession of the modulator segments"; Paragraph [0069] – "the comparator module may be operationally coupled to the electrical input port 302 and the plurality of segment drivers, for providing individual control signals to the plurality of segment drivers").
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of Ding with the combination of Alfiad, Li, and Fitgerald as Ding provides a known method of determining the response of a modulator.
Ding does not explicitly teach the limitations disclosing the first signal, second signal, and the generation of the modulated local signal. However, one of ordinary skill in the art would recognize that modulating an input would inherently result in the convolution of the input with the impulse response of the system, resulting in the listed equations.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over the combination of Alfiad (USPUB 20160112138), Li in 'A Simple Photonic System for DFS and AOA Simultaneous Measurement', Fitzgerald (USPUB 20070280704), and Maechata (USPUB 20140198878).
As per claim 13, the combination of Alfiad, Li, and Fitzgerald teaches the limitations of claim 1.
The combination of Alfiad, Li, and Fitzgerald does not teach the limitations of the claim.
However, in an analogous art, Maechata teaches wherein the processor is further configured to: quantify the first signal or the second signal by using at least one bit, and input a quantized signal to the second electro-optical converter to obtain the modulated local signal (Paragraph [0087] – "In the delta-sigma modulator 25 shown in FIG. 1, an input (in the present embodiment, modulated wave) U is provided to the loop filter 27. An output Y from the loop filter 27 is provided to a quantizer (for example, a 1-bit quantizer or a multi-bit quantizer) 28.").
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate the teachings of Maechata with the teachings of Alfiad, Li, and Fitzgerald, to represent signals in a discrete, digital form, that can be stored, processed and transmitted efficiently.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over the combination of Alfiad (USPUB 20160112138), Li in 'A Simple Photonic System for DFS and AOA Simultaneous Measurement', Fitzgerald (USPUB 20070280704), and Ono (USPAT 6388786).
As per claim 14, the combination of Alfiad, Li, and Fitzgerald teaches the limitations of claim 1.
Alfiad teaches wherein the first electro-optical converter is a transmitter, or is a partial modulator of the transmitter, or is a direct modulation laser (Paragraph [0001] – "This invention relates to an optical transmitter and to a method for monitoring signal quality of a modulated optical signal output by a transmitter."; Paragraph [0004] – "the invention provides a transmitter with at least one optical modulator adapted to modulate the optical signal output by a laser source to generate a modulated optical signal").
Alfiad does not teach the limitation: the second electro-optical converter outputs a finite number of states.
However, in an analogous art, Ono teaches the limitation: the second electro-optical converter outputs a finite number of states (Col. 1, Lines 44-46 – "a binary inverted data signal is converted into a three-level data signal."; Col. 1, Lines 51-55 – "In this technique, the bias voltage is so adjusted that a three-level signal(−1, 0, 1) corresponds to a mountain(ON), a valley(OFF) and a neighboring mountain(ON) in the voltage-extinction characteristic of the push-pull optical intensity modulator."; Col. 1, Lines 57-59 – "the data signal is mapped into three states of (1, 0), (0, indefinite) and (1, π) to generate optical duobinary signal light.").
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the teachings of Alfiad, Li, and Fitzgerald to produce a finite number of output states in accordance with Ono demonstrating that discrete-state optical modulation, including three-level optical modulation, is a known technique for generating an optical transmission signal. Applying such a modulation technique would have yielded a predictable result and implementation for generating a modulated local signal using a limited number of modulation states.
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over the combination of Alfiad (USPUB 20160112138), Li in 'A Simple Photonic System for DFS and AOA Simultaneous Measurement', Fitzgerald (USPUB 20070280704), Abramovitz (USPAT 5420826), and Farina (USPUB 20090232517A1).
As per claim 15, the combination of Alfiad, Li, and Fitzgerald teaches the limitations of claim 1.
The combination of Alfiad, Li, and Fitzgerald does not teach the limitations of the claim.
However, in an analogous art, Abramovitz teaches wherein
the first electro-optical converter and the second electro-optical converter are connected in parallel (Claim 1 – "An apparatus comprising: … light beam generating means for generating collimated first and second light beams; a first light modulator for modulating the first light beam with a signal; a second light modulator for modulating the second light beam with a reference signal…"; Claim 8 – "The apparatus of claim 1, wherein said light beam generating means comprises: a laser diode for generating a laser beam; a collimating lens for collimating the laser beam; and a beam splitter for splitting the collimated laser beam into the collimated first and second light beams."; Claim 9 – "The apparatus of claim 8, wherein said beam splitter splits the collimated laser beam such that the collimated first and second light beams propagate along parallel optical paths.");
the first electro-optical converter generates the optical signal to-be-measured based on an optical carrier and the first signal, and the second electro-optical converter generates the modulated local signal based on the optical carrier and the second signal (Col. 7, Lines 4-7 – "First light modulator 42 modulates the first of the two light beams generated by light beam generating means 41 with a signal. Second light modulator 43 modulates the second light beam with a reference signal.");
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the teachings of Alfiad, Li, and Fitzgerald in accordance with the findings of Abramovitz, which showcase a known implementation of a first and second electro-optical converter.
Abramovitz does not teach the following limitations: wherein the optical signal to-be-measured and the modulated local signal are respectively input to a photoelectric multiplier to obtain a product electrical signal; and the product electrical signal generates at least one correlation quantity after being electrically averaged.
However, in an analogous art, Farina teaches wherein the optical signal to-be-measured and the modulated local signal are respectively input to a photoelectric multiplier to obtain a product electrical signal (Paragraph [0053] – "The cross-correlator 150, which in one embodiment is an analog multiplier (e.g., mixer) cross-correlates the electrical signal provided by the photodetector 140 with a data modulation signal provided by the data modulation signal source 170 to provide a quality of modulation signal."); and the product electrical signal generates at least one correlation quantity after being electrically averaged (Paragraph [0053] – "The cross-correlator 150, which in one embodiment is an analog multiplier (e.g., mixer) cross-correlates the electrical signal provided by the photodetector 140 with a data modulation signal provided by the data modulation signal source 170 to provide a quality of modulation signal.").
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the teachings of Alfiad, Li, Fitzgerald and Abramovitz in accordance with the findings of Farina, which showcase a known method of obtaining a correlation quantity from electro-optical converters.
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
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Ianelli (USPUB 20060210282)
Shankar (USPAT 9819412)
Chen (USPAT 10574362)
Ng (USPUB 20210119850)
Longquan Dai, et al., "Experimental Demonstration of Simultaneously Precise Tx and Rx Skew Calibration for Coherent Optical Transceiver," J. Lightwave Technol. 40, 1043-1054 (2022)
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/JACOB ETHAN DELA ROSA-FRIO/Examiner, Art Unit 2635
/DAVID C PAYNE/Supervisory Patent Examiner, Art Unit 2635
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