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 .
Claim Rejections - 35 USC § 112 - Indefinite
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.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 2 and 12 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 2 recites
The method of claim 1, wherein an overall time to complete the parallelized optical link calibration is independent of a number of the plurality of spans.
The claim recites a desired result (the overall time is independent of the number of spans) but does not require any particular steps. One interpretation is that the claim is reciting an inherent result of performing measurement and processing at the same time (as recited in claim 1), in which case it does not appear to further limit the scope of the claim from which it depends (see the 112(d) rejection below). In the interests of compact prosecution, the claim is also rejected here under 112(b) on the grounds that it is not clear what additional steps are within the scope of this claim (e.g., in the event Applicant argues that this claim further limits claim 1 without reciting any additional steps).
Claim 12 recites
The optical line system of claim 11, wherein an overall time to complete the parallelized optical link calibration is independent of a number of the plurality of spans.
This is rejected for the reasons discussed for claim 2.
Claim Rejections - 35 USC § 112 - Failure to Further Limit
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claims 2 and 12 are rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends.
Claim 2 recites
The method of claim 1, wherein an overall time to complete the parallelized optical link calibration is independent of a number of the plurality of spans.
This claim was rejected under 112(b), but in the interests of compact prosecution it is also being rejected under 112(d). In particular, this claim appears to have a scope in which it recites only inherent characteristics of performing measurement and processing in each node at the same time as set forth in claim 1. As a result, it does not appear to further limit the subject matter of the claim upon which it depends.
Claim 12 recites
The optical line system of claim 11, wherein an overall time to complete the parallelized optical link calibration is independent of a number of the plurality of spans.
This claim was rejected under 112(b), but in the interests of compact prosecution it is also being rejected under 112(d). In particular, this claim appears to have a scope in which it recites only inherent characteristics of performing measurement and processing in each node at the same time as set forth in claim 11. As a result, it does not appear to further limit the subject matter of the claim upon which it depends.
Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
Claim Rejections - 35 USC § 103 - Obvious
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.
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.
Claim(s) 1-5, 8-15, and 18-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over US 2020/0313380 (Pei) in view of US 2004/0028406 (Bortz) and US 6,222,668 (Dutrisac).
Regarding claim 1, Pei teaches a method of parallelized optical link calibration of an optical section having a plurality of spans interconnecting a transmit Optical Add/Drop Multiplexer (OADM) with a receive OADM via a plurality of line amplifiers (FIG. 7: plural spans connecting OADM node 52 with OADM node 54 via amps 74 in node 56), the method comprising steps of:
partitioning the optical section into a plurality of sub-sections, each including one or more spans of the plurality of spans (FIG. 7: sub-sections between the nodes 52, 54, 56);
utilizing equipment at the plurality of line amplifiers to isolate the plurality of sub- sections from one another (FIG. 7: amplifiers 74 in the nodes 56 isolating the sub-sections); and
performing measurements of spans for the parallelized optical link calibration in some or all of the plurality of sub-sections at a same time (FIG. 7: measurement at components 72 and/or OCM 68).
FIG. 7 of Pei is reproduced for reference.
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FIG. 7 shows that the optical section 50 having plural spans connecting the OADM nodes 52, 54 via the amplifiers 74 in node 56. Pei teaches to measure optical signals to characterize the section 50 of the network. See:
[0037] FIG. 7 is a network diagram of an optical section 50 with associated equipment for providing an in-situ nonlinear skirt measurement. The optical section 50 is a segment in an optical network between Optical Add/Drop Multiplexer (OADM) nodes 52, 54. The optical section 50 can be referred to as an Optical Multiplex Section (OMS), and one aspect of each optical section 50 is the spectral load is identical over the entire section. A real implementation of an optical network can include multiple optical sections 50 in a mesh, ring, linear, hub and spoke, etc. architecture. The in-situ nonlinear skirt measurement can be performed on a per optical section basis. The optical section 50 can also include intermediate optical line amplifier nodes 56. Further, a practical implementation of the optical section 50 includes two optical fibers 58, 60 for bidirectional communication. The in-situ nonlinear skirt measurement is performed on each optical fiber 58, 60 separately.
FIG. 7 illustrates amplifiers in node 56. Although this figure illustrates only one amplifier node 56 and only two spans, it would have been obvious that there can be more than one amplifier node and more than two spans in a link. For example, Bortz at FIG. 1 illustrates an optical network with links 18 that include more than one amplifier node 14/30 and more than two spans 12.
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See also:
[0025] The optical paths 12 can include guided and unguided transmission media, such as one or more optical fibers, ribbon fibers, planar devices, and free space devices, and can interconnect the nodes 14 providing optical communication paths through the system 10. Various types of transmission media can be used, such as dispersion shifted fiber ("DSF"), non-dispersion shifted fiber ("NDSF"), non-zero dispersion shifted fiber ("NZDSF"), dispersion compensating fiber ("DCF"), polarization maintaining fiber ("PMF"), single mode fiber ("SMF"), multimode fiber ("MMF"), other types of transmission media, and combinations of transmission media. Furthermore, the transmission media can be doped, such as with erbium, germanium, neodymium, praseodymium, ytterbium, other rare earth elements, other dopants, and mixtures thereof. The paths 12 can carry one or more uni- or bi-directionally propagating optical signals, each including one or more channels or wavelengths. The optical signal channels can be treated individually or as a single group, or they can be organized into two or more wavebands or spectral groups, each containing one or more optical signal channel. The optical signal channels within a spectral group are all treated the same. For example, all optical signal channels in a spectral group are switched in the same manner, and all are dropped at the same locations, even if every optical signal channel in the spectral group is not utilized at every location at which it is dropped. The use of spectral groups to treat groups of channels in the same manner is one way to efficiently manage large numbers of optical signal channels. One or more paths 12 can be provided between nodes 14 and can be connected to protection switching devices and/or other redundancy systems. The optical path 12 between adjacent nodes 14 is typically referred to as a link 18, and the optical path 12 between adjacent components along a link 18 is typically referred to as a span.
In light of this, it would have been obvious that there can be plural amplifier nodes 56 in Pei. In particular, both Pei and Bortz are in the same technical field (e.g., optical communications) and the results would have been predictable (e.g., the additional amplifier nodes will amplify the signals more often and will further partition the link into additional spans).
Calibration.
Pei at FIG. 7 illustrates the link/section 50 including an ASE source 70, OCM 68, and components 72. Pei teaches to generate test signals and to measure signals to characterize the links and the network. See:
[0022] The present disclosure relates to systems and methods for in-situ fiber characterization using nonlinear skirt measurement. The present disclosure characterizes fiber dispersion and nonlinearity based on the spectral shape of an Amplified Stimulated Emission (ASE) signal. Of note, the ASE signal is more like a coherent, dual-polarization modulated signal than a single polarization CW source. The ASE signal can explore all states of polarization which averages these effects resulting in a more stable and accurate measurement. Also, the ASE signal is available from common infrastructure in a photonic line system without requiring additional equipment, and this can be utilized on a per section basis prior to system turn-up. For example, next-generation photonic line systems utilize ASE for channel holders and/or can generate ASE via amplifiers. An ASE source can be shaped by a Wavelength Selective Switch (WSS) at Tx. At a corresponding Rx, the nonlinear product can be characterized by the nonlinear skirt, i.e., spectral shape of the ASE signal. In an example, a two-peak Tx signal spectral shape is designed using an ASE source and transmitted over the fiber. Of note, other shapes are also contemplated such as a one-peak Tx signal. At a corresponding Rx, the nonlinear product can be characterized by center dip depth, i.e., the relative power difference between the signal peak and the valley of the overlap area of the nonlinear skirt between the two peaks. As a result, measurement depends on relative power between the peak and valley of the two-peak signal. Absolute power accuracy and power monitor Wavelength Dependent Loss (WDL) are not critical requirements for the measurement.
This characterization of the fiber can be used to model and optimize performance and better provision the network.
[0024] The accurate characterization of fiber dispersion and nonlinearity will help model the exact link performance, which is crucial for link budget and performance optimization. This is a key part of a “plug and play” approach for optical control. A fiber-type determination is currently a manual procedure and has been shown to be a source of system issues in many networks where there is often mis-provisioned fiber type. This disclosure removes the manual effort of fiber type identification and provisioning and the associated potential manual error. Furthermore, fiber-type does not accurately characterize the fiber. Even within each fiber type, there is a range of dispersion and nonlinear coefficient. It is also common in real systems to have mixed fiber types within a single span. This disclosure gives an appropriate value, averaged over the nonlinear-length, for the key performance parameters which can be used in optical control an optimization resulting in better performance and higher capacity.
[0025] When an optical signal propagates in a nonlinear medium such as optical transmission fiber, its spectrum will be broadened due to the combination of fiber nonlinearity and dispersion. The broadened spectral shape shows a distinct signature for fiber with different characteristics. Consequently, β.sub.2 and γ can be backed out through measurement and then calculated. This disclosure proposes a process that characterizes β.sub.2 and γ by measuring the broadened spectrum of a shaped ASE signal.
As a result, this process calibrates the models of the links and the network, allowing for improved network performance. See also the discussion below under “Performing Measurements”.
Transmit and Receive OADM Nodes.
The OADM nodes 52, 54 are transmit and receive OADM nodes. See:
[0038] The OADM nodes 52, 54 include a Wavelength Selective Switch (WSS) 62 that faces the optical fibers 58, 60. The WSS 62 forms an optical degree that faces the optical fibers 58, 60. In this example, a single degree is illustrated at each of the OADM nodes 52, 54. Of course, practical implementations may include multiple degrees, each facing a different optical section 50. The WSS 62 is configured to add/drop spectrum to/from the degrees and/or locally. Each OADM node 52, 54 includes a post-amplifier 64 on the transmit side and a pre-amplifier 66 on the receive side. The amplifiers 64, 66 can be Erbium-Doped Fiber Amplifiers (EDFAs). Also, Raman amplifiers may be used as well in addition to EDFAs. The OADM nodes 52, 54 also include an Optical Channel Monitor (OCM) 68 (a.k.a. Optical Power Monitor (OPM), etc.) which is an optical receiver connected (e.g., by a tap) to an output of each of the amplifiers 64, 66. The OCM 68 can have two receivers to simultaneously monitor each of the optical fibers 58, 60 or a switch to allow a single receiver to monitor one of the optical fibers 58, 60 at a time.
In other words, the OADM nodes are transmit OADMs when they add signals to the fiber 60 (e.g., transmit signals on the fiber 60 towards another OADM node with the ASE source 70), and the OADM nodes are receive OADMs when they receive a signal from the fibers 60 (e.g., with the OCM 68).
Partitioning the Section/Link.
The amplifier node 56 separates or partitions the section/link 50 into spans with the amplifiers 74 (see FIG. 7). The amplifiers partition the link by taking the signal from one span, changing (amplifying) it, and then putting the new/changed/amplified signal onto the next span.
The amplifier node 56 also measures and performs signal processing on the received signals using the components 72. See:
[0040] Also, the OADM nodes 52, 54 can include other components 72 such as an OTDR, an OSC, a polarimeter, and a processor. Again, the components 72 are in-situ, i.e., part of the OADM nodes 52, 54. In an embodiment, the components 72 can provide a differential delay measurement, an SRS measurement, a fiber 58, 60 effective length (L.sub.eff) measurement, etc. For example, these measurements are described in commonly-assigned U.S. patent application Ser. No. 15/986,396, filed May 22, 2018, and entitled “Optical fiber characterization measurement systems and methods,” the contents of which are incorporated by reference herein. Further, the processor can be used to obtain the measurement data and perform various data analyses described herein. Also, the intermediate optical line amplifier nodes 56 include in-line optical amplifiers 72.
This reception of signals and measurement of signals further partitions the link. As a result, the method of operating the system includes partitioning the system into spans separated with amplifiers and components 72 that perform the measurements and signal processing at each node.
Equipment to Isolate the Subsections.
As discussed above under “Partitioning”, Pei teaches the use of amplifiers 74 in node 56 to partition or isolate the subsections of the link between the OADM nodes 52, 54. Pei also teaches equipment 72, including an OSC, to receive and process the signals.
Performing Measurements.
Pei teaches performing measurement of spans in the subsections. In particular, FIG. 7 illustrates an ASE source 70, OCM, 68, and components 72. See:
[0028] Of note, the present disclosure performs fiber characterization (e.g., fiber type determination, β.sub.2 and γ measurements, etc. based on sending an ASE signal that is spectrally shaped and measuring the received spectral shape, in particular, the nonlinear skirt. In an example, a two-peak signal as shown in FIG. 1B is utilized where an ASE signal from an ASE source is shaped to form the two peaks. The two-peak signal simplifies measurement and post-processing by providing a relative measurement between the peak and valley of the two peaks. Those of ordinary skill in the art will appreciate it is possible to characterize fiber based on the nonlinear skirt shape of a one-peak signal as shown in FIG. 1A based on LMS fit of the shape of the nonlinear skirt. Further, the present disclosure contemplates other shapes including multiple peaks.
FIG. 7 also illustrates that each node 52, 54, 56 has components 72, and Pei teaches that these components can measure and perform signal processing on the received signals. See:
[0040] Also, the OADM nodes 52, 54 can include other components 72 such as an OTDR, an OSC, a polarimeter, and a processor. Again, the components 72 are in-situ, i.e., part of the OADM nodes 52, 54. In an embodiment, the components 72 can provide a differential delay measurement, an SRS measurement, a fiber 58, 60 effective length (L.sub.eff) measurement, etc. For example, these measurements are described in commonly-assigned U.S. patent application Ser. No. 15/986,396, filed May 22, 2018, and entitled “Optical fiber characterization measurement systems and methods,” the contents of which are incorporated by reference herein. Further, the processor can be used to obtain the measurement data and perform various data analyses described herein. Also, the intermediate optical line amplifier nodes 56 include in-line optical amplifiers 72.
In other words, each of the nodes 52, 54, 56 include the components 72 that provide measurement. Furthermore, the OADM nodes 52, 54 include an optical channel monitor (OCM) 68 that performs measurement. See:
[0041] As described herein, the in-situ fiber nonlinear skirt measurement can be performed with the ASE source 70 and the WSS 62 causing a two-peak signal to be transmitted on the optical fibers 58, 60 and received by the OCM 68. Referring back to FIGS. 1A and 1B, the graphs 10A, 10B illustrate the transmitted spectral shape in line 12. This spectral shape can be achieved through configuration of the ASE source 70 and the WSS 62. The received spectral shape in line 14 is received by the OCM 68 with the corresponding center dip depth 16 a function of the fiber 58, 60.
[0043] For every span i=1˜N in the optical section, starting with i=1 (step 104), the measurement process 100 includes setting the optical amplifiers in a power mode for all spans (this power mode setting only needs to be done once, not necessarily for each iteration) and setting signal launching power at a reference power level, P0.sub.ref for span i, for example P0.sub.ref=15 dBm, and setting the rest of the spans at a much lower launching power, for example (P0.sub.ref−15) (step 106). The measurement process 100 includes reading the OPM 68 at the downstream OADM, and recording the center dip depth of the received signal as Depth.sub.ref|.sub.span=i (step 108). The span count is incremented and steps 104-110 are repeated until the end of the section (step 110).
In other words, the ASE source 70 in node 52 can be used to generate a signal that is measured by the OCM 68 in node 54, and the received signal corresponds to characteristics of the fiber through which it passes. This characterization of the fiber can be used to model and optimize performance and better provision the network. This can be done in parallel, such as by using the OCM 68 in one OADM to characterize one part of the link, and using the OCM 68 in the other OADM to characterize the other part of the link. See also the discussion above under “Calibration” and under “Performing Measurements”.
Regarding claim 2, Pei teaches the method of claim 1, wherein an overall time to complete the parallelized optical link calibration is independent of a number of the plurality of spans.
This claim is rejected under 112(b). However, in the interests of compact prosecution the Examiner notes that measurement devices in each node means that the measurements and analysis is independent of the number of spans. In other words, each node performs a measurement and processing for its span at the same time (see the discussion of claim 1) so that the overall time to complete the measurement and processing is a function of the slowest node, and not the number of spans.
Regarding claim 3, Pei teaches the method of claim 1, wherein the performing measurements are isolated in associated sub-sections without impacting other sub-sections.
As discussed in claim 1, Pei teaches performing measurements in each node. As a result, the measurements are isolated in the node without impacting other sub-section.
Regarding claim 4, Pei teaches the method of claim 1, wherein the equipment at the plurality of line amplifiers to isolate the plurality of sub-sections includes a Variable Optical Attenuator (VOA) and/or an Erbium Doped Fiber Amplifier (EDFA) which is configured to perform isolation.
FIG. 7 illustrates amplifiers 74. Furthermore, Pei teaches that the amplifiers 64, 66 in nodes 52, 54 can be EDFAs. See:
[0038] The OADM nodes 52, 54 include a Wavelength Selective Switch (WSS) 62 that faces the optical fibers 58, 60. The WSS 62 forms an optical degree that faces the optical fibers 58, 60. In this example, a single degree is illustrated at each of the OADM nodes 52, 54. Of course, practical implementations may include multiple degrees, each facing a different optical section 50. The WSS 62 is configured to add/drop spectrum to/from the degrees and/or locally. Each OADM node 52, 54 includes a post-amplifier 64 on the transmit side and a pre-amplifier 66 on the receive side. The amplifiers 64, 66 can be Erbium-Doped Fiber Amplifiers (EDFAs). Also, Raman amplifiers may be used as well in addition to EDFAs. The OADM nodes 52, 54 also include an Optical Channel Monitor (OCM) 68 (a.k.a. Optical Power Monitor (OPM), etc.) which is an optical receiver connected (e.g., by a tap) to an output of each of the amplifiers 64, 66. The OCM 68 can have two receivers to simultaneously monitor each of the optical fibers 58, 60 or a switch to allow a single receiver to monitor one of the optical fibers 58, 60 at a time.
FIG. 7 also illustrates amplifiers 74 in the node 56. Pei does not specify the type of amplifier in node 56, but it would have been obvious that those amplifiers 74 can be of a known type (e.g., the EDFA).
Regarding claim 5, Pei teaches the method of claim 1, wherein the performing measurements includes generating amplified spontaneous emission (ASE) in a current sub-section or in an upstream sub-section and measuring received ASE in the current sub-section (FIG. 7: ASE source 70).
See also:
[0041] As described herein, the in-situ fiber nonlinear skirt measurement can be performed with the ASE source 70 and the WSS 62 causing a two-peak signal to be transmitted on the optical fibers 58, 60 and received by the OCM 68. Referring back to FIGS. 1A and 1B, the graphs 10A, 10B illustrate the transmitted spectral shape in line 12. This spectral shape can be achieved through configuration of the ASE source 70 and the WSS 62. The received spectral shape in line 14 is received by the OCM 68 with the corresponding center dip depth 16 a function of the fiber 58, 60.
In other words, nodes 52, 54 include ASE sources 70 that generate ASE that is used for signal measurement.
Regarding claim 8, Pei teaches the method of claim 5, wherein the generating ASE includes full-band ASE for calibrations using full-band ASE without a specific shape requirement.
It would have been obvious that, in situations where no specific spectral shape is required, an unfiltered or unshaped ASE signal will be used. In other words, it would have been obvious to one of ordinary skill that unneeded components or process steps can be eliminated.
Regarding claim 9, Pei teaches the method of claim 5, wherein the generating ASE includes generating the ASE (FIG. 7: ASE source 70) and spectrally shaping the ASE via a waveshaping device (FIG. 7: WSS 62) for calibrations with specific spectral shape requirements where, at an end of the current sub-section, an Optical Channel Monitor (OCM) is configured to detect a change in the ASE's shape (FIG. 7: OCM 68).
Pei teaches the use of an ASE source (see claim 5) and to spectrally shape the ASE signal. See:
[0028] Of note, the present disclosure performs fiber characterization (e.g., fiber type determination, β.sub.2 and γ measurements, etc. based on sending an ASE signal that is spectrally shaped and measuring the received spectral shape, in particular, the nonlinear skirt. In an example, a two-peak signal as shown in FIG. 1B is utilized where an ASE signal from an ASE source is shaped to form the two peaks. The two-peak signal simplifies measurement and post-processing by providing a relative measurement between the peak and valley of the two peaks. Those of ordinary skill in the art will appreciate it is possible to characterize fiber based on the nonlinear skirt shape of a one-peak signal as shown in FIG. 1A based on LMS fit of the shape of the nonlinear skirt. Further, the present disclosure contemplates other shapes including multiple peaks.
Pei also teaches that the wave shaper can be a WSS. See:
[0022] The present disclosure relates to systems and methods for in-situ fiber characterization using nonlinear skirt measurement. The present disclosure characterizes fiber dispersion and nonlinearity based on the spectral shape of an Amplified Stimulated Emission (ASE) signal. Of note, the ASE signal is more like a coherent, dual-polarization modulated signal than a single polarization CW source. The ASE signal can explore all states of polarization which averages these effects resulting in a more stable and accurate measurement. Also, the ASE signal is available from common infrastructure in a photonic line system without requiring additional equipment, and this can be utilized on a per section basis prior to system turn-up. For example, next-generation photonic line systems utilize ASE for channel holders and/or can generate ASE via amplifiers. An ASE source can be shaped by a Wavelength Selective Switch (WSS) at Tx. At a corresponding Rx, the nonlinear product can be characterized by the nonlinear skirt, i.e., spectral shape of the ASE signal. In an example, a two-peak Tx signal spectral shape is designed using an ASE source and transmitted over the fiber. Of note, other shapes are also contemplated such as a one-peak Tx signal. At a corresponding Rx, the nonlinear product can be characterized by center dip depth, i.e., the relative power difference between the signal peak and the valley of the overlap area of the nonlinear skirt between the two peaks. As a result, measurement depends on relative power between the peak and valley of the two-peak signal. Absolute power accuracy and power monitor Wavelength Dependent Loss (WDL) are not critical requirements for the measurement.
It would have been obvious that the spectral shaping is performed by a spectral shaping device (e.g., a WSS).
Regarding the OCM, see:
[0041] As described herein, the in-situ fiber nonlinear skirt measurement can be performed with the ASE source 70 and the WSS 62 causing a two-peak signal to be transmitted on the optical fibers 58, 60 and received by the OCM 68. Referring back to FIGS. 1A and 1B, the graphs 10A, 10B illustrate the transmitted spectral shape in line 12. This spectral shape can be achieved through configuration of the ASE source 70 and the WSS 62. The received spectral shape in line 14 is received by the OCM 68 with the corresponding center dip depth 16 a function of the fiber 58, 60.
[0043] For every span i=1˜N in the optical section, starting with i=1 (step 104), the measurement process 100 includes setting the optical amplifiers in a power mode for all spans (this power mode setting only needs to be done once, not necessarily for each iteration) and setting signal launching power at a reference power level, P0.sub.ref for span i, for example P0.sub.ref=15 dBm, and setting the rest of the spans at a much lower launching power, for example (P0.sub.ref−15) (step 106). The measurement process 100 includes reading the OPM 68 at the downstream OADM, and recording the center dip depth of the received signal as Depth.sub.ref|.sub.span=i (step 108). The span count is incremented and steps 104-110 are repeated until the end of the section (step 110).
Regarding claim 10, Pei teaches the method of claim 5, wherein the measuring is via one of a Raman amplifier and an Optical Channel Monitor (OCM) (FIG. 7: OCM 68).
Regarding claim 11, Pei teaches an optical line system comprising:
a transmit Optical Add/Drop Multiplexer (OADM) (FIG. 7: OADM 52);
a receive OADM (FIG. 7: OADM 54); and
a plurality of line amplifiers located between the transmit OADM and the receive OADM, each of line amplifier of the plurality of line amplifiers including an optical amplifier (FIG. 7: amps 74);
wherein the transmit OADM, the plurality of line amplifiers, and the receive OADM form an optical section having a plurality of spans (FIG. 7: plurality of spans defined by nodes 52, 54, 56), and
wherein the transmit OADM, the plurality of line amplifiers, and the receive OADM are partitioned in a plurality of sub-sections each including one or more spans of the plurality of spans (FIG. 7: plurality of spans defined by nodes 52, 54, 56) for parallelized optical link calibration that includes
utilization of equipment at the plurality of line amplifiers to isolate the plurality of sub-sections from one another (FIG. 7: amplifiers 74 in the nodes 56 isolating the sub-sections), and
measurements of spans for the parallelized optical link calibration in some or all of the plurality of sub-sections at a same time (FIG. 7: measurement at components 72 and/or OCM 68).
This claim is an apparatus that generally corresponds to the method of claim 1. See claim 1 for a more detailed discussion of the art.
Regarding the amplifiers being optical amplifiers, this would have been obvious. For example, Bortz teaches that optical amplifiers were known in optical communication systems. For example, FIG. 1 of Bortz illustrates an optical communication system including nodes 14 connected by links 18 including plural spans 12, with amplifiers separating the spans.
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Furthermore, it teaches that the amplifiers can be optical amplifiers. See:
[0040] The optical amplifiers 30 can be used to provide signal gain, such as to overcome attenuation, and can be deployed proximate to other optical components, such as in nodes 14, as well as along the optical communications paths 12. The optical amplifiers 30 can include concentrated/lumped amplification and/or distributed amplification, and can include one or more stages. The optical amplifier can include, for example, doped (e.g. erbium, neodymium, praseodymium, ytterbium, other rare earth elements, other dopants, and mixtures thereof) and/or non-linear interaction amplifiers (e.g., Raman amplifiers, Brillouin amplifiers, etc.), and can be locally and/or remotely pumped with optical energy. The optical amplifiers 30 can also include other types of amplifiers 30, such as semiconductor amplifiers. Two or more amplifiers 30 may be co-located and concatenated to provide additional flexibility.
It would have been obvious that the amplifiers in Pei can be implemented in a known manner, such as optical amplifiers as taught in Bortz. In particular, both are in the same technical field (e.g., optical communications) and the results would have been predictable (e.g., the optical amplifiers will operate as amplifiers).
Regarding claim 12, Pei teaches the optical line system of claim 11, wherein an overall time to complete the parallelized optical link calibration is independent of a number of the plurality of spans.
This claim corresponds to method claim 2 and is rejected for the reasons set forth in the rejection of claim 2.
Regarding claim 13, Pei teaches the optical line system of claim 11, wherein the measurements of spans include measuring each span in a sub-set of selected sub-sections without impacting other sub- sections.
This claim corresponds to method claim 3 and is rejected for the reasons set forth in the rejection of claim 3.
Regarding claim 14, Pei teaches the optical line system of claim 11, wherein the equipment at the plurality of line amplifiers to isolate the plurality of sub-sections includes a Variable Optical Attenuator (VOA) and/or an Erbium Doped Fiber Amplifier (EDFA) which is configured to perform isolation
This claim corresponds to method claim 4 and is rejected for the reasons set forth in the rejection of claim 4.
Regarding claim 15, Pei teaches the optical line system of claim 11, wherein the measurements include generating amplified spontaneous emission (ASE) in a current sub-section or in an upstream sub- section and measuring received ASE in the current sub-section.
This claim corresponds to method claim 5 and is rejected for the reasons set forth in the rejection of claim 5.
Regarding claim 18, Pei teaches the optical line system of claim 15, wherein the generating ASE includes full-band ASE for calibrations using full-band ASE without a specific shape requirement.
This claim corresponds to method claim 8 and is rejected for the reasons set forth in the rejection of claim 8.
Regarding claim 19, Pei teaches the optical line system of claim 15, wherein the generating ASE includes generating the ASE and spectrally shaping the ASE via a waveshaping device for the calibrations with specified shaped ASE as source signals where, at an end of the current sub-section, an Optical Channel Monitor (OCM) is configured to detect a change in the ASE's shape.
This claim corresponds to method claim 9 and is rejected for the reasons set forth in the rejection of claim 9.
Regarding claim 20, Pei teaches the optical line system of claim 15, wherein the measuring is via one of a Raman amplifier and an Optical Channel Monitor (OCM).
This claim corresponds to method claim 10 and is rejected for the reasons set forth in the rejection of claim 10.
Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over the art as applied to claim 5 above, and further in view of US 7,450,288 (Kikuchi).
Regarding claim 6, Pei teaches the method of claim 5, wherein the generating ASE is via one of an Erbium Doped Fiber Amplifier (EDFA), a semiconductor optical amplifier (SOA), or a Raman amplifier.
Pei teaches an ASE source (e.g., see FIG. 7 and the discussion of claim 1). Furthermore, it was known that EDFA and Raman amps can be used as an ASE source. See, for example, Kikuchi at the paragraph spanning cols 16-17:
(70) When the broadband optical source 146, such as an LED as in this embodiment, is used as the control optical source, there is given advantages that the frequency band of the optical source is widened, the optical source becomes less prone to arise an adverse effect, such as interfering with the signal light, and it is insusceptible to influences of reflection of optical parts and interference because of low coherency. Thus, as a low-interference control optical source, there are known an SLD (Super Luminescent Diode), an ASE optical source that uses amplified spontaneous emission (ASE) of an optical fiber amplifier, such as an EDFA and a Raman amplifier, a Fabry-Perot type multimode laser, etc. These optical sources can be widely applicable. Moreover, even a DFB laser optical source with high coherency and a Fabry-Perot type multimode laser can be used if their spectral widths are widened to effect decrease in coherency by modulating lasers with a sinusoidal wave or a noise signal intentionally or by letting them oscillate autonomously at specific modes by means of a technique of optical feedback etc.
It would have been obvious that the ASE source of Pei can be implemented in a known manner, such as with an EDFA or Raman amp as taught in Kikuchi. In particular, both are in the same technical field (e.g., optical communications) and the results would have been predictable.
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over the art as applied to claim 5 above, and further in view of US 2024/0178630 (Walasik).
Regarding claim 7, Walasik teaches the method of claim 5, wherein the generating ASE is via a first line amplifier having a first amplifier configured to create full-band ASE and a second line amplifier having a second amplifier configured to launch the full-band ASE at a specified power and tilt.
Walasik at FIG. 4 illustrates an ASE source including a first amp stage 11 and a second amplifier stage 41.
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[0036] FIG. 4 illustrates another embodiment of the present invention, identified as ASE source 40. In this case, ASE source 40 can be thought of as an extension of ASE source 10 of FIG. 1; in particular with the addition of an amplifier stage 41 that is used to increase the output power of the ASE created within an ASE-generating stage 11. Elements of ASE 40 that are identical (substantially identical) to those of ASE 10 are identified by the same reference numerals. Here, however, the ASE output produced by the interaction of the pump beam and Tm-dopant within TDF 12 is identified as ASE.sub.inter, an “inter-stage” ASE output.
[0037] As shown in FIG. 4, ASE.sub.inter is thereafter applied as an input to amplifier stage 41 and in particular to a second section of TDF, referred to as TDF 42. In this embodiment, amplifier stage 41 can be thought of as a thulium-doped fiber amplifier (i.e., TDFA), where the input signal ASE.sub.inter is amplified by an applied pump beam to impart additional gain to the created ASE and thereby produce a high-power ASE output.
The ASE source 40 has the same structure as the second stage amplifier 41. In particular, both have TDF fiber 12, 42 which is pumped from a shared pump source 14. Therefore, the ASE source 40 is an amplifier (i.e., a TDFA like amplifier 41; see [0037]).
Regarding the ASE being “full band”, this embodiment does not use a filter to restrict the spectrum of the ASE source 11. Therefore, it is “full band” ASE. Contrast this with FIG. 14 which uses a BPF to limit the ASE spectrum.
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[0058] In some applications, it may be useful to shape the ASE spectrum to exhibit a particular profile (e.g., square, Gaussian, triangular, etc.). Additionally, controlling the wavelength range of the generated emission may be necessary. An embodiment of the present invention as shown in FIG. 14 is useful for this purpose. In particular, an ASE source 120 is configured to include a bandpass filter (BPF) 122 disposed between ASE-generating stage 11 and amplifier stage 41. The bandwidth of filter 122 can be configured to be anywhere in the range from a fraction of a nm (<<1 nm) to several nm (>>10 nm). The inclusion of filter 122 at this point along the signal path limits the ASE energy distribution and selects a certain portion of the ASE spectrum produced by ASE-generating stage 11 as the input for amplifier stage 41. As represented here, the ASE.sub.inter output from ASE-generating stage 11 is filtered by passing through BPF 122, creating an output ASE.sub.fil that is applied as an input to amplifier stage 41. By shaping the emission spectrum prior to amplification, the power generated within amplifier stage 41 is directed into only the usable bandwidth, thus forming an ASE source that exhibits more power over the defined bandwidth. Filter 122 may also extend the bandwidth of the ASE source by seeding a shorter wavelength band (e.g., 1760 nm) from ASE-generating stage 11 into amplifier stage 41. Filter 122 may be fixed or tunable across the amplified spectrum. Additionally, when used as a component of a polarization-maintaining ASE source, filter 122 is required to also maintain the desired polarization state. In a more general manner, filter 122 may take the form of an ASE WDM filter with N (N>2) outputs with some of different spectral widths that are used to seed some of the different amplifier stages.
Regarding the second amplifier launching at “a specified power and tilt”, the second amp 41 launches at the power and tilt specified by the particular amplifier used (i.e., based on the characteristics of the TDF used and the pump light). The Examiner notes that the claim does not limit this power or tilt to any particular values or range.
Claim(s) 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over the art as applied to claim 15 above, and further in view of US 7,450,288 (Kikuchi).
Regarding claim 16, Pei teaches the optical line system of claim 15, wherein the generating ASE is via one of an Erbium Doped Fiber Amplifier (EDFA), semiconductor optical amplifier (SOA), or Raman amplifier.
This claim corresponds to method claim 6 and is rejected for the reasons set forth in the rejection of claim 6.
Claim(s) 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over the art as applied to claim 15 above, and further in view of US 2024/0178630 (Walasik).
Regarding claim 17, Walasik teaches the optical line system of claim 15, wherein the generating ASE is via a first line amplifier having a first amplifier configured to create full-band ASE and a second line amplifier having a second amplifier configured to launch the full-band ASE at a specified power and tilt.
This claim corresponds to method claim 7 and is rejected for the reasons set forth in the rejection of claim 7.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. US 2004/0075889 (Shin) at FIG. 3 illustrates an ASE source including first and second stage amplifiers 330. 390.
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[0022] FIG. 3 depicts an illustrative embodiment of an unpolarized multi-lambda source in accordance with the principles of the present invention. The unpolarized multi-lambda source includes an optical fiber amplifier 300, a reflector 310, a comb filter 320 and an equalization filter 410. Hereinafter, components will be described according to a sequence of processing ASE light so that the present invention can be readily understood.
[0027] The optical fiber amplifier 300 includes first and second amplifying fibers 330 and 390, first and second pumping sources 350 and 380, first and second wavelength selective couplers 340 and 370, and first and second optical isolators 360 and 400.
[0028] The first amplifying fiber 330 amplifies the optical signal received/inputted from the comb filter 320 and then outputs the amplified optical signal. The first and second amplifying fibers 330 and 390 can employ erbium-doped fibers.
US 2001/0004290 (Lee) is the closest art of record and teaches that it was known to make an ASE source from a two stage EDFA. See:
[0084] The ASE source was two-stage erbium-doped fiber amplifier (EDFA) pumped counter-directionally with laser diode at 1480 nm. The pump power for the first and the second stage of EDFA were 50 mW and 100 mW, respectively. A band pass filter (BPF) with a bandwidth of 9 nm was used at the output end of the EDFA to limit the spectral width of the ASE within one free spectral range (FSR) of the waveguide grating router (WGR). An optical amplifier (AMP1) and an optical variable attenuator (Att.1) were used to control the ASE power injected into the F-P LD. An optical circulator with insertion loss of 0.7 dB separated the injected broadband ASE and the output of the F-P LD. The broadband ASE was sliced spectrally by an WGR with a bandwidth of 0.24 nm and injected into the F-P LD. A conventional F-P LD without an optical isolator was locked by the externally injected narrow-band ASE. The threshold current of the F-P LD was 20 mA. The coupling efficiency of the F-P LD, the rate of power transferred from laser to pig-tailing fiber or vice versa, was approximately 8%. The F-P LD was modulated directly by pseudorandom nonreturn-to-zero data with a length of 2.sup.7-1 at 155 Mb/s and its output was transmitted through conventional single mode fiber (SMF). The transmitted data was amplified by an optical amplfier (AMP2), demultiplexed by another WGR with a bandwidth of 0.32 nm, and received by a PIN photo-detector based receiver to measure the bit error rate (BER) characteristics. The receiver input power was controlled by an optical variable attenuator (Att.2) and measured by an optical power meter (PM). A polarization controller (PC) and a polarizing fiber (PZF) with about 47 dB of polarization extinction ratio are used to improve the extinction ratio of the modulated optical signal.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DARREN WOLF whose telephone number is (571)270-3378. The examiner can normally be reached Monday through Friday, 7:00 AM to 3:00 PM.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, KENNETH N. VANDERPUYE can be reached at 571-272-3078. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/DARREN E WOLF/Primary Examiner, Art Unit 2634