Optical switching device, method and related equipment

Abstract

The present application discloses an optical switching device, method, and related equipment. The device includes a first input port, a second input port, a first polarization conversion component, a second polarization conversion component, a polarization separation component, a redirection component, and an output port. A first light beam is input from the first input port, and a second light beam is input from the second input port. The first light beam can be signal light, and the second light beam can be dummy light. The redirection component can convert the polarization states of the signal light and the dummy light so that the dummy light is transmitted to the output port. In this way, the uploading of the dummy light is achieved. The device can use silicon-based liquid crystal that supports switching between two liquid crystal states, reducing the response time and meeting the requirement for fast uploading of the dummy light. In addition, the background losses such as silicon-based liquid crystal reflection loss and liquid crystal absorption loss in the device are relatively low, resulting in low loss of signal light or dummy light.

Description

Technical Field

[0001] The present application relates to the field of optical communication technology, and in particular to an optical switching device, method, and related equipment. Background Art

[0002] With the rapid development of optical network services and the increase in switching capacity, the signal wavelength ranges that reconfigurable optical add-drop module (ROADM) sites need to process are also expanding. In optical fiber transmission systems, due to the nonlinear stimulated Raman scattering (SRS) effect, the energy of short-wavelength signals is transferred to long-wavelength signals, degrading the optical signal-to-noise ratio (OSNR) of short-wavelength signals and necessitating signal power balancing. However, the increasing number of channels at ROADM sites complicates the SRS effect, making signal power balancing even more challenging.

[0003] Currently, wavelength selective switches (WSS) can be used at ROADM sites to upload dummy light to fill idle channels to reduce the impact of the SRS effect, so that the link is always in a full-wave state, the SRS effect is stable, and it is easy to balance the signal power. When certain wavelength signals are dropped, the WSS at the ROADM site needs to be able to quickly upload dummy light to fill the channel of the dropped signal, thereby reducing the impact of the SRS effect. ROADM sites mainly use WSS based on silicon-based liquid crystal (LCOS) chips. Among them, LCOS that supports multiple phase values usually has a longer liquid crystal response time. The WSS using this LCOS chip does not meet the demand for fast uploading of dummy light. In addition, the LCOS that supports two phase values has a shorter liquid crystal response time, but it will cause greater insertion loss to the signal light or dummy light. Summary of the Invention

[0004] The present application provides an optical switching device, method and related equipment, which can quickly upload dummy light and reduce the insertion loss of signal light or dummy light.

[0005] In the first aspect, the present application provides an optical switching device, comprising a first input port, a second input port, a first polarization conversion component, a second polarization conversion component, a polarization separation component, a redirection component and an output port, wherein the first input port is used to input a first light beam; the second input port is used to input a second light beam; the first polarization conversion component is used to convert the polarization state of the input first light beam into a first polarization state; the second polarization conversion component is used to convert the polarization state of the input second light beam into a second polarization state, and the polarization directions of the second polarization state and the first polarization state are orthogonal to each other; the polarization separation component is used to pass through the first light beam of the first polarization state and reflect the second light beam of the second polarization state; the redirection component is used to reflect the first light beam of the first polarization state and the second light beam of the second polarization state; or is used to convert the polarization state of the first light beam of the first polarization state into the second polarization state and reflect the first light beam of the second polarization state, and convert the polarization state of the second light beam of the second polarization state into the first polarization state and reflect the second light beam of the first polarization state; wherein the light beam of the first polarization state reflected by the redirection component passes through the polarization separation component, and is polarization-converted by the first polarization conversion component and output to the output port.

[0006] In the above device, the first light beam can be signal light, and the second light beam can be dummy light. The redirection component converts the polarization state of the signal light in the first polarization state to the second polarization state, and converts the polarization state of the dummy light in the second polarization state to the first polarization state. The dummy light in the first polarization state reflected by the redirection component passes through the polarization separation component and is output to the output port. Alternatively, the first light beam can be dummy light, and the second light beam can be signal light. The redirection component does not convert the polarization states of the signal light and the dummy light. The dummy light in the first polarization state reflected by the redirection component passes through the polarization separation component and is output to the output port. This enables the uploading of dummy light at a ROADM site, and the redirection component can either convert or not convert the polarization state of the light beam. The above device can utilize LCOS that supports switching between two liquid crystal states, reducing response time and ensuring fast uploading of dummy light. Furthermore, the background losses in the above device, such as LCOS reflection loss and liquid crystal absorption loss, minimize losses to either signal light or dummy light.

[0007] In combination with the first aspect, in a possible implementation of the first aspect, the device further includes a dispersion component, which is located between the polarization separation component and the redirection component; the dispersion component is used to separate the first light beam in the first polarization state and the second light beam in the second polarization state into multiple sub-wavelength light beams in a dispersion plane, the multiple sub-wavelength light beams of the first light beam are incident on different positions of the redirection component, and the multiple sub-wavelength light beams of the second light beam are incident on different positions of the redirection component, the sub-wavelength light beams of the first light beam and the sub-wavelength light beams of the second light beam with the same wavelength are incident on the redirection component at the same position, and the dispersion plane is the plane where the dispersion component disperses the light beams into different propagation directions.

[0008] In combination with the first aspect, in a possible implementation of the first aspect, the device further includes a first lens, a second lens, and a third lens, the second lens is located between the first lens and the third lens, the dispersion component is located at the back focus of the first lens and the front focus of the third lens, and the redirection component is located at the back focus of the third lens.

[0009] In combination with the first aspect, in a possible implementation of the first aspect, the device also includes a reflector, which is located behind the second polarization conversion component; the reflector is used to reflect the second light beam in the second polarization state so that the second light beam in the second polarization state is incident on the polarization separation component.

[0010] In combination with the first aspect, in a possible embodiment of the first aspect, the redirection component is specifically used to: reflect all sub-wavelength beams in the first light beam in the first polarization state and all sub-wavelength beams in the second light beam in the second polarization state; or convert the polarization state of all or part of the sub-wavelength beams in the first light beam in the first polarization state into the second polarization state and reflect the sub-wavelength beam after the polarization state is converted, and convert the polarization state of all or part of the sub-wavelength beams in the second light beam in the second polarization state into the first polarization state and reflect the sub-wavelength beam after the polarization state is converted; wherein the sub-wavelength beam of the first polarization state reflected by the redirection component passes through the polarization separation component, and is output to the output port after polarization conversion by the first polarization conversion component.

[0011] In combination with the first aspect, in a possible implementation manner of the first aspect, the redirection component includes a polarization modulator, and when the liquid crystal molecules in the polarization modulator are in a preset arrangement state, the polarization modulator converts the polarization state of the received light beam.

[0012] In combination with the first aspect, in a possible embodiment of the first aspect, the redirection component includes a 1 / 2 wave plate and a phase modulator; the 1 / 2 wave plate is used to adjust the polarization direction of the first light beam in the first polarization state and the second light beam in the second polarization state incident on the phase modulator, so that the angle between the polarization direction of the first light beam incident on the phase modulator and the fast axis of the phase modulator is a first angle, and the angle between the polarization direction of the second light beam incident on the phase modulator and the fast axis of the phase modulator is a second angle, and the first angle and the second angle are 45 degrees or the difference from 45 degrees is less than a preset threshold; the phase modulator is used to generate a phase change on the first light beam and the second light beam after the polarization direction is adjusted by the 1 / 2 wave plate; when a phase change of an odd multiple of π is generated on the first light beam and the second light beam, the polarization state of the first light beam and the second light beam is converted.

[0013] In combination with the first aspect, in a possible implementation manner of the first aspect, it is characterized in that, when a phase change of 0 or an even multiple of π is generated for the first light beam and the second light beam, the angle between the polarization direction of the first light beam exiting the phase modulator and the fast axis of the phase modulator is the first angle, and the angle between the polarization direction of the second light beam exiting the phase modulator and the fast axis of the phase modulator is the second angle; when a phase change of an odd multiple of π is generated for the first light beam and the second light beam, the angle between the polarization direction of the first light beam exiting the phase modulator and the fast axis of the phase modulator is a third angle, and the angle between the polarization direction of the second light beam exiting the phase modulator and the fast axis of the phase modulator is a fourth angle; the third angle is symmetrical with the first angle about the fast axis of the phase modulator, and the fourth angle is symmetrical with the second angle about the fast axis of the phase modulator.

[0014] In combination with the first aspect, in a possible implementation manner of the first aspect, the first light beam includes a signal light beam, the second light beam includes a dummy light beam, and the positions at which the first light beam and the second light beam are incident on the redirection component are consistent.

[0015] In combination with the first aspect, in a possible embodiment of the first aspect, the angle at which the first light beam and the second light beam are incident on the redirection component in the port plane or port direction is not 0, the positions of the first input port and the output port in the port direction are different, and the angle at which the first light beam and the second light beam are incident on the redirection component in the port plane or port direction is the angle between the first light beam and the second light beam and the normal of the redirection component.

[0016] In combination with the first aspect, in a possible embodiment of the first aspect, the angle at which the first light beam and the second light beam are incident on the redirection component in the port plane or port direction is 0, and the device also includes a circulator and an isolator, the circulator is located between the first input port and the first polarization conversion component, and the isolator is located between the second input port and the second polarization conversion component; the circulator is used to transmit the light beam input from the first input port to the first polarization conversion component, and to transmit the light beam output from the first polarization conversion component to the output port; the isolator is used to transmit the light beam input from the second input port to the second polarization conversion component, and to isolate the light beam output from the second polarization conversion component.

[0017] In combination with the first aspect, in a possible implementation of the first aspect, the redirection component includes liquid crystal on silicon (LCOS) based on ferroelectric liquid crystal material, bistable liquid crystal material, or nematic liquid crystal material.

[0018] In a second aspect, the present application provides a reconfigurable optical add-drop multiplexing device ROADM, wherein the ROADM includes a first wavelength selection switch WSS and a second WSS, wherein the first WSS is used to exchange signal light, and the second WSS includes the device in the first aspect or any possible embodiment of the first aspect, and is used to replace at least part of the wavelength signal of the signal light with a false optical signal.

[0019] In the aforementioned device, the second WSS is used to replace at least some wavelengths of the signal light with dummy light signals. This enables the uploading of dummy light at the ROADM site. Furthermore, the second WSS can utilize LCOS, which supports switching between two liquid crystal states, reducing response time and enabling rapid uploading of the dummy light. Furthermore, the background losses in the second WSS, such as LCOS reflection loss and liquid crystal absorption loss, contribute minimal losses to the signal light or dummy light.

[0020] In combination with the second aspect, in a possible implementation manner of the second aspect, the device also includes a first optical amplifier, a second optical amplifier and a third WSS, the first optical amplifier, the third WSS, the first WSS and the second optical amplifier are arranged in sequence from front to back, and the second WSS is located between the first WSS and the second optical amplifier, or after the second optical amplifier, or between the first-stage optical amplification unit and the second-stage optical amplification unit included in the second optical amplifier, or between the first optical amplifier and the third WSS, or before the first optical amplifier.

[0021] In a third aspect, the present application provides an optical switching method, which is applied to an optical switching device, the device comprising a first input port, a second input port, a first polarization conversion component, a second polarization conversion component, a polarization separation component, a redirection component and an output port, and the method comprising: the first input port inputs a first light beam; the second input port inputs a second light beam; the first polarization conversion component converts the polarization state of the input first light beam into a first polarization state; the second polarization conversion component converts the polarization state of the input second light beam into a second polarization state, and the polarization directions of the second polarization state and the first polarization state are orthogonal to each other; the polarization separation component passes through the first light beam of the first polarization state and reflects the second light beam of the second polarization state; the redirection component reflects the first light beam of the first polarization state and the second light beam of the second polarization state; or converts the polarization state of the first light beam of the first polarization state into the second polarization state and reflects the first light beam of the second polarization state, and converts the polarization state of the second light beam of the second polarization state into the first polarization state and reflects the second light beam of the first polarization state; wherein the light beam of the first polarization state reflected by the redirection component passes through the polarization separation component, and is polarization-converted by the first polarization conversion component and output to the output port.

[0022] In the above method, the first light beam can be signal light, and the second light beam can be dummy light. The redirection component converts the polarization state of the signal light in the first polarization state to the second polarization state, and converts the polarization state of the dummy light in the second polarization state to the first polarization state. The dummy light in the first polarization state reflected by the redirection component passes through the polarization separation component and is output to the output port. Alternatively, the first light beam can be dummy light, and the second light beam can be signal light. The redirection component does not convert the polarization states of the signal light and the dummy light. The dummy light in the first polarization state reflected by the redirection component passes through the polarization separation component and is output to the output port. This enables the uploading of dummy light at a ROADM site. The redirection component can either convert or not convert the polarization state of the light beam. The optical switching device can utilize LCOS, which supports switching between two liquid crystal states. This reduces response time and enables fast uploading of dummy light. Furthermore, the background losses in the optical switching device, such as LCOS reflection loss and liquid crystal absorption loss, minimize losses to signal light or dummy light.

[0023] In combination with the third aspect, in a possible implementation of the third aspect, the device further includes a dispersion component, wherein the dispersion component is located between the polarization separation component and the redirection component, and the method further includes: the dispersion component separates the first light beam of the first polarization state and the second light beam of the second polarization state into multiple sub-wavelength light beams in a dispersion plane, the multiple sub-wavelength light beams of the first light beam are incident on different positions of the redirection component, and the multiple sub-wavelength light beams of the second light beam are incident on different positions of the redirection component, the sub-wavelength light beams of the first light beam and the sub-wavelength light beams of the second light beam with the same wavelength are incident on the redirection component at the same position, and the dispersion plane is a plane where the dispersion component disperses the light beams into different propagation directions.

[0024] In combination with the third aspect, in a possible implementation of the third aspect, the device further includes a first lens, a second lens, and a third lens, the second lens is located between the first lens and the third lens, the dispersion component is located at the back focus of the first lens and the front focus of the third lens, and the redirection component is located at the back focus of the third lens.

[0025] In combination with the third aspect, in a possible implementation of the third aspect, the device also includes a reflector, which is located behind the second polarization conversion component, and the method also includes: the reflector reflects the second light beam in the second polarization state so that the second light beam in the second polarization state is incident on the polarization separation component.

[0026] In combination with the third aspect, in a possible embodiment of the third aspect, the redirection component reflects the first light beam in the first polarization state and the second light beam in the second polarization state; or converts the polarization state of the first light beam in the first polarization state into the second polarization state and reflects the first light beam in the second polarization state, and converts the polarization state of the second light beam in the second polarization state into the first polarization state and reflects the second light beam in the first polarization state, including: the redirection component reflects all sub-wavelength light beams in the first light beam in the first polarization state and all sub-wavelength light beams in the second light beam in the second polarization state; or converts the polarization state of all or part of the sub-wavelength light beams in the first light beam in the first polarization state into the second polarization state and reflects the sub-wavelength light beam after the polarization state is converted, and converts the polarization state of all or part of the sub-wavelength light beams in the second light beam in the second polarization state into the first polarization state and reflects the sub-wavelength light beam after the polarization state is converted; wherein the sub-wavelength light beam in the first polarization state reflected by the redirection component passes through the polarization separation component, and is output to the output port after being polarization-converted by the first polarization conversion component.

[0027] In combination with the third aspect, in a possible implementation of the third aspect, the redirection component includes a polarization modulator, and the method further includes: when the liquid crystal molecules in the polarization modulator are in a preset arrangement state, the polarization modulator converts the polarization state of the received light beam.

[0028] In combination with the third aspect, in a possible embodiment of the third aspect, the redirection component includes a 1 / 2 wave plate and a phase modulator, and the method further includes: the 1 / 2 wave plate adjusts the polarization direction of the first light beam in the first polarization state and the second light beam in the second polarization state incident on the phase modulator, so that the angle between the polarization direction of the first light beam incident on the phase modulator and the fast axis of the phase modulator is a first angle, and the angle between the polarization direction of the second light beam incident on the phase modulator and the fast axis of the phase modulator is a second angle, and the first angle and the second angle are 45 degrees or the difference from 45 degrees is less than a preset threshold; the phase modulator generates a phase change on the first light beam and the second light beam after the polarization direction is adjusted by the 1 / 2 wave plate; when a phase change of an odd multiple of π is generated on the first light beam and the second light beam, the polarization state of the first light beam and the second light beam is converted.

[0029] In combination with the third aspect, in a possible implementation of the third aspect, when a phase change of 0 or an even multiple of π is generated for the first light beam and the second light beam, the angle between the polarization direction of the first light beam exiting the phase modulator and the fast axis of the phase modulator is the first angle, and the angle between the polarization direction of the second light beam exiting the phase modulator and the fast axis of the phase modulator is the second angle; when a phase change of an odd multiple of π is generated for the first light beam and the second light beam, the angle between the polarization direction of the first light beam exiting the phase modulator and the fast axis of the phase modulator is a third angle, and the angle between the polarization direction of the second light beam exiting the phase modulator and the fast axis of the phase modulator is a fourth angle; the third angle is symmetrical with the first angle about the fast axis of the phase modulator, and the fourth angle is symmetrical with the second angle about the fast axis of the phase modulator.

[0030] In combination with the third aspect, in a possible implementation manner of the third aspect, the first light beam includes a signal light beam, the second light beam includes a dummy light beam, and the positions at which the first light beam and the second light beam are incident on the redirection component are consistent.

[0031] In combination with the third aspect, in a possible embodiment of the third aspect, the angle at which the first light beam and the second light beam are incident on the redirection component in the port plane or port direction is not 0, the positions of the first input port and the output port in the port direction are different, and the angle at which the first light beam and the second light beam are incident on the redirection component in the port plane or port direction is the angle between the first light beam and the second light beam and the normal of the redirection component.

[0032] In combination with the third aspect, in a possible embodiment of the third aspect, the angle at which the first light beam and the second light beam are incident on the redirection component in the port plane or port direction is 0, and the device also includes a circulator and an isolator, the circulator is located between the first input port and the first polarization conversion component, and the isolator is located between the second input port and the second polarization conversion component, and the method also includes: the circulator transmits the light beam input from the first input port to the first polarization conversion component, and transmits the light beam output from the first polarization conversion component to the output port; the isolator transmits the light beam input from the second input port to the second polarization conversion component, and isolates the light beam output from the second polarization conversion component.

[0033] In combination with the third aspect, in a possible implementation of the third aspect, the redirection component includes liquid crystal on silicon (LCOS) based on ferroelectric liquid crystal material, bistable liquid crystal material, or nematic liquid crystal material. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the influence of SRS effect on optical signals;

[0035] Figure 2 Schematic diagram of using WSS to download false light for ROADM sites;

[0036] Figure 3 is a schematic diagram of the phase value of the blazed grating;

[0037] Figure 4 is a schematic diagram of the phase value of the binary grating;

[0038] Figure 5 Schematic diagram of ROADM using binary grating LCOS for fast uploading of false light;

[0039] Figure 6 A schematic diagram of an optical switching device provided in an embodiment of the present application;

[0040] Figure 7 A schematic diagram of an optical switching device in the dispersion direction provided in an embodiment of the present application;

[0041] Figure 8 for Figure 7 Schematic diagram of the optical switching device in the port direction;

[0042] Figure 9 A schematic diagram of light spot distribution on a redirection component in an optical switching device provided in an embodiment of the present application;

[0043] Figure 10 is a schematic diagram of liquid crystal molecules in a polarization modulator in a first arrangement state;

[0044] Figure 11 is a schematic diagram of the liquid crystal molecules in the polarization modulator being in a second arrangement state;

[0045] Figure 12 A schematic diagram of another optical switching device in the dispersion direction provided in an embodiment of the present application;

[0046] Figure 13 for Figure 12 Schematic diagram of the optical switching device in the port direction;

[0047] Figure 14 for Figure 12 Schematic diagram of the polarization direction of the light beam incident on the phase modulator;

[0048] Figure 15 for Figure 12 Schematic diagram of the polarization direction of the mid-beam exiting the phase modulator;

[0049] Figure 16 A schematic diagram of another optical switching device in the dispersion direction provided in an embodiment of the present application;

[0050] Figure 17 for Figure 16 Schematic diagram of the optical switching device in the port direction;

[0051] Figure 18 A schematic diagram of another optical switching device in the dispersion direction provided in an embodiment of the present application;

[0052] Figure 19 for Figure 18 Schematic diagram of the optical switching device in the port direction;

[0053] Figure 20 A schematic diagram of a ROADM provided in an embodiment of the present application;

[0054] Figure 21 A schematic diagram of another ROADM provided in an embodiment of the present application;

[0055] Figure 22 A schematic diagram of another ROADM provided in an embodiment of the present application;

[0056] Figure 23 A schematic diagram of another ROADM provided in an embodiment of the present application;

[0057] Figure 24 A schematic diagram of another ROADM provided in an embodiment of the present application;

[0058] Figure 25 A schematic diagram of another ROADM provided in an embodiment of the present application;

[0059] Figure 26 A schematic diagram of another ROADM provided in an embodiment of the present application;

[0060] Figure 27 A schematic diagram of another ROADM provided in an embodiment of the present application;

[0061] Figure 28 A schematic diagram of an optical switching method provided in an embodiment of the present application;

[0062] Figure 29 A schematic diagram of a light energy attenuation method provided in an embodiment of the present application;

[0063] Figure 30 A schematic diagram of attenuating the energy of new false light provided in an embodiment of the present application. DETAILED DESCRIPTION

[0064] The technical solution in this application will be described below with reference to the accompanying drawings.

[0065] Below, some terms used in the embodiments of the present application are explained to facilitate understanding by those skilled in the art.

[0066] The "at least one" involved in the embodiments of the present application refers to one or more, and "more" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0067] Furthermore, unless otherwise indicated, ordinal numbers such as "first" and "second" in the embodiments of this application are used to distinguish multiple objects and are not used to define the order, timing, priority, or importance of multiple objects. For example, the first information and the second information are only used to distinguish different information and do not indicate differences in content, priority, transmission order, or importance between the two information.

[0068] To facilitate understanding of this application, the concepts involved in this application are first explained:

[0069] With the rapid development of optical network services and the increase in switching capacity, the range of signal wavelengths that reconfigurable optical add-drop module (ROADM) sites need to process is also increasing. Wavelength selective switches (WSS), based on optical switch arrays such as liquid crystal (LC) array chips, liquid crystal on silicon (LCOS) chips, or micro electromechanical systems (MEMS) chips, are important components of ROADM sites. In optical fiber transmission systems, due to the influence of nonlinear stimulated Raman scattering (SRS), the energy of short-wavelength signals is transferred to long-wavelength signals, degrading the optical signal-to-noise ratio (OSNR) of short-wavelength signals and necessitating signal power balancing.

[0070] See also Figure 1 , Figure 1 Schematic diagram of the impact of SRS effect on optical signals. Figure 1 As shown, the energy of short-wavelength signals is transferred to long-wavelength signals. The wider the signal band, the more severe the SRS effect. Furthermore, uploading or downloading signal waves at ROADM sites causes the number of channels to fluctuate. This change in the number of channels complicates the SRS effect, requiring monitoring and dynamic power balancing, making signal power balancing even more challenging.

[0071] Currently, one method for mitigating SRS damage is to use WSS at ROADM sites to upload dummy light to fill idle channels. This ensures the link is always fully loaded, stabilizes the SRS effect, simplifies SRS monitoring, and facilitates signal power balancing. When certain wavelengths drop out (for example, due to laser source damage or erbium-doped optical fiber amplifier (EDFA) failure), the ROADM WSS needs to be able to quickly upload dummy light (typically within 10ms) to fill the dropped signal channel, minimizing signal power fluctuations and damage caused by EDFA transients or fiber SRS.

[0072] See also Figure 2 , Figure 2 The following is a schematic diagram of using WSS to download false light at ROADM sites. Figure 2 As shown, optical fibers transmit light beams of different wavelengths: λ_1, λ_2, λ_3, λ_4, λ_5, and λ_6. Wavelengths λ_1, λ_3, λ_5, and λ_6 are signal light, while wavelengths λ_2 and λ_4 are dummy light. Signal light carries service information, while dummy light does not. After passing through an optical amplifier, the light beam is transmitted to the first WSS. The first WSS drops or blocks the dummy light at wavelengths λ_2 and λ_4. After passing through the first WSS, the light beam is transmitted to the first add-drop wavelength selective switch (ADWSS). The first ADWSS drops signal light at wavelength λ_6. After passing through the first WSS and the first ADWSS, the light beam contains wavelengths λ_1, λ_3, and λ_5, all of which are signal light. When the light beam reaches the second WSS, the second WSS carries dummy light with wavelength λ_6, while the second ADWSS carries signal light with wavelengths λ_2 and λ_4. After passing through the second WSS, the light beam is transmitted to the optical amplifier. At this time, the wavelengths of the light beam transmitted on the optical fiber include λ_1, λ_2, λ_3, λ_4, λ_5, and λ_6. The light with wavelengths of λ_1, λ_2, λ_3, λ_4, and λ_5 is signal light, and the light with wavelength λ_6 is dummy light.

[0073] ROADM sites mainly use WSS based on LCOS chips. LCOS chips produce a diffraction effect on the light beam by loading a periodic phase grating, thereby deflecting the light beam at different angles.

[0074] In one embodiment, the LCOS chip is loaded with a blazed grating having multiple phase values, see Figure 3 , Figure 3 is a schematic diagram of the phase value of the blazed grating. Figure 3As shown in Figure 1, within period T, the phase values of the blazed grating include 0, 1 / 2π, π, and 3 / 2π. LCOS chips loaded with blazed gratings can support the switching of multi-angle and multi-port WSSs, but require complex circuitry to drive image loading, which results in a relatively large electrical delay (typically greater than 50ms). Furthermore, these LCOS chips typically use nematic liquid crystal materials, which have a relatively long response time (typically greater than 50ms). Therefore, WSSs using these LCOS chips cannot meet the requirements for fast false light uploading.

[0075] In another embodiment, the LCOS chip is loaded with a binary grating having two phase values, see Figure 4 , Figure 4 is a schematic diagram of the phase value of the binary grating. Figure 4 As shown, within period T, the phase values of the binary grating include 0 and π. The LCOS chip loaded with the binary grating switches between two states, requiring only a simple circuit to drive the loaded image, which can significantly reduce electrical delay (typically less than 5ms). Furthermore, the LCOS chip can use smectic liquid crystal materials to reduce the liquid crystal response time, such as ferroelectric liquid crystal materials (the liquid crystal response time is typically less than 1ms). LCOS chips using ferroelectric liquid crystal materials support switching between two states or two deflection angles. Although the LCOS chip loaded with the binary grating produces lower delay, the diffraction efficiency of the binary grating is low (typically less than 41%). ROADMs that use binary grating LCOS to quickly upload dummy light will incur significant insertion loss to the signal light or dummy light.

[0076] See also Figure 5 , Figure 5 Schematic diagram of ROADM using binary grating LCOS to quickly upload false light. Figure 5As shown in the figure, optical fibers transmit light beams of different wavelengths: λ_1, λ_2, λ_3, λ_4, λ_5, and λ_6. Wavelengths λ_1, λ_3, λ_5, and λ_6 are signal light, while wavelengths λ_2 and λ_4 are dummy light. After passing through an optical amplifier, the light beam is transmitted to the first WSS, which either drops or blocks dummy light at wavelengths λ_2 and λ_4. After passing through the first WSS, the light beam is transmitted to the first ADWSS, which drops signal light at wavelength λ_6. After passing through the first WSS and the first ADWSS, the light beam contains wavelengths λ_1, λ_3, and λ_5, all of which are signal light. When the light beam is transmitted to the second WSS and the second ADWSS, the second ADWSS carries signal light at wavelengths λ_2 and λ_4. After passing through the second WSS and the second ADWSS, the light beam is transmitted to an ultrafast 2x1 WSS, where the ultrafast 2x1 WSS carries dummy light at wavelength λ_6. After passing through the ultrafast 2x1 WSS, the light beam is transmitted to the optical amplifier. The wavelengths of the light beam transmitted on the optical fiber include λ_1, λ_2, λ_3, λ_4, λ_5, and λ_6. The wavelengths λ_1, λ_2, λ_3, λ_4, and λ_5 are signal light, while the wavelength λ_6 is dummy light. The line-side WSS switches signal light between different dimensions and directions. The client-side ADWSS is used for signal upload and download. The ultrafast 2x1 WSS cascaded with the WSS is used for rapid upload of dummy light. The ultrafast 2x1 WSS uses binary grating LCOS, which results in significant insertion loss for both signal and dummy light.

[0077] The background technology of this application is introduced above, and the technical features of the embodiments of this application are introduced below.

[0078] See also Figure 6 , Figure 6 This is a schematic diagram of an optical switching device provided in an embodiment of the present application. Figure 6 As shown, the optical switching device 600 includes a first input port 601 , a second input port 602 , a first polarization conversion component 603 , a second polarization conversion component 604 , a polarization separation component 605 , a redirection component 606 and an output port 607 . Figure 6 This is a schematic diagram of the light beam transmission direction in the optical switching device 600, and does not limit the positions of various ports and components.

[0079] exist Figure 6In the optical switching device 600 shown, a first input port 601 is used to input a first light beam. A second input port 602 is used to input a second light beam. A first polarization conversion component 603 is used to convert the polarization state of the input first light beam into a first polarization state. A second polarization conversion component 604 is used to convert the polarization state of the input second light beam into a second polarization state, wherein the polarization directions of the second polarization state and the first polarization state are orthogonal to each other. A polarization separation component 605 is used to pass the first light beam of the first polarization state and reflect the second light beam of the second polarization state. A redirection component 606 is used to reflect the first light beam of the first polarization state and the second light beam of the second polarization state; or to convert the polarization state of the first light beam of the first polarization state into the second polarization state and reflect the first light beam of the second polarization state, and convert the polarization state of the second light beam of the second polarization state into the first polarization state and reflect the second light beam of the first polarization state; wherein the light beam of the first polarization state reflected by the redirection component passes through the polarization separation component and is polarization-converted by the first polarization conversion component and output to the output port 607.

[0080] Optionally, the first light beam includes a signal light beam, the second light beam includes a dummy light beam, and the first light beam and the second light beam are incident on the redirection component 606 at the same position, wherein the consistent position includes the same position or the distance between the positions is less than a preset distance threshold.

[0081] In the above device, when the first light beam is signal light and the second light beam is dummy light, the redirection component can convert the polarization state of the signal light in the first polarization state into the second polarization state, and convert the polarization state of the dummy light in the second polarization state into the first polarization state. In this case, the dummy light in the first polarization state reflected by the redirection component passes through the polarization separation component and is output to the output port. The redirection component can also not convert the polarization states of the signal light and the dummy light. In this case, the signal light in the first polarization state reflected by the redirection component passes through the polarization separation component and is output to the output port. In addition, when the first light beam is dummy light and the second light beam is signal light, the redirection component can not convert the polarization states of the signal light and the dummy light. In this case, the dummy light in the first polarization state reflected by the redirection component passes through the polarization separation component and is output to the output port. The redirection component can also convert the polarization state of the dummy light in the first polarization state into the second polarization state, and convert the polarization state of the signal light in the second polarization state into the first polarization state. In this case, the signal light in the first polarization state reflected by the redirection component passes through the polarization separation component and is output to the output port. This enables the upload of dummy light at ROADM sites, and the redirection component can either convert or not convert the polarization state of the beam. The device utilizes LCOS, which supports switching between two liquid crystal states, reducing response time and enabling rapid upload of dummy light. Furthermore, the device minimizes background losses, such as LCOS reflection loss and liquid crystal absorption loss, resulting in minimal loss of signal or dummy light.

[0082] See also Figure 7 , Figure 7 This is a schematic diagram of an optical switching device in the dispersion direction provided by an embodiment of the present application. Figure 7 As shown, the optical switching device includes a first input port 701, a first collimator 702, a second input port 703, a second collimator 704, a first polarization conversion component 705, a second polarization conversion component 706, a third polarization separation component 707, a first lens 708, a second lens 709, a dispersion component 710, a third lens 711, a redirection component 712, and an output port 713. The first polarization conversion component 705 includes a first polarization separation component 7051 and a first half-wave plate 7052, and the second polarization conversion component 706 includes a second polarization separation component 7061 and a second half-wave plate 7062.

[0083] exist Figure 7 In the optical switching device shown, the switching direction or port direction is defined as the X direction, the wavelength direction or dispersion direction is defined as the Y direction (which is the direction of beam dispersion and separation), and the beam propagation direction is defined as the Z direction, with the X direction being perpendicular to both directions. The plane formed by the X and Z directions is defined as the port plane, and the plane formed by the Y and Z directions is defined as the dispersion plane. The angle at which a beam enters or exits an optical component is defined as the angle between the beam propagation direction and the normal to the optical component.

[0084] like Figure 7 As shown, a signal beam is input from a first input port 701, collimated by a first collimator 702, and the collimated signal beam is transmitted to a first polarization conversion component 705, wherein the signal beam is separated into two orthogonally polarized single polarization signals by a first polarization separation component 7051, namely, a signal beam in an S polarization state and a signal beam in a P polarization state. Wherein, the first polarization separation component 7051 includes a Wollaston prism or a coated polarization beam splitter (PBS). The two separated single polarization signals can have an angular difference or a displacement difference in the dispersion direction. In this embodiment, an angular difference is used as an example. The signal beam in the S polarization state is then converted into a signal beam in a P polarization state by a first 1 / 2 wave plate 7052. Subsequently, the two signal beams in the P polarization state are transmitted to a third polarization separation component 707.

[0085] A false light beam is input from the second input port 703 and collimated by the second collimator 704. The collimated false light beam is then transmitted to the second polarization conversion component 706, where the false light beam is separated by the second polarization separation component 7061 into two orthogonally polarized single polarization signals, namely, a false light beam in an S-polarization state and a false light beam in a P-polarization state. The second polarization separation component 7061 includes a Wollaston prism or a coated PBS. The two separated single polarization signals can have an angular difference or a displacement difference in the dispersion direction. In this embodiment, an angular difference is used as an example. The false light beam in the P-polarization state is then converted into a false light beam in the S-polarization state by the second 1 / 2 wave plate 7062. Subsequently, the two false light beams in the S-polarization state are transmitted to the third polarization separation component 707.

[0086] The polarization direction of the S polarization state is parallel to the port plane, and the polarization direction of the P polarization state is parallel to the dispersion plane. The third polarization separation component 707 passes the P polarization state signal beam and reflects the S polarization state dummy light beam. Subsequently, the propagation directions of the P polarization state signal beam and the S polarization state dummy light beam are consistent, where the consistent propagation directions include the same propagation directions or the angle between the propagation directions is less than a preset angle threshold.

[0087] Two P-polarized signal light beams and two S-polarized dummy light beams are transmitted to the dispersion component 710 through the first lens 708 and the second lens 709, wherein the first lens 708 is used to shape the light beams to change the spot size and convert the four light beams into parallel propagating light beams. The dispersion component 710 is located between the third polarization separation component 707 and the redirection component 712, and is used to separate the signal light beams and the dummy light beams into multiple signal sub-wavelength beams and multiple dummy light sub-wavelength beams in the dispersion plane, wherein the dispersion plane is the plane where the dispersion component 710 disperses the light beams into different propagation directions, and the multiple sub-wavelength beams exit the dispersion component 710 at different angles in the dispersion direction.

[0088] The sub-wavelength beams propagate to the redirection assembly 712 via a third lens 711, where the third lens 711 is configured to convert the angular differences in the dispersion directions of the sub-wavelength beams into positional differences in the dispersion directions. In the dispersion direction, two signal sub-wavelength beams of the same wavelength and polarization state are incident on the redirection assembly 712 at the same positions at different or symmetrical angles. Two dummy photon sub-wavelength beams of the same wavelength and polarization state are also incident on the redirection assembly 712 at the same positions at different or symmetrical angles, preferably symmetrical angles. In the dispersion direction, the signal sub-wavelength beams and dummy photon sub-wavelength beams of the same wavelength but different polarization states are incident on the redirection assembly 712 at the same positions. Positional consistency includes being at the same positions or having a distance between the positions that is less than a preset distance threshold. Signal sub-wavelength beams of different wavelengths are incident on different positions of the redirection assembly 712, and dummy photon sub-wavelength beams of different wavelengths are incident on different positions of the redirection assembly 712.

[0089] The angle at which the signal light beam and the dummy light beam enter the redirection component 712 in the port plane or port direction is not 0. At this time, the positions of the first input port 701 and the output port 713 in the port direction are different, wherein the angle at which the signal light beam and the dummy light beam enter the redirection component 711 in the port plane or port direction is the angle between the signal light beam and the dummy light beam and the normal of the redirection component 712.

[0090] Optionally, the redirection component 712 is located at the back focus of the third lens 711, the dispersion component 710 is located at the front focus of the third lens 711, and the dispersion component 710 is also located at the back focus of the first lens 708. The front focus of the first lens 708 coincides with the back focus of the first collimator 702.

[0091] Optionally, the second lens 709 is located between the first lens 708 and the third lens 711. The first lens 708 and the third lens 711 are cylindrical lenses, which have curvature in the dispersion direction and no curvature in the port direction. The second lens 709 is a cylindrical lens, which has curvature in the port direction and no curvature in the dispersion direction.

[0092] The redirection component 712 includes a plurality of light polarization conversion units, which can convert the polarization state of the light beam between the S polarization state and the P polarization state.

[0093] Optionally, the redirecting component 712 includes an LCOS based on a ferroelectric liquid crystal material, a bistable liquid crystal material, or a nematic liquid crystal material. The redirecting component 712 may also include an LCOS based on other liquid crystal materials, which are only examples.

[0094] Optionally, the redirection component 712 reflects all signal sub-wavelength beams in the P polarization state and reflects all dummy photon sub-wavelength beams in the S polarization state. Alternatively, the redirection component 712 converts the polarization state of all or part of the signal sub-wavelength beams in the P polarization state to the S polarization state and reflects the signal sub-wavelength beams, and converts the polarization state of all or part of the dummy photon sub-wavelength beams in the S polarization state to the P polarization state and reflects the dummy photon sub-wavelength beams.

[0095] After the reflected sub-wavelength beam passes through the third lens 711, the dispersion component 710, the second lens 709, the first lens 708, and the third polarization separation component 707, the sub-wavelength beam in the P polarization state passes through the third polarization separation component 707 and propagates to the output port 713 via the first polarization conversion component 705. The sub-wavelength beam in the S polarization state is isolated after being reflected by the third polarization separation component 707 and cannot propagate to the output port 713. In this embodiment, the redirection component 712 reflects the sub-wavelength beam in the dispersion direction. In other embodiments, the sub-wavelength beam can also be switched at other angles in the dispersion direction without limitation. The dispersion component 710 combines the signal sub-wavelength beams into a signal beam and combines the dummy light sub-wavelength beams into a dummy light beam.

[0096] In the dispersion direction, if two signal beams 1 and 2 of the same wavelength and polarization state are incident at symmetrical angles at the same position of the redirection component 712, then after switching, signal beam 1 propagates in the reverse direction along the optical path of the forward propagation of signal beam 2 to the output port, and signal beam 2 propagates in the reverse direction along the optical path of the forward propagation of signal beam 1 to the output port. In the dispersion direction, if two dummy light beams 1 and dummy light beams 2 of the same wavelength and polarization state are incident at symmetrical angles at the same position of the redirection component 712, then after switching, dummy light beam 1 propagates in the reverse direction along the optical path of the forward propagation of dummy light beam 2 to the output port, and dummy light beam 2 propagates in the reverse direction along the optical path of the forward propagation of dummy light beam 1 to the output port.) Wherein, forward propagation is defined as the propagation of a light beam from the first input port 701 or the second input port 703 to the redirection component 712, and reverse propagation is defined as the propagation of a light beam from the redirection component 712 to the output port 713.

[0097] In the above device, signal light is converted into P-polarized signal light after passing through the first polarization conversion component, and dummy light is converted into S-polarized dummy light after passing through the second polarization conversion component. When the redirection component converts the polarization state of the P-polarized signal light into S-polarized state and the polarization state of the S-polarized dummy light into P-polarized state, the P-polarized dummy light reflected by the redirection component passes through the third polarization separation component and is output to the output port. The S-polarized signal light reflected by the redirection component is isolated after being reflected by the third polarization separation component and cannot be output to the output port. This enables the upload of dummy light at the ROADM site, and the redirection component can convert or not convert the polarization state of the light beam. The above device can use LCOS that supports switching between two liquid crystal states, reducing response time and ensuring rapid upload of dummy light. In addition, the background losses such as LCOS reflection loss and liquid crystal absorption loss in the above device are relatively low, resulting in low losses to signal light or dummy light.

[0098] See also Figure 8 , Figure 8 for Figure 7Schematic diagram of the optical switching device in the port direction. Figure 8 As shown, a signal beam is input from a first input port 701, collimated by a first collimator 702, and then transmitted to a first polarization conversion component 705. The signal beam is then transmitted to a third polarization separation component 707 via a first polarization separation component 7051 and a first half-wave plate 7052, and then is incident on a redirection component 712 via a first lens 708, a second lens 709, a dispersion component 710, and a third lens 711. A dummy light beam is input from a second input port 703, collimated by a second collimator 704, and then transmitted to a second polarization conversion component 706. The dummy light beam is then transmitted to a second polarization separation component 7061 and a second half-wave plate 7062, and then is transmitted to a third polarization separation component 707 via a first lens 708, a second lens 709, a dispersion component 710, and a third lens 711, and then is incident on a redirection component 712.

[0099] from Figure 8 It can be seen that the first input port 701 and the output port 713 are located at different positions in the port direction, and the redirection component 712 is tilted in the port direction, so that the angle of the light beam incident on the redirection component 712 in the port direction is θ, where θ is not 0.

[0100] If the redirection component 712 does not convert the polarization states of the signal beam and the dummy light beam, the signal beam maintains its original P polarization state, and the dummy light beam maintains its original S polarization state. After being reflected by the redirection component 712, the P-polarized signal beam passes through the third lens 711, the dispersion component 710, the second lens 709, the first lens 708, the third polarization separation component 707, the first half-wave plate 7052, and the first polarization separation component 7051, and propagates to the output port 713. After being reflected by the redirection component 712, the S-polarized dummy light beam passes through the third lens 711, the dispersion component 710, the second lens 709, the first lens 708, and the third polarization separation component 707, and is isolated and prevented from propagating to the output port 713. The second lens 709 can be used to convert the propagation direction of the output beam of the redirection component 712 to be parallel to the input beam in the port direction.

[0101] If the redirection component 712 converts the polarization states of the signal beam and the dummy light beam, converting the P-polarized signal beam to an S-polarized state and converting the S-polarized dummy light beam to a P-polarized state, the P-polarized dummy light beam, after being reflected by the redirection component 712, passes through the third lens 711, the dispersion component 710, the second lens 709, the first lens 708, the third polarization separation component 707, the first half-wave plate 7052, and the first polarization separation component 7051, and then propagates to the output port 713. The S-polarized signal beam, after being reflected by the redirection component 712, passes through the third lens 711, the dispersion component 710, the second lens 709, the first lens 708, and the third polarization separation component 707, and is isolated and cannot propagate to the output port 713.

[0102] See also Figure 9 , Figure 9 Schematic diagram of the light spot distribution on the redirection component in the optical switching device provided in the embodiment of the present application. Figure 9 As shown, the light spots of beams with different wavelengths are positioned differently on the redirection component. For example, the light spot of a beam with a wavelength of λ_1 is positioned differently from the light spot of a beam with a wavelength of λ_m. The light spots of the signal light and the dummy light with the same wavelength are positioned identically on the redirection component. "Identical" positions include being identical or having a spacing less than a preset distance threshold. For example, the light spots of the signal light with a wavelength of λ_1 and the dummy light are positioned similarly.

[0103] Optionally, the redirection component in the optical switching device provided in the embodiment of the present application includes a polarization modulator. When the liquid crystal molecules in the polarization modulator are in a preset arrangement state, the polarization modulator converts the polarization state of the received light beam.

[0104] In one possible implementation, the polarization modulator includes an LCOS based on a ferroelectric liquid crystal material or a bistable liquid crystal material, or includes an LCOS based on other liquid crystal materials, which are merely examples.

[0105] In one possible embodiment, the liquid crystal molecules in the polarization modulator can rotate around the Z axis within the plane formed by the X and Y directions under voltage control, and the liquid crystal molecules switch between two arrangement states. This is only an example and does not limit the rotation direction of the liquid crystal molecules.

[0106] At a certain sub-wavelength position of LCOS, in the Z direction (beam propagation direction), the distance the light beam propagates in the liquid crystal molecule is d, the refractive index difference between the e-light and o-light of the liquid crystal molecule is Δn, the phase difference generated by LCOS for the P-polarization state light beam and the S-polarization state light beam is Φ, and the wavelength of the sub-wavelength light beam is λ. The relationship satisfied or close to it is: Here, n is an odd number that is not 0.

[0107] See also Figure 10 , Figure 10 Schematic diagram of the liquid crystal molecules in the polarization modulator in the first arrangement state. Figure 10 As shown, when the liquid crystal molecules in the polarization modulator are in the first arrangement state, the long axis direction of the liquid crystal molecules is parallel to the port direction (X direction) or the angle between them is less than a first preset threshold, wherein the first preset threshold can be, for example, 10 degrees. At this time, the long axis direction of the liquid crystal molecules is nearly parallel to the port direction.

[0108] When the liquid crystal molecules in the polarization modulator are in the first arrangement state, the polarization modulator does not convert the polarization state of the received light beam, and the polarization states of the signal light and the dummy light remain unchanged. The signal light maintains the original P polarization state, and the dummy light maintains the original S polarization state. The signal light is output from the output port, and the dummy light is isolated.

[0109] See also Figure 11 , Figure 11 Schematic diagram of the liquid crystal molecules in the polarization modulator in the second arrangement state. Figure 11 As shown, when the liquid crystal molecules in the polarization modulator are in the second arrangement state, the angle between the long axis direction of the liquid crystal molecules and the port direction (X direction) is 45 degrees or the difference from 45 degrees is less than a second preset threshold, where the second preset threshold can be 10 degrees, for example.

[0110] When the liquid crystal molecules in the polarization modulator are in the second alignment state, the polarization modulator converts the polarization state of the received light beam. The P-polarized signal light is converted to S-polarized signal light, and the S-polarized dummy light is converted to P-polarized dummy light. After the conversion, the dummy light is output from the output port, and the signal light is isolated.

[0111] As can be seen, this embodiment uses a polarization modulator to convert or not convert the polarization state of the light beam, eliminating the need for binary grating diffraction to deflect the light beam. This reduces losses to signal light or spurious light, including LCOS reflection losses and liquid crystal absorption losses. Furthermore, the use of LCOS with two alternate alignment states significantly reduces response time.

[0112] See also Figure 12 , Figure 12 This is a schematic diagram of another optical switching device in the dispersion direction provided by an embodiment of the present application. Figure 12As shown, the optical switching device includes a first input port 1201, a first collimator 1202, a second input port 1203, a second collimator 1204, a first polarization conversion component 1205, a second polarization conversion component 1206, a third polarization separation component 1207, a first lens 1208, a second lens 1209, a dispersion component 1210, a third lens 1211, a redirection component 1212, and an output port 1213. The first polarization conversion component 1205 includes a first polarization separation component 12051 and a first half-wave plate 12052, and the second polarization conversion component 1206 includes a second polarization separation component 12061 and a second half-wave plate 12062. The redirection component 1212 includes a third half-wave plate 12121 and a phase modulator 12122.

[0113] Figure 12 In the optical switching device shown, the third 1 / 2 wave plate 12121 is used to adjust the polarization direction of the signal light and the dummy light incident on the phase modulator 12122, so that the angle between the polarization direction of the signal light incident on the phase modulator 12122 and the fast axis of the phase modulator 12122 is a first angle, and the angle between the polarization direction of the dummy light incident on the phase modulator 12122 and the fast axis of the phase modulator 12122 is a second angle, and the first angle and the second angle are 45 degrees or the difference from 45 degrees is less than a preset threshold. The phase modulator 12122 is used to produce a phase change on the signal light and the dummy light after the polarization direction is adjusted by the third 1 / 2 wave plate 12121. When an odd multiple of π phase change is generated on the signal light and the dummy light, the polarization state of the signal light and the dummy light is converted. For descriptions of other optical components, please refer to Figure 7 The optical switching device shown is not described in detail here.

[0114] See also Figure 13 , Figure 13 for Figure 12 Schematic diagram of the optical switching device in the port direction. Figure 13 For instructions on the mid-light components, please refer to Figure 8 The optical switching device shown is not described in detail here.

[0115] In one possible implementation, the phase modulator 12122 includes an LCOS based on a nematic liquid crystal material. Under voltage control, the LCOS can produce a phase change of 0 or an even multiple of π on the light beam, or an odd multiple of π on the light beam. If the LCOS produces a phase change of 0 or an even multiple of π on the light beam, the polarization states of the signal light and the dummy light remain unchanged. The signal light maintains its original P polarization state, the dummy light maintains its original S polarization state, the signal light is output from the output port, and the dummy light is isolated. If the LCOS produces a phase change of an odd multiple of π on the light beam, the P-polarized signal light is converted to S-polarized signal light, and the S-polarized dummy light is converted to P-polarized dummy light. After the conversion, the dummy light is output from the output port, and the signal light is isolated.

[0116] See also Figure 14 , Figure 14 for Figure 12 Schematic diagram of the polarization direction of the light beam incident on the phase modulator. Figure 14 As shown, the angle between the polarization direction of the signal light incident on the phase modulator and the fast axis of the phase modulator is a first angle, and the angle between the polarization direction of the dummy light incident on the phase modulator and the fast axis of the phase modulator is a second angle. The first angle and the second angle are 45 degrees or the difference from 45 degrees is less than a preset threshold.

[0117] In one possible embodiment, when a phase change of 0 or an even multiple of π is generated for the signal light and the dummy light, the angle between the polarization direction of the signal light output phase modulator 12122 and the fast axis of the phase modulator 12122 is a first angle, and the angle between the polarization direction of the dummy light output phase modulator 12122 and the fast axis of the phase modulator 12122 is a second angle.

[0118] When an odd multiple of π phase change is generated for the signal light and the dummy light, the angle between the polarization direction of the signal light exiting the phase modulator 12122 and the fast axis of the phase modulator 12122 is a third angle, and the angle between the polarization direction of the dummy light exiting the phase modulator 12122 and the fast axis of the phase modulator 12122 is a fourth angle. The third angle is symmetrical to the first angle about the fast axis of the phase modulator 12122, and the fourth angle is symmetrical to the second angle about the fast axis of the phase modulator 12122. Figure 15 , Figure 15 for Figure 12 Schematic diagram of the polarization direction of the light beam exiting the phase modulator.

[0119] As can be seen, this embodiment uses a phase modulator to convert or not convert the polarization state of the light beam, eliminating the need for binary grating diffraction to deflect the light beam. This reduces losses to signal light or spurious light, including LCOS reflection loss and liquid crystal absorption loss. Furthermore, the response time is significantly reduced.

[0120] See also Figure 16 , Figure 16 This is a schematic diagram of another optical switching device in the dispersion direction provided by an embodiment of the present application. Figure 16 As shown, the optical switching device includes a first input port 1601, a first collimator 1602, a second input port 1603, a second collimator 1604, a first polarization conversion component 1605, a second polarization conversion component 1606, a third polarization separation component 1607, a first lens 1608, a second lens 1609, a dispersion component 1610, a third lens 1611, a redirection component 1612, a reflector 1613, and an output port 1614. The first polarization conversion component 1605 includes a first polarization separation component 16051 and a first half-wave plate 16052, and the second polarization conversion component 1606 includes a second polarization separation component 16061 and a second half-wave plate 16062.

[0121] See also Figure 17 , Figure 17 for Figure 16 Schematic diagram of the optical switching device in the port direction.

[0122] Combine Figure 16 and Figure 17 As shown in the optical switching device, it can be seen that the reflector 1613 is located after the second polarization conversion component 1606. The reflector 1613 is used to reflect the input light beam so that the light beam is incident on the third polarization separation component 1607. For the description of other optical components, please refer to Figure 7 and Figure 8 The optical switching device shown is not described in detail here.

[0123] See also Figure 18 , Figure 18 This is a schematic diagram of another optical switching device in the dispersion direction provided by an embodiment of the present application. Figure 18 As shown, the optical switching device includes a first input port 1801, a first collimator 1802, a second input port 1803, a second collimator 1804, a first polarization conversion component 1805, a second polarization conversion component 1806, a third polarization separation component 1807, a first lens 1808, a second lens 1809, a dispersion component 1810, a third lens 1811, a redirection component 1812, a circulator 1813, an isolator 1814, and an output port 1815. The first polarization conversion component 1805 includes a first polarization separation component 18051 and a first half-wave plate 18052, and the second polarization conversion component 1806 includes a second polarization separation component 18061 and a second half-wave plate 18062.

[0124] See also Figure 19 , Figure 19 for Figure 18 Schematic diagram of the optical switching device in the port direction.

[0125] Combine Figure 18 and Figure 19 As shown in the optical switching device, it can be seen that the angle of the light beam incident redirection component 1812 in the port plane or port direction is 0, the circulator 1813 is located between the first input port 1801 and the first polarization conversion component 1805, and the isolator 1814 is located between the second input port 1803 and the second polarization conversion component 1806. The circulator 1813 is used to transmit the light beam input from the first input port 1801 to the first polarization conversion component 1805, and transmit the light beam output from the first polarization conversion component 1805 to the output port 1815. The isolator 1814 is used to transmit the light beam input from the second input port 1803 to the second polarization conversion component 1806, and isolate the light beam output from the second polarization conversion component 1806. For descriptions of other optical components, please refer to Figure 7 and Figure 8 The optical switching device shown is not described in detail here.

[0126] See also Figure 20 , Figure 20 Schematic diagram of a ROADM provided in an embodiment of the present application. Figure 20 As shown, the ROADM includes a first WSS 2001 and a second WSS 2002. The first WSS 2001 is used to exchange signal light, and the second WSS 2002 includes any optical switching device provided in the embodiments of the present application. The second WSS 2002 is used to replace at least some wavelengths of the signal light with dummy optical signals. This enables rapid uploading of the dummy light at the ROADM site while minimizing the loss of the signal light or the dummy light.

[0127] See also Figure 21 , Figure 21 Schematic diagram of another ROADM provided in an embodiment of the present application. Figure 21 As shown, the ROADM includes a first WSS 2101, a second WSS 2102, a first optical amplifier 2103, a second optical amplifier 2104, and a third WSS 2105. The first optical amplifier 2103, the third WSS 2105, the first WSS 2101, and the second optical amplifier 2104 are arranged in order from front to back, with the second WSS 2102 located between the first WSS 2101 and the second optical amplifier 2104. The third WSS 2105 is used to download signal light, the first WSS 2101 is used to upload signal light, and the second WSS 2102 includes any one of the optical switching devices provided in the embodiments of the present application, for quickly uploading dummy light.

[0128] See also Figure 22 , Figure 22 Schematic diagram of another ROADM provided in an embodiment of the present application. Figure 22 As shown, the ROADM includes a first WSS 2201, a second WSS 2202, a first optical amplifier 2203, a second optical amplifier 2204, and a third WSS 2205. The first optical amplifier 2203, the third WSS 2205, the first WSS 2201, and the second optical amplifier 2204 are arranged in order from front to back, with the second WSS 2202 located after the second optical amplifier 2204. The third WSS 2205 is used to download signal light, the first WSS 2201 is used to upload signal light, and the second WSS 2202 includes any one of the optical switching devices provided in the embodiments of the present application, which is used to quickly upload dummy light.

[0129] See also Figure 23 , Figure 23 Schematic diagram of another ROADM provided in an embodiment of the present application. Figure 23 As shown, the ROADM includes a first WSS 2301, a second WSS 2302, a first optical amplifier 2303, a second optical amplifier 2304, and a third WSS 2305. The first optical amplifier 2303, the third WSS 2305, the first WSS 2301, and the second optical amplifier 2304 are arranged in order from front to back. The second optical amplifier 2304 includes a first-stage optical amplification unit 23041 and a second optical amplification unit 23042. Each optical amplification unit includes at least one section of bait fiber and at least one pump. The second WSS 2302 is located between the first-stage optical amplification unit 23041 and the second optical amplification unit 23042. The third WSS 2305 is used to download signal light, the first WSS 2301 is used to upload signal light, and the second WSS 2302 includes any one of the optical switching devices provided in the embodiments of the present application for rapidly uploading dummy light.

[0130] See also Figure 24 , Figure 24 Schematic diagram of another ROADM provided in an embodiment of the present application. Figure 24 As shown, the ROADM includes a first WSS 2401, a second WSS 2402, a first optical amplifier 2403, a second optical amplifier 2404, and a third WSS 2405. The first optical amplifier 2403, the third WSS 2405, the first WSS 2401, and the second optical amplifier 2404 are arranged in order from front to back, with the second WSS 2402 located before the third WSS 2405. The first WSS 2401 is used to upload signal light, the third WSS 2405 is used to download signal light, and the second WSS 2402 includes any optical switching device provided in the embodiments of the present application, which is used to quickly upload dummy light and quickly fill in dummy light when a fiber is broken.

[0131] See also Figure 25 , Figure 25Schematic diagram of another ROADM provided in an embodiment of the present application. Figure 25 As shown, the ROADM includes a first WSS 2501, a second WSS 2502, a first optical amplifier 2503, a second optical amplifier 2504, and a third WSS 2505. The first optical amplifier 2503, the third WSS 2505, the first WSS 2501, and the second optical amplifier 2504 are arranged in order from front to back, with the second WSS 2502 located before the first optical amplifier 2503. The first WSS 2501 is used to upload signal light, the third WSS 2505 is used to download signal light, and the second WSS 2502 includes any optical switching device provided in the embodiments of the present application, which is used to quickly upload dummy light and quickly fill in dummy light when a fiber is broken.

[0132] See also Figure 26 , Figure 26 Schematic diagram of another ROADM provided in an embodiment of the present application. Figure 26 As shown, the ROADM includes a first WSS 2601, a second WSS 2602, a first optical amplifier 2603, a second optical amplifier 2604, a third WSS 2605, and a fourth WSS 2606. The first optical amplifier 2603, the third WSS 2605, the first WSS 2601, and the second optical amplifier 2604 are arranged in order from front to back, with the second WSS 2602 located after the second optical amplifier 2604, and the fourth WSS 2606 located between the first optical amplifier 2603 and the third WSS 2605. The first WSS 2601 is used to upload signal light, and the third WSS 2605 is used to download signal light. The second WSS 2602 and the fourth WSS 2606 include any one of the optical switching devices provided in the embodiments of the present application. The second WSS 2602 is used to quickly upload dummy light, and the fourth WSS 2606 is used to quickly download or block dummy light.

[0133] See also Figure 27 , Figure 27 Schematic diagram of another ROADM provided in an embodiment of the present application. Figure 27As shown, the ROADM includes a first WSS 2701, a second WSS 2702, a first optical amplifier 2703, a second optical amplifier 2704, a third WSS 2705, and a fourth WSS 2706. The first optical amplifier 2703, the third WSS 2705, the first WSS 2701, and the second optical amplifier 2704 are arranged in order from front to back, with the second WSS 2702 located after the second optical amplifier 2704, and the fourth WSS 2706 located before the first optical amplifier 2703. The first WSS 2701 is used to upload signal light, the third WSS 2705 is used to download signal light, and the second WSS 2702 and the fourth WSS 2706 include any one of the optical switching devices provided in the embodiments of the present application. The second WSS 2702 is used to quickly upload dummy light, and the fourth WSS 2706 is used to quickly download or block dummy light.

[0134] See also Figure 28 , Figure 28 A schematic diagram of an optical switching method provided in an embodiment of the present application, the method being applied to an optical switching device, the optical switching device including a first input port, a second input port, a first polarization conversion component, a second polarization conversion component, a polarization separation component, a redirection component, and an output port, the method comprising:

[0135] S2801. Input a first light beam into a first input port.

[0136] S2802: Input a second light beam into the second input port.

[0137] S2803: The first polarization conversion component converts the polarization state of the input first light beam into the first polarization state.

[0138] S2804: The second polarization conversion component converts the polarization state of the input second light beam into a second polarization state, where polarization directions of the second polarization state and the first polarization state are orthogonal to each other.

[0139] S2805: The polarization separation component passes the first light beam in the first polarization state and reflects the second light beam in the second polarization state.

[0140] S2806, the redirection component reflects the first light beam in the first polarization state and the second light beam in the second polarization state; or converts the polarization state of the first light beam in the first polarization state into the second polarization state and reflects the first light beam in the second polarization state, and converts the polarization state of the second light beam in the second polarization state into the first polarization state and reflects the second light beam in the first polarization state; wherein, the light beam in the first polarization state reflected by the redirection component passes through the polarization separation component, and is output to the output port after being polarization-converted by the first polarization conversion component.

[0141] Optionally, the optical switching device further includes a dispersion component, which is located between the polarization separation component and the redirection component. The method further includes: the dispersion component separates the first light beam of the first polarization state and the second light beam of the second polarization state into multiple sub-wavelength light beams in a dispersion plane, the multiple sub-wavelength light beams of the first light beam are incident on different positions of the redirection component, and the multiple sub-wavelength light beams of the second light beam are incident on different positions of the redirection component, the sub-wavelength light beams of the first light beam and the sub-wavelength light beams of the second light beam with the same wavelength are incident on the redirection component at the same position, and the dispersion plane is the plane where the dispersion component disperses the light beams into different propagation directions.

[0142] Optionally, the optical switching device further includes a first lens, a second lens and a third lens, the second lens is located between the first lens and the third lens, the dispersion component is located at the back focus of the first lens and the front focus of the third lens, and the redirection component is located at the back focus of the third lens.

[0143] Optionally, the optical switching device further includes a reflector, which is located behind the second polarization conversion component. The method further includes: the reflector reflecting the second light beam in the second polarization state so that the second light beam in the second polarization state is incident on the polarization separation component.

[0144] Optionally, the redirection component reflects the first light beam in the first polarization state and the second light beam in the second polarization state; or converts the polarization state of the first light beam in the first polarization state into the second polarization state and reflects the first light beam in the second polarization state, and converts the polarization state of the second light beam in the second polarization state into the first polarization state and reflects the second light beam in the first polarization state, including: the redirection component reflects all sub-wavelength light beams in the first light beam in the first polarization state and all sub-wavelength light beams in the second light beam in the second polarization state; or converts the polarization state of all or part of the sub-wavelength light beams in the first light beam in the first polarization state into the second polarization state and reflects the sub-wavelength light beam after the polarization state conversion, and converts the polarization state of all or part of the sub-wavelength light beams in the second light beam in the second polarization state into the first polarization state and reflects the sub-wavelength light beam after the polarization state conversion; wherein the sub-wavelength light beam in the first polarization state reflected by the redirection component passes through the polarization separation component, and is output to the output port after being polarization-converted by the first polarization conversion component.

[0145] Optionally, the redirection component includes a polarization modulator, and the method further includes: when the liquid crystal molecules in the polarization modulator are in a preset arrangement state, the polarization modulator converts the polarization state of the received light beam.

[0146] Optionally, the redirection component includes a 1 / 2 wave plate and a phase modulator, and the method further includes: the 1 / 2 wave plate adjusts the polarization direction of the first light beam in the first polarization state and the second light beam in the second polarization state incident on the phase modulator, so that the angle between the polarization direction of the first light beam incident on the phase modulator and the fast axis of the phase modulator is a first angle, and the angle between the polarization direction of the second light beam incident on the phase modulator and the fast axis of the phase modulator is a second angle, and the first angle and the second angle are 45 degrees or the difference from 45 degrees is less than a preset threshold; the phase modulator generates a phase change on the first light beam and the second light beam after the polarization directions are adjusted by the 1 / 2 wave plate; when a phase change of an odd multiple of π is generated on the first light beam and the second light beam, the polarization state of the first light beam and the second light beam is converted.

[0147] Optionally, when a phase change of 0 or an even multiple of π is generated for the first light beam and the second light beam, the angle between the polarization direction of the first light beam exiting the phase modulator and the fast axis of the phase modulator is the first angle, and the angle between the polarization direction of the second light beam exiting the phase modulator and the fast axis of the phase modulator is the second angle; when a phase change of an odd multiple of π is generated for the first light beam and the second light beam, the angle between the polarization direction of the first light beam exiting the phase modulator and the fast axis of the phase modulator is a third angle, and the angle between the polarization direction of the second light beam exiting the phase modulator and the fast axis of the phase modulator is a fourth angle; the third angle is symmetrical with the first angle about the fast axis of the phase modulator, and the fourth angle is symmetrical with the second angle about the fast axis of the phase modulator.

[0148] Optionally, the first light beam includes a signal light beam, the second light beam includes a dummy light beam, and the first light beam and the second light beam are incident on the redirection component at the same position.

[0149] Optionally, the angle at which the first light beam and the second light beam are incident on the redirection component in the port plane or port direction is not 0, the positions of the first input port and the output port in the port direction are different, and the angle at which the first light beam and the second light beam are incident on the redirection component in the port plane or port direction is the angle between the first light beam and the second light beam and the normal of the redirection component.

[0150] Optionally, the angle at which the first light beam and the second light beam are incident on the redirection component in the port plane or port direction is 0, and the device further includes a circulator and an isolator, the circulator is located between the first input port and the first polarization conversion component, and the isolator is located between the second input port and the second polarization conversion component, and the method further includes: the circulator transmits the light beam input from the first input port to the first polarization conversion component, and transmits the light beam output from the first polarization conversion component to the output port; the isolator transmits the light beam input from the second input port to the second polarization conversion component, and isolates the light beam output from the second polarization conversion component.

[0151] Optionally, the reorienting component comprises liquid crystal on silicon (LCOS) based on ferroelectric liquid crystal material, bistable liquid crystal material or nematic liquid crystal material.

[0152] In the above method, the first light beam can be signal light, and the second light beam can be dummy light. The redirection component converts the polarization state of the signal light in the first polarization state to the second polarization state, and converts the polarization state of the dummy light in the second polarization state to the first polarization state. The dummy light in the first polarization state reflected by the redirection component passes through the polarization separation component and is output to the output port. Alternatively, the first light beam can be dummy light, and the second light beam can be signal light. The redirection component does not convert the polarization states of the signal light and the dummy light. The dummy light in the first polarization state reflected by the redirection component passes through the polarization separation component and is output to the output port. This enables the uploading of dummy light at a ROADM site. The redirection component can either convert or not convert the polarization state of the light beam. The optical switching device can utilize LCOS, which supports switching between two liquid crystal states. This reduces response time and enables fast uploading of dummy light. Furthermore, the background losses in the optical switching device, such as LCOS reflection loss and liquid crystal absorption loss, minimize losses to signal light or dummy light.

[0153] The embodiments of the present application also provide a method for optical energy attenuation. When signals of certain wavelengths suddenly drop out, such as when the laser light source is damaged or the EDFA fails, the WSSs of the cascaded ROADM sites need to be able to quickly upload dummy light of the same wavelength to fill the channels of these dropped signals. The WSS that uploads dummy light can use any of the optical switching devices provided in the embodiments of the present application. The optical switching device can isolate the old dummy light transmitted from the upper-level ROADM site and upload new local dummy light at the same time to avoid the continuous accumulation of dummy light energy on the link. In addition, the optical switching device used to quickly upload dummy light also needs to attenuate the optical energy of the new dummy light or the output port so that the power on the link remains balanced.

[0154] See also Figure 29 , Figure 29This is a schematic diagram of a method for light energy attenuation provided in an embodiment of the present application. Figure 29 As shown, the method includes:

[0155] S2901: The first WSS isolates old dummy light of the first wavelength and uploads new dummy light of the first wavelength.

[0156] Specifically, the first WSS may be any optical switching device provided in the embodiments of the present application.

[0157] S2902. The second WSS blocks the old false light of the first wavelength.

[0158] Specifically, the second WSS is located before the first WSS.

[0159] S2903: The first WSS attenuates the energy of the new false light of the first wavelength.

[0160] Optionally, the method for attenuating the energy of the new false light of the first wavelength includes: isolating the energy of a portion of the light spot of the new false light of the first wavelength by using LCOS. Figure 30 , Figure 30 A schematic diagram of attenuating the energy of new false light provided in an embodiment of the present application is shown as follows: Figure 30 As shown, the black area is the isolated energy.

[0161] It can be seen that the first WSS located before the second WSS has blocked the old false light of the first wavelength. Therefore, when the second WSS attenuates the energy of the new false light of the first wavelength, it will not transmit the energy of the old false light to the output port, thereby achieving effective attenuation of the light energy of the output port.

[0162] It should be understood that in various embodiments of the present application, the size of the sequence number of each process described above does not mean the order of execution, and the order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application. Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented with electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0163] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0164] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0165] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0166] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0167] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0168] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. An optical switching device, characterized in that: The device comprises a first input port, a second input port, a first polarization conversion component, a second polarization conversion component, a polarization separation component, a redirection component and an output port, wherein: The first input port is used to input a first light beam; The second input port is used to input a second light beam; The first polarization conversion component is used to convert the polarization state of the input first light beam into the first polarization state; The second polarization conversion component is used to convert the polarization state of the input second polarization state into a second polarization state, wherein the polarization directions of the second polarization state and the first polarization state are orthogonal to each other; The polarization separation component is configured to pass the first light beam in the first polarization state and reflect the second light beam in the second polarization state; The redirection component is configured to reflect a first light beam in the first polarization state and a second light beam in the second polarization state; or to convert the polarization state of the first light beam in the first polarization state into the second polarization state and reflect the first light beam in the second polarization state, and convert the polarization state of the second light beam in the second polarization state into the first polarization state and reflect the second light beam in the first polarization state; wherein the light beam in the first polarization state reflected by the redirection component passes through the polarization separation component and is polarization-converted by the first polarization conversion component before being output to the output port; The angle at which the first light beam and the second light beam are incident on the redirection component in the port plane or port direction is not 0, the positions of the first input port and the output port in the port direction are different, and the angle at which the first light beam and the second light beam are incident on the redirection component in the port plane or port direction is the angle between the first light beam and the second light beam and the normal of the redirection component.

2. The device according to claim 1, characterized in that The apparatus further includes a dispersive component positioned between the polarization separation component and the redirection component; The dispersion component is used to separate the first light beam in the first polarization state and the second light beam in the second polarization state into multiple sub-wavelength light beams in a dispersion plane. The multiple sub-wavelength light beams of the first light beam are incident on different positions of the redirection component, and the multiple sub-wavelength light beams of the second light beam are incident on different positions of the redirection component. The sub-wavelength light beams of the first light beam and the sub-wavelength light beams of the second light beam with the same wavelength are incident on the redirection component at the same position. The dispersion plane is the plane on which the dispersion component disperses the light beams into different propagation directions.

3. The device according to claim 2, characterized in that The device also includes a first lens, a second lens, and a third lens, wherein the second lens is located between the first lens and the third lens, the dispersion component is located at the back focus of the first lens and the front focus of the third lens, and the redirection component is located at the back focus of the third lens.

4. The device according to any one of claims 1 to 3, characterized in that The device further comprises a reflector, wherein the reflector is located after the second polarization conversion component; The reflector is configured to reflect the second light beam in the second polarization state so that the second light beam in the second polarization state is incident on the polarization separation component.

5. The device according to claim 2, characterized in that The redirection component is specifically used to: Reflect all sub-wavelength beams in the first light beam of the first polarization state and all sub-wavelength beams in the second light beam of the second polarization state; or convert the polarization state of all or part of the sub-wavelength beams in the first light beam of the first polarization state into the second polarization state and reflect the sub-wavelength beams after the polarization state conversion, and convert the polarization state of all or part of the sub-wavelength beams in the second light beam of the second polarization state into the first polarization state and reflect the sub-wavelength beams after the polarization state conversion; wherein the sub-wavelength beams of the first polarization state reflected by the redirection component pass through the polarization separation component, and are polarization-converted by the first polarization conversion component and then output to the output port.

6. The device according to any one of claims 1 to 3, characterized in that The redirection component includes a polarization modulator. When liquid crystal molecules in the polarization modulator are in a preset arrangement state, the polarization modulator converts the polarization state of the received light beam.

7. The device according to any one of claims 1 to 3, characterized in that The redirection component includes a 1 / 2 wave plate and a phase modulator; The half-wave plate is configured to adjust the polarization directions of the first light beam in the first polarization state and the second light beam in the second polarization state incident on the phase modulator, so that the angle between the polarization direction of the first light beam incident on the phase modulator and the fast axis of the phase modulator is a first angle, and the angle between the polarization direction of the second light beam incident on the phase modulator and the fast axis of the phase modulator is a second angle, and the first angle and the second angle are 45 degrees or the difference between the first angle and the second angle and 45 degrees is less than a preset threshold; The phase modulator is used to generate a phase change on the first light beam and the second light beam after the polarization direction is adjusted by the 1 / 2 wave plate; when a phase change of an odd multiple of π is generated on the first light beam and the second light beam, the polarization state of the first light beam and the second light beam is converted.

8. The device according to claim 7, characterized in that When a phase change of 0 or an even multiple of π is generated on the first light beam and the second light beam, the angle between the polarization direction of the first light beam exiting the phase modulator and the fast axis of the phase modulator is the first angle, and the angle between the polarization direction of the second light beam exiting the phase modulator and the fast axis of the phase modulator is the second angle; When a phase change of an odd multiple of π is generated in the first light beam and the second light beam, the angle between the polarization direction of the first light beam exiting the phase modulator and the fast axis of the phase modulator is a third angle, and the angle between the polarization direction of the second light beam exiting the phase modulator and the fast axis of the phase modulator is a fourth angle; the third angle is symmetrical with the first angle about the fast axis of the phase modulator, and the fourth angle is symmetrical with the second angle about the fast axis of the phase modulator.

9. The device according to any one of claims 1 to 3, characterized in that: The first light beam includes a signal light beam, the second light beam includes a dummy light beam, and the first light beam and the second light beam are incident on the redirection component at the same position.

10. The device according to any one of claims 1 to 3, characterized in that The reorienting component comprises liquid crystal on silicon (LCOS) based on ferroelectric liquid crystal material, bistable liquid crystal material or nematic liquid crystal material.

11. A reconfigurable optical add / drop multiplexing device ROADM, characterized in that: The ROADM includes a first wavelength selective switch (WSS) and a second WSS, wherein the first WSS is used to exchange signal light, and the second WSS includes the device according to any one of claims 1 to 10, which is used to replace at least part of the wavelength signal of the signal light with a dummy optical signal.

12. The ROADM according to claim 11, wherein: The ROADM also includes a first optical amplifier, a second optical amplifier and a third WSS. The first optical amplifier, the third WSS, the first WSS and the second optical amplifier are arranged in sequence from front to back. The second WSS is located between the first WSS and the second optical amplifier, or after the second optical amplifier, or between the first-stage optical amplification unit and the second-stage optical amplification unit included in the second optical amplifier, or between the first optical amplifier and the third WSS, or before the first optical amplifier.

13. An optical switching method, characterized in that: Applied to an optical switching device, the device includes a first input port, a second input port, a first polarization conversion component, a second polarization conversion component, a polarization separation component, a redirection component, and an output port, the method comprising: The first input port inputs a first light beam; The second input port inputs a second light beam; The first polarization conversion component converts the polarization state of the input first light beam into a first polarization state; The second polarization conversion component converts the polarization state of the input second light beam into a second polarization state, wherein the polarization directions of the second polarization state and the first polarization state are orthogonal to each other; The polarization separation component passes the first light beam in the first polarization state and reflects the second light beam in the second polarization state; The redirecting component reflects the first light beam in the first polarization state and the second light beam in the second polarization state; or converts the polarization state of the first light beam in the first polarization state into the second polarization state and reflects the first light beam in the second polarization state, and converts the polarization state of the second light beam in the second polarization state into the first polarization state and reflects the second light beam in the first polarization state; wherein the light beam in the first polarization state reflected by the redirecting component passes through the polarization separation component and is polarization-converted by the first polarization conversion component before being output to the output port; The angle at which the first light beam and the second light beam are incident on the redirection component in the port plane or port direction is not 0, the positions of the first input port and the output port in the port direction are different, and the angle at which the first light beam and the second light beam are incident on the redirection component in the port plane or port direction is the angle between the first light beam and the second light beam and the normal of the redirection component.

14. The method according to claim 13, wherein: The apparatus further includes a dispersive component positioned between the polarization separation component and the redirection component, and the method further includes: The dispersion component separates the first light beam in the first polarization state and the second light beam in the second polarization state into multiple sub-wavelength light beams in a dispersion plane. The multiple sub-wavelength light beams of the first light beam are incident on different positions of the redirection component, and the multiple sub-wavelength light beams of the second light beam are incident on different positions of the redirection component. The sub-wavelength light beams of the first light beam and the sub-wavelength light beams of the second light beam with the same wavelength are incident on the redirection component at the same position. The dispersion plane is the plane on which the dispersion component disperses the light beams into different propagation directions.

15. The method according to claim 14, characterized in that The device also includes a first lens, a second lens, and a third lens, wherein the second lens is located between the first lens and the third lens, the dispersion component is located at the back focus of the first lens and the front focus of the third lens, and the redirection component is located at the back focus of the third lens.

16. The method according to any one of claims 13 to 15, characterized in that: The device further includes a reflector, wherein the reflector is located after the second polarization conversion component, and the method further includes: The reflector reflects the second light beam in the second polarization state so that the second light beam in the second polarization state is incident on the polarization separation component.

17. The method according to claim 14, characterized in that The redirecting component reflects a first light beam in the first polarization state and a second light beam in the second polarization state; or converts the polarization state of the first light beam in the first polarization state into the second polarization state and reflects the first light beam in the second polarization state, converts the polarization state of the second light beam in the second polarization state into the first polarization state and reflects the second light beam in the first polarization state, comprising: The redirection component reflects all sub-wavelength beams in the first light beam of the first polarization state and all sub-wavelength beams in the second light beam of the second polarization state; or converts the polarization state of all or part of the sub-wavelength beams in the first light beam of the first polarization state into the second polarization state and reflects the sub-wavelength beams that have undergone the polarization conversion, and converts the polarization state of all or part of the sub-wavelength beams in the second light beam of the second polarization state into the first polarization state and reflects the sub-wavelength beams that have undergone the polarization conversion; wherein the sub-wavelength beams of the first polarization state reflected by the redirection component pass through the polarization separation component, and are polarization-converted by the first polarization conversion component and then output to the output port.

18. The method according to any one of claims 13 to 15, characterized in that: The redirecting component includes a polarization modulator, and the method further includes: When the liquid crystal molecules in the polarization modulator are in a preset arrangement state, the polarization modulator converts the polarization state of the received light beam.

19. The method according to any one of claims 13 to 15, characterized in that: The redirection component includes a 1 / 2 wave plate and a phase modulator, and the method further includes: The half-wave plate adjusts the polarization directions of the first light beam in the first polarization state and the second light beam in the second polarization state incident on the phase modulator, so that the angle between the polarization direction of the first light beam incident on the phase modulator and the fast axis of the phase modulator is a first angle, and the angle between the polarization direction of the second light beam incident on the phase modulator and the fast axis of the phase modulator is a second angle, and the first angle and the second angle are 45 degrees or the difference between the first angle and the second angle and 45 degrees is less than a preset threshold; The phase modulator generates a phase change on the first light beam and the second light beam after the polarization direction is adjusted by the 1 / 2 wave plate; when an odd multiple of π phase change is generated on the first light beam and the second light beam, the polarization state of the first light beam and the second light beam is converted.

20. The method according to claim 19, characterized in that When a phase change of 0 or an even multiple of π is generated on the first light beam and the second light beam, the angle between the polarization direction of the first light beam exiting the phase modulator and the fast axis of the phase modulator is the first angle, and the angle between the polarization direction of the second light beam exiting the phase modulator and the fast axis of the phase modulator is the second angle; When a phase change of an odd multiple of π is generated in the first light beam and the second light beam, the angle between the polarization direction of the first light beam exiting the phase modulator and the fast axis of the phase modulator is a third angle, and the angle between the polarization direction of the second light beam exiting the phase modulator and the fast axis of the phase modulator is a fourth angle; the third angle is symmetrical with the first angle about the fast axis of the phase modulator, and the fourth angle is symmetrical with the second angle about the fast axis of the phase modulator.

21. The method according to any one of claims 13 to 15, characterized in that The first light beam includes a signal light beam, the second light beam includes a dummy light beam, and the first light beam and the second light beam are incident on the redirection component at the same position.

22. The method according to any one of claims 13 to 15, characterized in that The reorienting component comprises liquid crystal on silicon (LCOS) based on ferroelectric liquid crystal material, bistable liquid crystal material or nematic liquid crystal material.

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