Method and apparatus for detecting an optical tip signal
Patent Information
- Application Number
- CN202510483089.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-17
- Publication Date
- 2026-10-23
AI Technical Summary
[0003]LS技术是一个独立于业务传输，但是复用信息传输通道的一个通信系统，类似于其它的通信技术，它同样会受到光纤中的各种效应的影响，其中最突出的是光纤的色度色散(chromatic dispersion，CD)和受激拉曼散射(stimulated Raman scattering，SRS)效应，导致传输距离受限，检测精度较低
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Figure CN122969654A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of optical communication technology, and in particular to a method and apparatus for detecting optical modulation signals. Background Technology
[0002] Light sensor (LS) technology monitors a single channel by loading low-frequency (below tens of megahertz (MHz)) pilot tone onto a high-speed (above several gigahertz (GHz)) optical wavelength channel. Utilizing frequency division multiplexing (FDM) technology, different LS pilots are loaded onto different wavelengths, enabling multi-channel monitoring. At the LS signal transmitting end, loading is implemented using an optical digital signal processor (ODSP); at the LS signal receiving end, signal analysis is performed using a photodetector (PD) and a specially designed chip.
[0003] Fiber optics (LS) technology is a communication system that is independent of service transmission but reuses the information transmission channel. Similar to other communication technologies, it is also affected by various effects in optical fibers, most notably chromatic dispersion (CD) and stimulated Raman scattering (SRS), which limit transmission distance and reduce detection accuracy. Current solutions address this by adding beam splitters, such as using odd-even wavelength division multiplexing (OWDM), but these methods are costly and have low integration. Summary of the Invention
[0004] This application provides a method and apparatus for detecting optically tuned signals, which can improve the detection speed and transmission distance of optically tuned signals.
[0005] In a first aspect, embodiments of this application provide a wavelength selective switch (WSS), including an input port, multiple output ports, a detection port, and a silicon-based liquid crystal (LCoS). The input port is used to receive an incident light beam carrying a modulation signal. The LCoS is used to load a phase grating to modulate the incident light beam, such that the modulated incident light beam diffracts to the detection port and at least one of the multiple output ports. The detection port is used to detect the optical modulation signal carried in the input light beam. The phase grating controls the spectral width of the optical signal diffracted by the LCoS to the detection port to be within a set spectral width range. A first transmission distance supported by the set spectral range is greater than a second transmission distance, and the second transmission distance is the maximum transmission distance supported by the spectral width greater than the maximum spectral width within the set spectral range. The spectral width of the incident light beam is greater than the maximum spectral width.
[0006] For example, the spectral width of the detection port is related to the required transmission distance of the system. Alternatively, the spectral width range can be set to be related to the required transmission distance of the system.
[0007] During transmission, the transmission distance of the modulated signal is affected by chromatic dispersion, and the wider the spectral width, the greater the impact of dispersion. This application's embodiment combines the flexible spectral adjustment capability of LCOS to control the spectral width of the optical signal transmitted to the detection port, thereby suppressing dispersion and reducing the impact of SRS, thus increasing the transmission distance.
[0008] In one possible implementation, the spectral range of the incident beam is [P1, P2];
[0009] The spectral range of the optical signal output from the detection port is [P1, P1+W], where W is the spectral width of the optical signal output from the detection port; or,
[0010] The spectral range of the optical signal output from the detection port is [P2-W, P2], where W is the spectral width of the optical signal output from the detection port; or,
[0011] The spectral range of the optical signal output from the detection port is [(P1+P2-W) / 2, (P1+P2+W) / 2], where W is the spectral width of the optical signal output from the detection port.
[0012] In one possible implementation, the incident beam comprises optical signals of N wavelengths, where N is an integer greater than 1; the phase grating controls the optical signals diffracted by the LCoS to the detection port to include the optical signals of the N wavelengths.
[0013] In the above scheme, signals of all wavelengths are output through the detection port, which can detect the modulation signal of any wavelength of optical signal.
[0014] In one possible implementation, the optical power of the N wavelengths of the optical signal output from the detection port satisfies the flatness requirement.
[0015] In the above scheme, the optical power of the optical signal output from the detection port meets the flatness requirement, which can reduce the problem of low signal-to-noise ratio caused by low power signals due to uneven signal power, thereby reducing detection time and improving detection efficiency.
[0016] In one possible implementation, the optical power of all N wavelengths of optical signals output from the detection port is less than or equal to the optical power of the first wavelength in the incident beam, where the first wavelength is the wavelength of the optical signal with the lowest optical power among the N wavelengths of optical signals included in the incident beam.
[0017] The above implementation method can perform power balancing based on the minimum optical power among the optical powers of the N wavelengths of optical signals included in the incident beam.
[0018] Secondly, embodiments of this application provide a wavelength selective switch (WSS), including an input port, multiple output ports, a detection port, and a silicon-based liquid crystal (LCoS). The input port is used to receive an incident light beam carrying a peak-adjustment signal. The incident light beam includes optical signals of N wavelengths, where N is a positive integer. The LCoS is used to load a phase grating to modulate the incident light beam, such that the modulated incident light beam diffracts to the detection port and at least one of the multiple output ports. The detection port is used to detect the optical peak-adjustment signal. The phase grating controls the optical signals diffracted by the LCoS to the detection port to include the optical signals of the N wavelengths, and the optical power of the optical signals of the N wavelengths output by the detection port meets the flatness requirement.
[0019] In the above scheme, the optical power of the optical signal output from the detection port meets the flatness requirement, which can reduce the problem of low signal-to-noise ratio caused by low power signals due to uneven signal power, thereby reducing detection time and improving detection efficiency.
[0020] In one possible implementation, the optical power of all N wavelengths of optical signals output from the detection port is less than or equal to the optical power of the first wavelength in the incident beam, where the first wavelength is the wavelength of the optical signal with the lowest optical power among the N wavelengths of optical signals included in the incident beam.
[0021] Thirdly, embodiments of this application provide a device for detecting optical modulation signals, comprising a WSS and an optical sensor LS as described in either the first or second aspect, wherein the LS is connected to the detection port of the WSS; the LS is used to detect modulation signals from the optical signals output from the detection port.
[0022] Fourthly, embodiments of this application provide a method for detecting an optically tuned signal. The detection method can be implemented by a control device or a detection device. A phase grating is loaded onto a silicon-based liquid crystal (LCoS) in a wavelength selective switch (WSS) to modulate the incident beam of the WSS, causing the modulated incident beam to diffract onto a detection port of the WSS and at least one of multiple output ports. The phase grating controls the spectral width of the optical signal diffracted by the LCoS to the detection port to be within a set spectral width range. The set spectral range supports a first transmission distance greater than a second transmission distance, where the second transmission distance is a transmission distance supported by a spectral width greater than the maximum spectral width within the set spectral range. The spectral width of the incident beam is greater than the maximum spectral width. The tuned signal is detected in the optical signal output from the detection port.
[0023] The beneficial effects of the fourth aspect can be found in the relevant description of the first aspect, and will not be repeated here.
[0024] In one possible implementation, the spectral range of the incident beam is [P1, P2];
[0025] The spectral range of the optical signal output from the detection port is [P1, P1+W], where W is the spectral width of the optical signal output from the detection port; or,
[0026] The spectral range of the optical signal output from the detection port is [P2-W, P2], where W is the spectral width of the optical signal output from the detection port; or,
[0027] The spectral range of the optical signal output from the detection port is [(P1+P2-W) / 2, (P1+P2+W) / 2], where W is the spectral width of the optical signal output from the detection port.
[0028] In one possible implementation, the incident beam comprises optical signals of N wavelengths, where N is an integer greater than 1; the phase grating controls the optical signals output by the LCoS from the detection port to include the optical signals of the N wavelengths.
[0029] In one possible implementation, the optical power of the N wavelengths of the optical signal output from the detection port satisfies the flatness requirement.
[0030] In one possible implementation, the optical power of all N wavelengths of optical signals output from the detection port is less than or equal to the optical power of the first wavelength in the incident beam, where the first wavelength is the wavelength of the optical signal with the lowest optical power among the N wavelengths of optical signals included in the incident beam.
[0031] Fifthly, embodiments of this application provide a method for detecting an optically tuned signal. The detection method can be implemented by a control device or a detection apparatus. The detection method includes: loading a phase grating onto a silicon-based liquid crystal (LCoS) in a wavelength selective switch (WSS) to modulate the incident beam of the WSS, such that the modulated incident beam diffracts onto a detection port of the WSS and at least one of multiple output ports; the incident beam includes optical signals of N wavelengths, where N is a positive integer; the phase grating controls the optical signals diffracted by the LCoS to the detection port to include the N wavelengths, and the optical power of the N wavelengths of optical signals output from the detection port meets a flatness requirement. An optically tuned signal is detected in the optical signals output from the detection port.
[0032] In one possible implementation, the optical power of all N wavelengths of optical signals output from the detection port is less than or equal to the optical power of the first wavelength in the incident beam, where the first wavelength is the wavelength of the optical signal with the lowest optical power among the N wavelengths of optical signals included in the incident beam.
[0033] Sixthly, embodiments of this application provide a method for detecting optically tuned signals, which can be implemented by a WSS.
[0034] The WSS receives an incident light beam; the incident light beam carries a modulation signal. The WSS has a phase grating loaded on a silicon-based liquid crystal (LCoS) to modulate the incident light beam, causing the modulated beam to diffract to a detection port and at least one of multiple output ports. The phase grating controls the spectral width of the light signal diffracted by the LCoS to the detection port to be within a set spectral width range. The set spectral range supports a first transmission distance greater than a second transmission distance, where the second transmission distance is greater than the transmission distance supported by the spectral width of the maximum spectral width within the set spectral range. The spectral width of the incident light beam is greater than the maximum spectral width. The detection port is used to detect the modulation signal.
[0035] The beneficial effects of the sixth aspect can be found in the relevant description of the first aspect, and will not be repeated here.
[0036] In one possible implementation, the spectral range of the incident beam is [P1, P2];
[0037] The spectral range of the optical signal output from the detection port is [P1, P1+W], where W is the spectral width of the optical signal output from the detection port; or,
[0038] The spectral range of the optical signal output from the detection port is [P2-W, P2], where W is the spectral width of the optical signal output from the detection port; or,
[0039] The spectral range of the optical signal output from the detection port is [(P1+P2-W) / 2, (P1+P2+W) / 2], where W is the spectral width of the optical signal output from the detection port.
[0040] In one possible implementation, the incident beam comprises optical signals of N wavelengths, where N is an integer greater than 1; the phase grating controls the optical signals output by the LCoS from the detection port to include the optical signals of the N wavelengths.
[0041] In one possible implementation, the optical power of the N wavelengths of the optical signal output from the detection port satisfies the flatness requirement.
[0042] In one possible implementation, the optical power of all N wavelengths of optical signals output from the detection port is less than or equal to the optical power of the first wavelength in the incident beam, where the first wavelength is the wavelength of the optical signal with the lowest optical power among the N wavelengths of optical signals included in the incident beam.
[0043] Seventhly, embodiments of this application provide a method for detecting an optically tuned top signal, which can be implemented using a WSS (Wireless Surface Mount System). The detection method includes:
[0044] The WSS receives the incident light beam;
[0045] The WSS has a phase grating loaded on a silicon-based liquid crystal LCoS to modulate the incident light beam, causing the modulated incident light beam to diffract to the detection port and at least one of multiple output ports of the WSS. The incident light beam includes optical signals of N wavelengths, where N is a positive integer. The phase grating controls the optical signals diffracted by the LCoS to the detection port to include the N wavelengths, and the optical power of the N wavelengths of optical signals output by the detection port meets the flatness requirement. The detection port is used to detect the modulation signal.
[0046] In one possible implementation, the optical power of all N wavelengths of optical signals output from the detection port is less than or equal to the optical power of the first wavelength in the incident beam, where the first wavelength is the wavelength of the optical signal with the lowest optical power among the N wavelengths of optical signals included in the incident beam.
[0047] Based on the implementations provided in the above aspects, this application can be further combined to provide more implementations. Attached Figure Description
[0048] Figure 1 This is a schematic diagram illustrating the application of LS in an optical system to which the embodiments of this application apply;
[0049] Figure 2 This is a schematic diagram of an application that uses a beam splitter to detect LS pilot signals.
[0050] Figure 3 A schematic diagram illustrating the effects of dispersion and SRS;
[0051] Figure 4 A schematic diagram of LS detection using the odd-even wavelet detection method;
[0052] Figure 5 This is a schematic diagram of a possible WSS structure;
[0053] Figure 6 A schematic diagram of another possible WSS structure;
[0054] Figure 7 A schematic diagram of the structure of a WSS provided in an embodiment of this application;
[0055] Figure 8 This is a schematic diagram of WSS-based signal transmission provided in an embodiment of this application;
[0056] Figure 9 This is a schematic diagram illustrating the dispersion suppression effect provided in an embodiment of this application;
[0057] Figure 10 A schematic diagram of the detection device for the optical modulation signal provided in the embodiments of this application;
[0058] Figure 11 A schematic flowchart of the method for detecting the optically tuned top signal provided in the embodiments of this application;
[0059] Figure 12 This is a schematic diagram illustrating the impact of power unevenness on the system, provided in an embodiment of this application.
[0060] Figure 13 A schematic diagram of the output optical power provided in the embodiments of this application;
[0061] Figure 14 This application provides a schematic flowchart of another method for detecting optically tuned signals.
[0062] Figure 15 This application provides a schematic flowchart of another method for detecting optically tuned signals. Detailed Implementation
[0063] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.
[0064] In the description of this application, unless otherwise stated, "multiple" refers to two or more. Additionally, " / " indicates that the related objects are in an "or" relationship; for example, A / B can represent A or B. "And / or" in this application merely describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone, where A and B can be singular or plural. Furthermore, to facilitate a clear description of the technical solutions of the embodiments of this application, the terms "first" and "second" are used in the embodiments to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that "first" and "second" are not necessarily different. It should also be noted that, unless specifically stated, the specific description of some technical features in one embodiment can also be used to explain the corresponding technical features mentioned in other embodiments.
[0065] Light sensor (LS) technology enables single-channel monitoring by loading low-frequency (below tens of megahertz (MHz)) pilot tone modulation onto high-speed (above several gigahertz (GHz)) optical wavelength channels. On one hand, the optical power of the signal can be calculated by detecting the amplitude of the modulated pilot tone; on the other hand, the modulation data can be used to implement along-path overhead functions for channel identification, tracking, and other applications. Utilizing frequency division multiplexing (FDM) technology, different LS pilot tones can be loaded onto different wavelengths, enabling single-wavelength monitoring of a wavelength division multiplexing system without relying on optical filters. This offers advantages such as high detection speed, high integration, and low cost.
[0066] In some implementations, a top-modulation signal can be used as the LS pilot. A top-modulation signal, in a wavelength division multiplexing (WDM) system, refers to a low-frequency sine or cosine modulated signal with a small amplitude superimposed on each wavelength. When these signals are superimposed on the optical wavelength, they modulate the top of the optical wavelength, hence the name top-modulation signal. The information carried by the top-modulation signal may include one or more of the following: wavelength information, ROADM (Reconfigurable Optical Add-Drop Multiplexer) node information of the transmitting end, its domain, and destination ROADM node information.
[0067] See Figure 1The diagram illustrates the application of LS in an optical system, as described in this embodiment. At the transmitting end of the LS pilot signal, the tuning signal is loaded via an optical digital signal processor (ODSP) within the optical transponder unit (OTU). Tuning signals can be detected at various locations along the main optical path, including the lower and upper points. For example... Figure 1 The location detection point of the middle triangle.
[0068] In one possible implementation, to achieve LS detection, a beam splitter is added at the detection point to detect the LS pilot signal. For example, see... Figure 2 As shown. However, dispersion and SRS effects in optical fibers affect signal transmission distance. See also Figure 3 As shown in (a), the LS pilot exists across the entire spectrum, therefore the LS pilot signal is also affected by dispersion and SRS effects. Dispersion causes signals of different wavelengths within the spectrum to superimpose in opposite directions, leading to signal fading. The higher the pilot frequency, the more pronounced the attenuation; see [reference needed]. Figure 3 As shown in (c). Figure 3 Figure (b) illustrates the SRS effect in multi-wavelength channel signals. When more than one wavelength channel exists, energy is transferred from shorter wavelengths to longer wavelengths due to the SRS effect. Several factors influence SRS, including signal power, the number of spans, the number of channels, channel distribution, and fiber type. For example, in the C-band, SRS crosstalk is roughly proportional to the frequency difference between two channels. Low-frequency modulation on one channel also propagates to another. Due to this SRS effect, the detected signal power also includes contributions from other channels. For example, channel λ1 has low-frequency modulation f1. Due to SRS, f1 appears in channels λ2 and λ3. The error caused by SRS crosstalk in multi-span systems can be greater than 5 dB, rendering power monitoring useless. The error can also be so large that even channel detection is incorrect.
[0069] One possible implementation involves using an odd-even wavelet detection method to reduce the impact of the SRS effect; see [link to relevant documentation]. Figure 4 As shown, the detection signal is divided into odd and even paths for detection using an interlever (ITL), where PD1 = Signal + SRS_crosstalk, PD2 = SRS_crosstalk, and the detection result = PD1 - PD2. This scheme requires the use of ITL and other splitting devices for wavelength division, which is costly.
[0070] Based on this, embodiments of this application provide a detection scheme for optically tuned signals, which reduces the impact of dispersion and SRS effects on signal transmission distance, and does not require additional beam splitting devices, thereby reducing costs.
[0071] The technical concepts involved in the embodiments of this application will be explained below.
[0072] A wavelength selective switch (WSS) is a flexible optical path adjustment device. Signals of different wavelengths are transmitted to a grating through the input port, which disperses the signals of different wavelengths and transmits them to different areas of a liquid crystal on silicon (LCOS). Different areas are loaded with corresponding phase maps, controlling the transmission of different wavelength signals to different ports, thereby realizing the transmission of different wavelength services.
[0073] The core principle of WSS based on LCOS is to apply different voltages to different pixels of LCoS. Due to the birefringence effect of LCOS liquid crystal, different voltages will correspond to different phase delays, thus forming a structure similar to a blazed grating, which can also be called a phase grating or phase map. Figure 6 A schematic diagram illustrating an example of the structure of the WSS of this application is shown. It should be understood that... Figure 5 This is a schematic diagram of a possible WSS and does not specifically limit the structure of the WSS. Figure 5 As shown, the WSS contains multiple ports, serving as input or output ports for optical signals. After the incident optical signal enters the WSS through the input port, it first needs to be separated into two orthogonal beams by a polarization processing unit. Then, the polarization state of one of the beams is rotated to align the deflection states of the two beams with the operating polarization state of the LCOS. If a polarization-independent LCOS is used, a polarization processing unit is not required; see [link to relevant documentation]. Figure 6As shown, the polarization-converted optical signal is incident on a grating through a switching lens. The grating is a dispersive element used to decompose the optical signal into optical signals with different wavelengths and transmit them to the LCOS. The phase grating formed in the LCOS is not the same as the optical grating; the optical grating is a physical entity, while the phase grating formed in the LCOS is an equivalent grating. Optical signals of different wavelengths exit from the grating at different angles and are incident on different regions of the LCOS after passing through the dispersive lens. By adjusting the grayscale distribution of the grating in different regions of the LCOS, the corresponding wavelengths can be controlled to achieve angular deflection in the port direction perpendicular to the carrier wave. The angle-deflected optical signal is then incident on the switching lens, which offsets the position of the optical signal, coupling it to a specific output port. By controlling the grayscale distribution of the grating in one region of the LCOS, the optical signal incident on that region can be output from different output ports.
[0074] The embodiments of this application can utilize the spectral tunability of WSS based on LCOS to suppress dispersion and SRS effect, thereby improving transmission distance.
[0075] Figure 7 A schematic diagram of the structure of the WSS provided in an embodiment of this application. See also... Figure 7 As shown, the WSS includes an input port, a detection port, multiple output ports, and an LCoS. The input port receives the incident light beam. The LCoS modulates the incident light beam using a phase grating (or phase grating), causing the modulated incident light beam to diffract onto at least one of the multiple output ports and the detection port. The WSS may also include other units or modules, such as a polarization processing unit, a collimation processing unit, a lens, etc., but this embodiment does not specifically limit these features.
[0076] WSS is implemented by loading a phase map onto an LCOS. The input optical signal is transmitted through the corresponding target output port. By designing the phase map loaded onto the LCOS, the input signal can be transmitted to different ports. See also Figure 8 As shown, using a phase diagram loaded with LCOS, a portion of the control signal is transmitted to the detection port simultaneously with the transmission of the incident beam to the port. The incident beam carries a top-tuning signal. The detection port is used to detect the top-tuning signal carried in the input beam.
[0077] In one possible implementation, a phase grating is loaded onto the LCoS to control the spectral width of the signal output from the detection port, thereby suppressing dispersion and SRS effects and improving transmission distance. After the WSS receives the incident beam, it controls the spectral width of the optical signal diffracted by the LCoS to the output of the detection port within a set spectral width range using the phase grating. A first transmission distance supported by the set spectral range is greater than a second transmission distance, which is the maximum transmission distance supported by a spectral width greater than the maximum spectral width within the set spectral range. The spectral width of the incident beam is greater than the maximum spectral width.
[0078] During transmission, the transmission distance of the modulated signal is affected by chromatic dispersion, and the wider the spectral width, the greater the impact of dispersion. This application's embodiment combines the flexible spectral adjustment capability of LCOS to control the spectral width of the optical signal transmitted to the detection port, thereby suppressing dispersion and mitigating the effects of SRS, thus improving the transmission distance. For example, if W is the spectral width of the optical signal output from the detection port, then the spectral width range is set to [W1-a, W1+a]. 'a' can be an empirical value or determined experimentally. Within this set spectral width range, the signal attenuation is relatively small, and the transmission distance is relatively long. For example, if W1 = 50 GHz, 'a' can be 0.1 GHz, 1 GHz, 2 GHz, etc., and other values are also possible, with 'a' being greater than 0. The set spectral width range can be related to the required transmission distance of the system.
[0079] In some possible embodiments, the position of the spectral range of the optical signal output from the detection port within the spectral range of the incident beam can be in the middle segment, the front segment, or the rear segment of the spectral range of the incident beam. This application does not specifically limit this.
[0080] For example, the spectral range of the incident beam is [P1, P2].
[0081] In one possible implementation, the spectral range of the optical signal output from the detection port is in the earlier part of the spectral range of the incident beam, that is, the spectral range of the optical signal output from the detection port is [P1, P1+W], where W is the spectral width of the optical signal output from the detection port.
[0082] In another possible implementation, the spectral range of the optical signal output from the detection port is in the latter part of the spectral range of the incident beam, that is, the spectral range of the optical signal output from the detection port is [P2-W,P2].
[0083] In another possible implementation, the spectral range of the optical signal output from the detection port is in the middle segment of the spectral range of the incident beam, that is, the spectral range of the optical signal output from the detection port is [(P1+P2-W) / 2,(P1+P2+W) / 2].
[0084] For example, see Figure 9 As shown in (a), the incident beam has a spectral width of 100 GHz. The LCOS-loaded phase grating of the WSS filters out 50 GHz of the input beam and transmits it to the detection port to achieve dispersion suppression of the optical modulation signal. For example, if the spectral range of the incident beam is [50, 150], the spectral range of the output from the detection port can be [50, 100], [100, 150], or [75, 125], or other spectral ranges can be used. This application does not specifically limit this. See also Figure 9 As shown in (b), experiments have shown that transmitting a portion of the optical signal spectrum to the detection port, compared to transmitting the entire 100GHz signal to the detection port, allows for a longer maximum transmission distance and less attenuation.
[0085] In one possible example, the WSS may also include other structures, such as lenses, capable of repositioning the light signal diffracted by the LCoS, and then coupling the repositioned light signal to a specific output port. The WSS may also include a driving circuit. The driving circuit determines the driving voltage for each pixel in the LCoS based on the phase grating loaded on the LCoS. The driving circuit then outputs a corresponding driving voltage to each pixel on the LCoS.
[0086] In some implementation scenarios, see Figure 10 As shown, the detection port is used to connect to the optical sensor LS. The LS then detects the modulation signal from the optical signal output from the detection port. Figure 10 The diagram shows a detection device for the optical modulation signal. The detection device includes... Figure 7 The WSS and the top-mounted signal detection device are shown. The top-mounted signal detection device may also include a light sensor (LS). Figure 10 In this context, the optical signal in the main optical path refers to the optical signal output from the output port of the WSS.
[0087] Based on the first possible implementation, see Figure 11 The diagram shown is a schematic flowchart of a method for detecting optically tuned signals provided in an embodiment of this application. This detection method can be executed by a detection device. The detection method includes steps S1101-S1102.
[0088] S1101, a phase grating is loaded onto the LCoS in the WSS to modulate the incident beam of the WSS, so that the modulated incident beam diffracts to the detection port of the WSS and at least one of the multiple output ports; the phase grating controls the spectral width of the optical signal diffracted by the LCoS to the detection port to be within a set spectral width range, the first transmission distance supported by the set spectral range is greater than the second transmission distance, the second transmission distance is the transmission distance supported by the spectral width greater than the maximum spectral width within the set spectral range; the spectral width of the incident beam is greater than the maximum spectral width.
[0089] S1102 detects the tuning signal in the optical signal output from the detection port of the WSS via LS.
[0090] Furthermore, the applicant's research found that due to the SRS effect, the power unevenness of the signal leads to a lower signal-to-noise ratio for lower-power signals. Moreover, lower-power signals can cause crosstalk to higher-power signals at other wavelengths, see [link to relevant documentation]. Figure 12 As shown, in this case, if the top adjustment signal is detected, the detection time needs to be increased in order to achieve higher detection accuracy.
[0091] In another possible implementation, this application provides another detection scheme for optically calibrated signals. Utilizing the flexible beam splitting characteristics of an LCOS-based WSS, it ensures that the detection light diffracted at the LS detection port is relatively flat, i.e., meets the flatness requirement. Flattening effectively reduces detection time. The LCOS-based WSS dynamically adjusts the phase and direction of the reflected beam by changing the arrangement of liquid crystal molecules, achieving continuously adjustable wavelength splitting ratio. For example, adjusting the voltage can control the energy distribution ratio of different wavelengths among multiple output ports. The incident beam includes optical signals of N wavelengths, where N is an integer greater than 1. Thus, the phase grating controls the optical signal diffracted to the detection port by the LCoS to include N wavelengths, and the optical power of the N wavelengths in the output optical signal of the detection port meets the flatness requirement. For example, the flatness can be less than 1dB or 2dB, etc. Due to the SRS effect, signals with lower power have lower signal-to-noise ratios, requiring increased detection time to achieve detection accuracy. Flatness can be used to improve detection efficiency and reduce detection time. In some implementation scenarios, where the detection time requirement is short, the flatness value can be smaller.
[0092] In some possible embodiments, the optical power of each of the N wavelengths of the optical signal output from the detection port is less than or equal to the optical power of the first wavelength in the incident beam, where the first wavelength is the wavelength of the optical signal with the lowest optical power among the N wavelengths of the optical signal included in the incident beam. That is, after leveling, the optical power of each output wavelength is less than or equal to the minimum optical power among the N wavelengths of the optical signal included in the incident beam. See [link to relevant documentation]. Figure 13 As shown. Figure 13 In this system, the optical signal in the main optical path is the optical signal output from the output port of the WSS.
[0093] See Figure 14 The diagram shown illustrates another method for detecting optically tuned signals according to an embodiment of this application. This detection method is implemented using a detection device. The detection method includes steps S1401 and S1402.
[0094] S1401, A phase grating is loaded onto the LCoS in the WSS to modulate the incident beam of the WSS, so that the modulated incident beam is diffracted to the detection port of the WSS and at least one of the multiple output ports; the incident beam includes optical signals of N wavelengths, where N is a positive integer; the phase grating controls the optical signals diffracted by the LCoS to the detection port to include optical signals of N wavelengths, and the optical power of the N wavelength optical signals output by the detection port meets the flatness requirement.
[0095] S1402 detects the tuning signal in the optical signal output from the detection port of the WSS.
[0096] In a third possible implementation, a phase grating controls the spectral width of the optical signal diffracted by the LCoS to be within a set spectral width range at the output of the detection port. Furthermore, the optical power of the N wavelengths of the optical signal output from the detection port meets the flatness requirement.
[0097] See Figure 15 The diagram shown illustrates a method for detecting a light-modulated top signal according to an embodiment of this application. This detection method is performed by a detection device. The detection method includes steps S1501 and S1502.
[0098] S1501, A phase grating is loaded onto the LCoS in the WSS to modulate the incident beam of the WSS, so that the modulated incident beam is diffracted to the detection port of the WSS and at least one of the multiple output ports; the incident beam includes optical signals of N wavelengths, where N is a positive integer; the phase grating controls the optical signals diffracted by the LCoS to the detection port to include optical signals of N wavelengths, and the spectral width of the optical signals output by the detection port is within the set spectral width range and the optical power of the N wavelength optical signals output by the detection port meets the flatness requirement.
[0099] S1502 detects the tuning signal in the optical signal output from the detection port of the WSS.
[0100] The embodiments described above utilize the flexible beam splitting capability of the WSS to design a loaded grating phase map, controlling the power spectrum and magnitude of the beam split to the detection port for LS detection, thereby improving the detection performance of the LS signal. These embodiments can be applied to optical link node detection in C+L systems, enhancing the detection capability of link nodes, detecting link status, and improving link performance.
[0101] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the communication system described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.
[0102] One embodiment of this application provides a computer-readable medium for storing a computer program, the computer program including functions for executing... Figure 4 The instructions for the method steps in the corresponding method embodiment.
[0103] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, etc.) containing computer-usable program code.
[0104] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0105] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.
Claims
1. A wavelength selective switch (WSS), characterized in that, Includes input ports, multiple output ports, detection ports, and a silicon-based liquid crystal (LCoS). The input port is used to receive the incident beam, which carries a top-adjustment signal; The LCoS is used to load a phase grating to modulate the incident beam, so that the modulated incident beam diffracts onto the detection port and at least one of the plurality of output ports. The detection port is used to detect the top-tuning signal; the phase grating controls the spectral width of the light signal diffracted by the LCoS to the detection port to be within a set spectral width range, the first transmission distance supported by the set spectral range is greater than the second transmission distance, the second transmission distance is the maximum transmission distance supported by the spectral width greater than the maximum spectral width within the set spectral range; the spectral width of the incident beam is greater than the maximum spectral width.
2. The WSS as described in claim 1, characterized in that, The spectral range of the incident beam is [P1, P2]; The spectral range of the optical signal output from the detection port is [P1, P1+W], where W is the spectral width of the optical signal output from the detection port; or, The spectral range of the optical signal output from the detection port is [P2-W, P2], where W is the spectral width of the optical signal output from the detection port; or, The spectral range of the optical signal output from the detection port is [(P1+P2-W) / 2, (P1+P2+W) / 2], where W is the spectral width of the optical signal output from the detection port.
3. The WSS as described in claim 1 or 2, characterized in that, The incident beam includes optical signals of N wavelengths, where N is an integer greater than 1; the phase grating controls the optical signals diffracted by the LCoS to the detection port, which include the optical signals of the N wavelengths.
4. The WSS as described in claim 3, characterized in that, The optical power of the N wavelengths of the optical signal output from the detection port meets the flatness requirement.
5. The WSS as described in claim 4, characterized in that, The optical power of each of the N wavelengths of the optical signal output from the detection port is less than or equal to the optical power of the first wavelength in the incident beam. The first wavelength is the wavelength of the optical signal with the lowest optical power among the N wavelengths of the optical signal included in the incident beam.
6. A wavelength selective switch (WSS), characterized in that, Includes input ports, multiple output ports, detection ports, and a silicon-based liquid crystal (LCoS). The input port is used to receive an incident light beam, which carries a top-tuning signal; the incident light beam includes optical signals of N wavelengths, where N is a positive integer. The LCoS is used to load a phase grating to modulate the incident beam, so that the modulated incident beam diffracts onto the detection port and at least one of the plurality of output ports. The detection port is used to detect the optical top-tuning signal; the phase grating controls the optical signal diffracted by the LCoS to the detection port to include the optical signals of the N wavelengths, and the optical power of the optical signals of the N wavelengths output by the detection port meets the flatness requirement.
7. The WSS as described in claim 6, characterized in that, The optical power of each of the N wavelengths of the optical signal output from the detection port is less than or equal to the optical power of the first wavelength in the incident beam. The first wavelength is the wavelength of the optical signal with the lowest optical power among the N wavelengths of the optical signal included in the incident beam.
8. A device for detecting optically tuned signals, characterized in that, Includes the WSS and the top-mounted signal detection device as described in any one of claims 1-7, wherein the top-mounted signal detection device is connected to the detection port of the WSS; The top-mounting signal detection device is used to detect the top-mounting signal from the optical signal output from the detection port.
9. A method for detecting optically tuned signals, characterized in that, include: A phase grating is loaded onto the silicon-based liquid crystal (LCoS) in a wavelength selective switch (WSS) to modulate the incident light beam of the WSS, causing the modulated incident light beam to diffract onto the detection port of the WSS and at least one of the multiple output ports; the incident light beam carries a modulation signal; the phase grating controls the spectral width of the light signal diffracted by the LCoS to the detection port to be within a set spectral width range, wherein the set spectral range supports a first transmission distance greater than a second transmission distance, and the second transmission distance is a transmission distance supported by a spectral width greater than the maximum spectral width within the set spectral range; the spectral width of the incident light beam is greater than the maximum spectral width; The tuning signal is detected in the optical signal output from the detection port.
10. The method as described in claim 9, characterized in that, The spectral range of the incident beam is [P1, P2]; The spectral range of the optical signal output from the detection port is [P1, P1+W], where W is the spectral width of the optical signal output from the detection port; or, The spectral range of the optical signal output from the detection port is [P2-W, P2], where W is the spectral width of the optical signal output from the detection port; or, The spectral range of the optical signal output from the detection port is [(P1+P2-W) / 2, (P1+P2+W) / 2], where W is the spectral width of the optical signal output from the detection port.
11. The method as described in claim 9 or 10, characterized in that, The incident beam includes optical signals of N wavelengths, where N is an integer greater than 1; the phase grating controls the optical signals output by the LCoS from the detection port, which include the optical signals of the N wavelengths.
12. The method as described in claim 11, characterized in that, The optical power of the N wavelengths of the optical signal output from the detection port meets the flatness requirement.
13. The method as described in claim 12, characterized in that, The optical power of each of the N wavelengths of the optical signal output from the detection port is less than or equal to the optical power of the first wavelength in the incident beam. The first wavelength is the wavelength of the optical signal with the lowest optical power among the N wavelengths of the optical signal included in the incident beam.
14. A method for detecting optically tuned signals, characterized in that, include: A phase grating is loaded onto the silicon-based liquid crystal (LCoS) in a wavelength selective switch (WSS) to modulate the incident beam of the WSS, such that the modulated incident beam diffracts to the detection port of the WSS and at least one of the multiple output ports; the incident beam carries a top-tuning signal; the incident beam includes optical signals of N wavelengths, where N is a positive integer; the phase grating controls the optical signals diffracted by the LCoS to the detection port to include the optical signals of the N wavelengths, and the optical power of the optical signals of the N wavelengths output by the detection port meets the flatness requirement; The tuning signal is detected in the optical signal output from the detection port.
15. The method as described in claim 14, characterized in that, The optical power of each of the N wavelengths of the optical signal output from the detection port is less than or equal to the optical power of the first wavelength in the incident beam. The first wavelength is the wavelength of the optical signal with the lowest optical power among the N wavelengths of the optical signal included in the incident beam.