WO2024066614A1 - 光调制装置、波长选择开关和光通信设备 - Google Patents

光调制装置、波长选择开关和光通信设备 Download PDF

Info

Publication number
WO2024066614A1
WO2024066614A1 PCT/CN2023/104940 CN2023104940W WO2024066614A1 WO 2024066614 A1 WO2024066614 A1 WO 2024066614A1 CN 2023104940 W CN2023104940 W CN 2023104940W WO 2024066614 A1 WO2024066614 A1 WO 2024066614A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
light
optical
light beam
refractive index
Prior art date
Application number
PCT/CN2023/104940
Other languages
English (en)
French (fr)
Inventor
李腾浩
李世强
韩荦
Original Assignee
华为技术有限公司
鹏城实验室
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 华为技术有限公司, 鹏城实验室 filed Critical 华为技术有限公司
Publication of WO2024066614A1 publication Critical patent/WO2024066614A1/zh

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
    • G02B6/29304—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
    • G02B6/29304—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating
    • G02B6/29316—Light guides comprising a diffractive element, e.g. grating in or on the light guide such that diffracted light is confined in the light guide
    • G02B6/29317—Light guides of the optical fibre type
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/35—Optical coupling means having switching means
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1347—Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells

Definitions

  • the present application relates to the field of optical modulation technology, and in particular to an optical modulation device, a wavelength selective switch (WSS) and optical communication equipment.
  • WSS wavelength selective switch
  • Spatial light modulation technology is a technology that can modulate the spatial distribution of light, usually implemented using a light modulation device. Under the control of an external signal, the light modulation device can change the amplitude (or intensity), phase or polarization state of the light distribution in space.
  • the light modulation device generally includes a spatial light modulator.
  • the spatial light modulator includes a plurality of modulation units arranged in an array, each of which can modulate the received light beam under the control of an external signal.
  • a first light beam and a second light beam with the same wavelength are incident on the same modulation unit at different incident angles at the same time, the modulated first light beam and the second light beam will be emitted in different directions.
  • the light modulation device can control the emission directions of the modulated first light beam and the second light beam by changing the modulation related parameters of the modulation unit, and the control method is relatively simple.
  • the present application provides an optical modulation device, a WSS and an optical communication device, which can increase the control method of the emission direction of the light beam.
  • the present application provides a light modulation device.
  • the light modulation device includes a spatial light modulator and an optical adjustment layer.
  • the spatial light modulator includes a plurality of modulation units arranged in an array.
  • the optical adjustment layer includes a plurality of adjustment units arranged in an array, and the plurality of adjustment units correspond to one of the plurality of modulation units respectively.
  • a first adjustment unit among the plurality of adjustment units is configured to switch between a first state and a second state under the action of an excitation signal, and the first adjustment unit is any one of the plurality of adjustment units.
  • the first adjustment unit is used to guide a received first light beam to a first modulation unit in the first state, and the first modulation unit is a modulation unit corresponding to the first adjustment unit among the plurality of modulation units.
  • the first modulation unit is used to modulate the first light beam from the first adjustment unit, and emit the modulated first light beam along a first direction; or, the first adjustment unit is used to emit the received second light beam along the first direction in the second state.
  • the wavelength of the second light beam is the same as the wavelength of the first light beam, and the incident angle of the second light beam incident on the first adjustment unit is different from the incident angle of the first light beam incident on the first adjustment unit.
  • the light modulation device provided in the present application can also control the emission direction of the light beam by controlling the state of the first adjustment unit, thereby increasing the control method of the emission direction of the light beam.
  • the first adjustment unit is further used to direct the received second light beam to the first modulation unit in the first state.
  • the first modulation unit is further used to modulate the second light beam from the first adjustment unit, and emit the modulated second light beam in a second direction. Since the wavelengths of the first light beam and the second light beam are the same, under the same modulation-related parameters, the deflection angles of the modulated first light beam and the modulated second light beam are the same, but since the incident angles of the first light beam and the second light beam are different, the emission directions of the modulated first light beam and the modulated second light beam are different.
  • the light modulation device can work when the second light beam is always incident, so that when the second light beam needs to be emitted in the first direction, the second light beam can be quickly switched to be emitted from the first direction. This avoids the second light beam being incident on the light modulation device when it is needed to be emitted in the first direction, resulting in a long waiting time.
  • the first state is a transmissive state and the second state is a reflective state. In other examples, the first state is a reflective state and the second state is a reflective state.
  • the second state is the transmission state.
  • the transmission state and the reflection state are relative. The transmittance of the first adjustment unit in the transmission state is higher than that in the reflection state, and the reflectance of the first adjustment unit in the transmission state is higher than that in the reflection state. Considering the light effect, the closer the transmittance in the transmission state is to 100%, the better, and the closer the reflectance in the reflection state is to 100%, the better.
  • the first adjustment unit includes a diffraction grating structure
  • the diffraction grating structure includes a refractive index variable layer and an optical medium layer stacked on the spatial light modulator.
  • the refractive index variable layer is configured to have a first refractive index when the first adjustment unit is in the first state, and to have a second refractive index when the first adjustment unit is in the second state, and the first refractive index and the second refractive index are different.
  • the refractive index of the optical medium layer matches the first refractive index or the second refractive index.
  • variable refractive index layer includes a plurality of first block structures arranged in an array
  • the optical medium layer includes a plurality of second block structures arranged in an array, and the second block structures are connected to the first block structures in a one-to-one correspondence.
  • the optical medium layer and the variable refractive index layer when the refractive index of the optical medium layer matches the refractive index of the variable refractive index layer, the optical medium layer and the variable refractive index layer form a reflective diffraction grating; and when the refractive index of the optical medium layer does not match the refractive index of the variable refractive index layer, the optical medium layer and the variable refractive index layer form a transmissive diffraction grating.
  • the optical medium layer and the variable refractive index layer when the refractive index of the optical medium layer matches the refractive index of the variable refractive index layer, the optical medium layer and the variable refractive index layer form a transmissive diffraction grating; and when the refractive index of the optical medium layer does not match the refractive index of the variable refractive index layer, the optical medium layer and the variable refractive index layer form a reflective diffraction grating.
  • the difference between the first refractive index and the second refractive index is greater than 0.5.
  • the difference in refractive index can switch the diffraction grating structure between a reflective diffraction grating and a transmissive diffraction grating, thereby switching the first adjustment unit between the first state and the second state.
  • the optical medium layer and the variable refractive index layer are formed into a one-dimensional grating structure.
  • the plurality of first block structures are arranged in a one-dimensional array
  • the first block structure and the second block structure are both long strip structures
  • the length direction of the first block structure is perpendicular to the arrangement direction of the plurality of first block structures and perpendicular to the stacking direction of the variable refractive index layer and the optical medium layer.
  • the optical medium layer and the variable refractive index layer are formed into a two-dimensional grating structure.
  • the plurality of first block structures are arranged in a two-dimensional array
  • the first block structure and the second block structure are both columnar structures
  • the length direction of the first block structure is perpendicular to any arrangement direction of the plurality of first block structures and parallel to the stacking direction of the variable refractive index layer and the optical medium layer.
  • the variable refractive index layer is formed of a phase change material, and the phase change of the phase change material causes the refractive index of the variable refractive index layer to change.
  • the phase change material is selected from any one of the following materials: antimony selenide, antimony sulfide, tellurium sulfide, germanium antimony telluride, antimony tritelluride, germanium tellurium sulfide, germanium arsenic sulfide, germanium tellurium selenium, and germanium antimony selenium telluride.
  • the phase change speed of the phase change material is fast, which is conducive to realizing the rapid switching of the working state of the adjustment unit (i.e., the aforementioned first state and second state).
  • the optical medium layer is made of a transparent conductive material.
  • the optical medium layer is made of a transparent conductive material, under the action of an excitation signal, the optical medium layer generates heat, causing the phase state of the phase change material to change, thereby causing the refractive index of the refractive index variable layer to change.
  • the optical medium layer serves as a part of the diffraction grating structure and also plays a conductive role, which is conducive to simplifying the structure of the adjustment unit.
  • the optical medium layer can be made of materials such as graphene, indium tin oxide or doped silicon.
  • the optical medium layer is made of a transparent insulating material.
  • the adjustment unit further includes a transparent conductive layer, which is located on the surface of the optical medium layer or on the surface of the variable refractive index layer. Under the action of the excitation signal, the transparent conductive layer generates heat, which is transferred to the variable refractive index layer to change the phase state of the phase change material, thereby changing the refractive index of the variable refractive index layer.
  • the optical medium layer can be made of any one of the following materials: silicon, titanium dioxide, silicon nitride, silicon carbide and silicon oxynitride.
  • the optical adjustment layer further comprises a substrate, and the plurality of adjustment units are arranged in an array on a first surface of the substrate.
  • the second surface of the substrate is directly or indirectly connected to the spatial light modulator.
  • the adjustment units are first manufactured on the substrate, and then the substrate is connected to the spatial light modulator, which is convenient for manufacturing and can avoid adverse effects on the spatial modulator during the manufacturing process of the adjustment units.
  • the optical adjustment layer further includes a covering layer, which is filled between any two adjacent first block structures and any two adjacent second block structures and covers the variable refractive index layer.
  • the covering layer can protect the variable refractive index layer and the optical medium layer, and the surface of the covering layer is flat, which is convenient for connection with other surfaces.
  • the optical adjustment layer further comprises an anti-reflection film layer, and the anti-reflection film layer is located on the cover layer.
  • the anti-reflection film layer is used to increase the transmittance of the optical communication band (such as C band, L band or S band) to which the incident light beam belongs.
  • the first state is a transmission state
  • the second state is a reflection state.
  • the optical adjustment layer is connected to a surface of the spatial light modulator.
  • the first state is a reflective state
  • the second state is a transmissive state
  • the light modulation device further includes a turning prism and a reflective element, and the turning prism is located on the incident light path of the first light beam and the second light beam.
  • the first surface of the turning prism is connected to the surface of the spatial light modulator
  • the second surface of the turning prism is connected to the optical adjustment layer
  • the reflective element and the spatial light modulator are respectively located on both sides of the optical adjustment layer.
  • the turning prism is a right-angle prism
  • the first surface of the turning prism is a right-angle surface
  • the second surface of the turning prism is an inclined surface
  • the light modulation device further includes: a polarization beam splitter and a reflective wave plate.
  • the polarization beam splitter is located on the incident light path of the second light beam, and the polarization beam splitter is used to transmit the second light beam to the optical adjustment layer.
  • the first light beam is a linearly polarized light with a first polarization direction.
  • the polarization beam splitter is also used to split the fourth light beam into the first light beam and a third light beam, the first light beam is a linearly polarized light with the first polarization direction, and the third light beam is a linearly polarized light with a second polarization direction; the first light beam is emitted to the optical adjustment layer, and the third light beam is emitted to the reflective wave plate, and the reflective wave plate is used to convert the third light beam into a linearly polarized light with the first polarization direction and then emit it to the spatial light modulator.
  • the fourth light beam is an optical signal after being transmitted over a long distance through an optical fiber
  • the fourth light beam is firstly split into linear polarized lights with different polarization directions through a polarization beam splitter, and the linear polarized light with a first polarization direction is directly emitted to a spatial light modulator, and the linear polarized light with a second polarization direction is converted into linear polarized light with the first polarization direction by a reflective wave plate and then emitted to the spatial light modulator, so that the fourth light beam can be polarization multiplexed, thereby simplifying the optical design.
  • the spatial light modulation device further comprises a pre-deflection layer, the pre-deflection layer comprises a plurality of deflection units arranged in an array, the plurality of deflection units correspond to the plurality of adjustment units one by one.
  • a first deflection unit among the plurality of deflection units corresponding to the first adjustment unit is located on an optical path between the first adjustment unit and the first modulation unit, the first deflection unit being used to deflect the light of the first adjustment unit by a set angle and then emit it to the first modulation unit.
  • any deflection unit among the multiple deflection units includes a blazed grating, a diffraction optical element (DOE), a grating structure with a gradient pitch, or a grating structure with a gradient duty cycle.
  • DOE diffraction optical element
  • the spatial light modulator is any one of a liquid crystal on silicon (LCOS) modulator, a micro-electro-mechanical system (MEMS) modulator and a liquid crystal (LC) modulator.
  • LCOS liquid crystal on silicon
  • MEMS micro-electro-mechanical system
  • LC liquid crystal
  • the present application provides a WSS, wherein the wavelength selective switch comprises an interface unit, a wavelength splitting unit and an optical modulation device.
  • the interface unit comprises M input ports and N output ports, wherein the M input ports and the N output ports are arranged in an array, wherein M and N are both integers, and at least one of M and N is greater than 1.
  • the optical modulation device is any of the aforementioned optical modulation devices.
  • the wavelength splitting unit is used to split the light beams from the M input ports to obtain light beams of multiple wavelengths, and output the light beams of different wavelengths to different adjustment units of the optical modulation device; and output the light beam emitted by the optical modulation device along the first direction to one of the N output ports.
  • the wave splitting unit is further used to output the light beam emitted by the optical modulator along the second direction to a position outside the N output ports, so that the light beam emitted by the optical modulator along the second direction cannot be emitted from the WSS.
  • the present application provides an optical communication device.
  • the optical communication device includes a dummy light source and any one of the aforementioned WSSs, wherein the dummy light source is connected to a first input port of the WSS, the dummy light source is used to provide dummy light, the wavelength range of the dummy light at least partially overlaps with the operating wavelength range of the wavelength selective switch, and the second light beam is a part of the dummy light.
  • the wavelength range of the dummy light includes the working wavelength range of the WSS.
  • any input port connected to the WSS loses wavelength, it can be filled with dummy light of the corresponding wavelength provided by the dummy light source.
  • FIG1 is a schematic diagram of the structure of an optical modulation device provided in an embodiment of the present application.
  • FIG2 is a schematic diagram of a top view of an optical adjustment layer provided in an embodiment of the present application.
  • FIG3 is a schematic diagram of an enlarged structure of an adjustment unit provided in an embodiment of the present application.
  • FIG4 is a schematic diagram of a cross-sectional structure of the adjustment unit shown in FIG3 ;
  • FIG5 is an enlarged structural schematic diagram of another adjustment unit provided in an embodiment of the present application.
  • FIG6 is a schematic diagram of a cross-sectional structure of the adjustment unit shown in FIG5 ;
  • FIG7 is an enlarged structural diagram of another adjustment unit provided in an embodiment of the present application.
  • FIG8 is a schematic diagram of a cross-sectional structure of the adjustment unit shown in FIG7 ;
  • FIG9 is a schematic structural diagram of another light modulation device provided in an embodiment of the present application.
  • FIG10 is a schematic diagram of a top view of a pre-deflection layer provided in an embodiment of the present application.
  • FIG11 is an enlarged structural schematic diagram of a deflection unit provided in an embodiment of the present application.
  • FIG12 is a schematic diagram of a cross-sectional structure of a deflection unit provided in an embodiment of the present application.
  • FIG13 is a schematic cross-sectional view of another deflection unit provided in an embodiment of the present application.
  • FIG14 is a schematic diagram of a cross-sectional structure of another deflection unit provided in an embodiment of the present application.
  • FIG15 is a schematic diagram of the working process of the light modulation device shown in FIG9 in the first state
  • FIG16 is a schematic diagram of the working process of the light modulation device shown in FIG9 in the second state
  • FIG17 is a schematic structural diagram of another optical modulation device provided in an embodiment of the present application.
  • FIG18 is a schematic structural diagram of another optical modulation device provided in an embodiment of the present application.
  • FIG19 is a schematic cross-sectional view of another deflection unit provided in an embodiment of the present application.
  • FIG20 is a schematic diagram of the working process of the light modulation device shown in FIG18 in the first state
  • FIG21 is a schematic diagram of the working process of the light modulation device shown in FIG18 in the second state
  • FIG22 is a schematic diagram of the structure of another optical modulation device provided in an embodiment of the present application.
  • FIG23 is a schematic diagram of a cross-sectional structure of another deflection unit provided in an embodiment of the present application.
  • FIG24 is a schematic diagram of the working process of the light modulation device shown in FIG22 in the first state
  • FIG25 is a schematic diagram of the working process of the light modulation device shown in FIG22 in the second state
  • FIG26 is a schematic diagram of the structure of another optical modulation device provided in an embodiment of the present application.
  • FIG27 is a schematic diagram of the working process of the light modulation device shown in FIG26 in the first state
  • FIG28 is a schematic diagram of the working process of the light modulation device shown in FIG26 in the second state
  • FIG29 is a schematic diagram of a WSS in a working state provided by an embodiment of the present application.
  • FIG30 is a side view of FIG29
  • FIG31 is a schematic diagram of a WSS provided in an embodiment of the present application in another working state
  • FIG32 is a side view of FIG31
  • FIG33 is a schematic diagram of the structure of another optical communication device provided in an embodiment of the present application.
  • FIG34 is a schematic diagram of the structure of another optical communication device provided in an embodiment of the present application.
  • the embodiment of the present application provides a light modulation device, which combines an optical adjustment layer with a spatial light modulator to change the state of the optical adjustment layer and flexibly control the emission position of a light beam.
  • Fig. 1 is a schematic diagram of the structure of a light modulation device provided in an embodiment of the present application. As shown in Fig. 1 , the light modulation device includes: a spatial light modulator 10 and an optical adjustment layer 20 .
  • the spatial light modulator 10 includes a plurality of modulation units 10a arranged in an array.
  • the plurality of modulation units 10a in the spatial light modulator 10 may be arranged in a one-dimensional array, such as a row of multiple columns, or a column of multiple rows; or, the plurality of modulation units 10a in the spatial light modulator 10 may be arranged in a two-dimensional array, such as a plurality of rows and columns.
  • the optical adjustment layer 20 includes a plurality of adjustment units 20a arranged in an array.
  • the plurality of adjustment units 20a correspond one-to-one to the plurality of modulation units 10a. That is, the arrangement of the plurality of adjustment units 20a is the same as the arrangement of the plurality of modulation units 10a, and each adjustment unit 20a corresponds to one modulation unit 10a.
  • Each adjustment unit 20a is configured to switch between a first state and a second state under the action of an excitation signal.
  • the excitation signal includes but is not limited to an electrical signal or a thermal signal.
  • the first adjustment unit is any adjustment unit in the optical adjustment layer.
  • the first adjustment unit is used to direct the received first light beam B1 to the first modulation unit in the first state
  • the first modulation unit is a modulation unit corresponding to the first adjustment unit among the multiple adjustment units.
  • the first modulation unit is used to modulate the first light beam B1 from the corresponding first adjustment unit, and emit the modulated first light beam B1 along the first direction P1.
  • the first adjustment unit is used to emit the received second light beam B2 along the first direction P1 in the second state.
  • the wavelength of the second light beam B2 is the same as the wavelength of the first light beam B1, and the incident angle ⁇ 2 of the second light beam B2 incident on the first adjustment unit is different from the incident angle ⁇ 1 of the first light beam B1 incident on the first adjustment unit.
  • the first state is a transmission state, and the first adjustment unit transmits the first light beam B1 to the first modulation unit;
  • the second state is a reflection state, and the first adjustment unit reflects the second light beam B2 along the first direction.
  • the light modulation device provided in the present application can also control the emission direction of the light beam by controlling the state of the first adjustment unit, thereby increasing the control method of the emission direction of the light beam.
  • the first adjustment unit is further used to direct the received second light beam B2 to the first modulation unit in the first state.
  • the first modulation unit is also used to emit the modulated second light beam B2 along a second direction P2, and the second direction P2 is different from the first direction P1. Since the wavelengths of the first light beam and the second light beam are the same, under the same modulation-related parameters, the deflection angles of the modulated first light beam and the modulated second light beam are the same, but since the incident angles of the first light beam and the second light beam are different, the emission directions of the modulated first light beam and the modulated second light beam are different.
  • the light modulation device can work when the second light beam B2 is always incident, so as to quickly switch the second light beam B2 to be emitted from the first direction when the second light beam needs to be emitted to the first direction. This avoids the second light beam B2 being incident on the light modulation device when the second light beam B2 needs to be emitted to the first direction, resulting in a long waiting time.
  • a spatial light modulator is a device that modulates the spatial distribution of light. Under the control of an external signal (electrical drive signal), it changes the amplitude (or intensity), phase, polarization state, etc. of the spatial light distribution.
  • the spatial light modulator 10 in the embodiment of the present application is mainly used to change the phase of the spatial light distribution and can be called a phase-type spatial light modulator.
  • the spatial light modulator 10 includes a reflective spatial light modulator and a transmissive spatial light modulator.
  • the reflective spatial light modulator is used as an example in Fig. 1.
  • the spatial light modulator 10 may also be a transmissive spatial light modulator.
  • Reflective spatial light modulators include, but are not limited to, LCOS modulators and MEMS modulators.
  • Transmissive spatial light modulators include, but are not limited to, LC modulators, etc.
  • the first state is a reflection state, and the first adjustment unit reflects the first light beam to the first modulation unit; the second state is a transmission state, and the first adjustment unit transmits the second light beam to the first direction.
  • the number of modulation units 10a included in the spatial light modulator 10 may be greater than the number of modulation units 20a in the optical adjustment layer 20, as long as each modulation unit 20a corresponds to one modulation unit 10a.
  • the modulation unit 20a corresponds to the modulation unit 10a, which means that the positional relationship between the corresponding modulation unit 20a and the modulation unit 10a can be satisfied, and when the light beam is incident on the modulation unit 20a in the first state, the modulation unit 20a can guide the light beam to the corresponding modulation unit 10a.
  • the transmission state and the reflection state are relative, the transmittance of the first adjustment unit in the transmission state is higher than the transmittance of the first adjustment unit in the reflection state, and the reflectance of the first adjustment unit in the transmission state is higher than the reflectance of the first adjustment unit in the reflection state.
  • the transmittance in the transmission state and the reflectance in the reflection state are determined by the film layer structure parameters and refractive index parameters in the adjustment unit. For example, it is determined by the structure parameters and refractive index parameters of the optical medium layer and the structure parameters and refractive index parameters of the variable refractive index layer described below.
  • Fig. 2 is a schematic diagram of a top view of an optical adjustment layer provided in an embodiment of the present application.
  • the optical adjustment layer 20 includes a plurality of adjustment units 20a arranged along a first direction. The state of each adjustment unit 20a can be controlled individually.
  • each adjustment unit 20a is used to incident light beams of different wavelengths.
  • the wavelengths of the incident light beams incident to each adjustment unit 20a are ⁇ 1 ⁇ M respectively.
  • M is an integer and is greater than 1.
  • the ellipse in each adjustment unit 20a in Figure 2 represents the light spot formed by the incident light beams of different wavelengths. It can be seen from Figure 2 that the arrangement direction of the light spots formed by the incident light beams of different wavelengths is the same as the arrangement direction of the multiple adjustment units 20a, and therefore, the first direction can also be referred to as the wavelength arrangement direction.
  • the band of 1260nm ⁇ 1625nm belongs to the low-loss wavelength region. Light with wavelengths in this wavelength region is suitable for transmission in optical fibers.
  • This wavelength region is divided into five bands, namely the conventional (conventional, C) band, long-wavelength (long-wavelength, L) band, short-wavelength (short-wavelength, S) band, original (orignal, O) band and extended (extended, E) band.
  • the C band shows the lowest loss, usually 1530nm ⁇ 1565nm.
  • the L band is the second lowest loss band, usually 1565nm ⁇ 1625nm.
  • the S band is usually 1460nm ⁇ 1530nm.
  • the O band is usually 1260nm ⁇ 1360nm.
  • the E band is usually In the embodiment of the present application, the wavelength of the incident light beam may belong to the wavelength range of 1260nm to 1625nm.
  • Fig. 3 is an enlarged structural schematic diagram of an adjustment unit provided in an embodiment of the present application.
  • the adjustment unit 20a includes a diffraction grating structure.
  • the diffraction grating structure includes a stacked refractive index variable layer 21 and an optical medium layer 22.
  • variable refractive index layer 21 When the adjustment unit 20a is in the first state, the variable refractive index layer 21 has a first refractive index, and when the adjustment unit 20a is in the second state, the variable refractive index layer 21 has a second refractive index, and the first refractive index and the second refractive index are different. That is, under the action of the excitation signal, the refractive index of the variable refractive index layer 21 changes, and the relationship between the refractive index of the variable refractive index layer 21 and the refractive index of the optical medium layer 22 also changes accordingly, so that the state of the adjustment unit 20a switches between the first state and the second state.
  • the refractive index of the optical medium layer 22 matches the first refractive index or the second refractive index.
  • the refractive index of A matches the refractive index of B, which means that the refractive index of A is the same as or close to the refractive index of B.
  • the ratio of the difference between the refractive index of A and the refractive index of B to the refractive index of A is within 10%, such as within 5%.
  • the optical medium layer and the variable refractive index layer when the refractive index of the optical medium layer matches the refractive index of the variable refractive index layer, the optical medium layer and the variable refractive index layer form a reflective diffraction grating; and when the refractive index of the optical medium layer does not match the refractive index of the variable refractive index layer, the optical medium layer and the variable refractive index layer form a transmissive diffraction grating.
  • the optical medium layer and the variable refractive index layer when the refractive index of the optical medium layer matches the refractive index of the variable refractive index layer, the optical medium layer and the variable refractive index layer form a transmissive diffraction grating; and when the refractive index of the optical medium layer does not match the refractive index of the variable refractive index layer, the optical medium layer and the variable refractive index layer form a reflective diffraction grating.
  • the absolute value of the difference between the first refractive index and the second refractive index ranges from 0.5 to 10. This refractive index difference can make the diffraction grating structure switch between the reflective diffraction grating and the transmissive diffraction grating when the refractive index of the variable refractive index layer changes, so that the state of the adjustment unit can change accordingly.
  • the absolute value of the difference between the first refractive index and the second refractive index can be above 0.7, or even above 1.0.
  • the upper limit of the absolute value of the difference between the first refractive index and the second refractive index is limited by the capacity of the material.
  • variable refractive index layer 21 can be made of phase change material (PCM), that is, the variable refractive index layer is made of PCM.
  • PCM phase change material
  • PCM has a crystalline state (crystalline, referred to as C state) and an amorphous state (also known as an amorphous state (amorphous, referred to as A state)).
  • C state crystalline
  • a state amorphous state
  • the PCM is in the C state, it has a first refractive index
  • the PCM is in the A state, it has a second refractive index, and the first refractive index is greater than the second refractive index.
  • each adjustment unit includes a wavelength pixel or a plurality of wavelength pixels arranged in an array, wherein a wavelength pixel can be understood as the minimum resolution for individually adjusting a light beam, and each wavelength pixel corresponds to a minimum wavelength range.
  • each adjustment unit includes one wavelength pixel
  • the total area of the PCM corresponding to each wavelength pixel is 19200 ⁇ m.
  • the response time of the PCM in each pixel wavelength switching from the C state to the A state is about 1 ⁇ s, and the power consumption is about 2.5W; while the response time of the PCM in each pixel wavelength switching from the A state to the C state is about 300ms, and the power consumption is about 0.5W.
  • the PCM in the 2400 wavelength pixels needs to be converted from the C state to the A state, which takes a total of 0.6ms (2400 ⁇ (10W ⁇ 2.5W)*1 ⁇ s. If all 2400 wavelength pixels need to switch from the reflection state to the transmission state, the PCM in the 2400 adjustment units needs to be converted from the A state to the C state, which takes a total of 36s (2400 ⁇ (10W ⁇ 0.5W)*300ms). It can be seen that the speed at which the adjustment unit switches from the transmission state to the reflection state is very fast.
  • PCM has a bistable characteristic
  • energy is consumed only during the switching process between the C state and the A state.
  • no energy is consumed to maintain the state, and it has good thermal stability (that is, it can maintain a steady state under different temperature environments), so it is beneficial to save the power consumption of the optical modulation device.
  • the PCM can adopt any of the following materials: antimony selenide (Sb2Se3), antimony sulfide (Sb2S3), tellurium sulfide (TeS2), germanium antimony telluride (GST, such as Ge2Sb2Te5, etc.), antimony tritelluride (Sb7Te3), germanium tellurium sulfur, germanium arsenic sulfur, germanium antimony selenium (GSSE, such as GeSbSe), germanium tellurium selenium and germanium antimony selenium telluride (GSST, i.e. GeSbSeTe).
  • the PCM is antimony selenide, and when antimony selenide is in the C state, the refractive index is about 4.1. When antimony selenide is in the A state, the refractive index is about 3.3.
  • the material of the optical medium layer is silicon, and the refractive index of silicon is 3.5. When antimony selenide is in the A state, the refractive index matches the refractive index of silicon.
  • the PCM is GSST, and when the GSST is in the C state, the refractive index is about 5.1. When the GSST is in the A state, the refractive index is about 3.4.
  • the material of the optical medium layer is silicon, and the refractive index of silicon is 3.5. When the GSST is in the A state, the refractive index matches the refractive index of silicon.
  • the present application does not impose any restrictions on the type of PCM and the material of the optical medium layer, as long as the refractive index of the PCM matches the refractive index of the optical medium layer when the PCM is in the A state (or C state); and the refractive index of the PCM is significantly different from the refractive index of the optical medium layer when the PCM is in the C state (or A state).
  • the PCM When heated, the PCM changes phase, for example, from state C to state A, or from state A to state C.
  • the optical medium layer When heated, the PCM changes phase, for example, from state C to state A, or from state A to state C.
  • the optical medium layer When heated, the PCM changes phase, for example, from state C to state A, or from state A to state C.
  • the optical medium layer When heated, the PCM changes phase, for example, from state C to state A, or from state A to state C.
  • the optical medium layer generates heat under the action of the electrical signal, thereby causing the phase of the PCM to change.
  • the optical medium layer 22 can be made of transparent conductive materials, such as graphene, ITO, IZO and doped silicon materials.
  • the optical medium layer can be directly used to generate heat under the action of the excitation signal to change the phase state of the phase change material, thereby changing the refractive index of the refractive index variable layer.
  • the optical medium layer not only serves as a part of the diffraction grating structure, but also plays a conductive role, which is conducive to simplifying the structure of the adjustment unit.
  • FIG4 is a schematic diagram of the cross-sectional structure of the adjustment unit shown in FIG3 along the A-A line.
  • the refractive index variable layer 21 includes a plurality of first block structures 211 arranged in an array.
  • the plurality of first block structures 211 are arranged in a one-dimensional array, and the plurality of first block structures 211 are arranged along a first direction.
  • the optical medium layer 22 includes a plurality of second block structures 221 arranged in an array, and the plurality of second block structures 221 are also arranged along the first direction.
  • the arrangement direction of the plurality of first block structures 211 is the same as the arrangement direction of the plurality of adjustment units 20a, for example, both are arranged left and right.
  • the first block structure 211 and the second block structure 221 are both long strip structures.
  • the length directions of the first block structure 211 and the second block structure 221 are consistent, and the length direction of the first block structure 211 is perpendicular to the arrangement direction of the plurality of first block structures 211.
  • the second block structure 221 is connected to the first block structure 211 in a one-to-one correspondence, and the width of the first block structure 211 is equal to the width of the second block structure 221.
  • the first direction is perpendicular to the stacking direction of the variable refractive index layer 21 and the optical medium layer 22.
  • the width refers to the dimension in the first direction.
  • the refractive index of the optical medium layer 22 matches the second refractive index.
  • the refractive index of the first block structure is the first refractive index
  • the refractive index of the first block structure is greater than the refractive index of the second block structure, and the adjustment unit is in a transmission state.
  • the refractive index of the first block structure is the second refractive index
  • the refractive index of the first block structure is substantially equal to the refractive index of the second block structure, and the adjustment unit is in a reflection state.
  • the refractive index of the optical medium layer 22 matches the first refractive index.
  • the refractive index of the first block structure is the first refractive index
  • the refractive index of the first block structure is substantially equal to the refractive index of the second block structure, and the adjustment unit is in a transmission state.
  • the refractive index of the first block structure is the second refractive index
  • the refractive index of the first block structure is less than the refractive index of the second block structure, and the adjustment unit is in a reflection state.
  • the optical medium layer 22 further includes two connecting bars 222, one end of the plurality of second block structures 221 is connected to one connecting bar 222, and the other end of the plurality of second block structures 221 is connected to another connecting bar 222.
  • the first end of the X-1 second block structure 221 and the first end of the X second block structure 221 can be connected through one connecting bar
  • the second end of the X second block structure 221 and the second end of the X+1 second block structure 221 can be connected through another connecting bar. All the second block structures in the same adjustment unit are connected together through the connecting bars to facilitate connection with the electrical signal input terminal (such as VCC and GND in the figure).
  • the optical medium layer 22 is made of a transparent insulating material.
  • the adjustment unit 20a further includes a transparent conductive layer (not shown), which can be located on the surface of the optical medium layer or on the surface of the variable refractive index layer. Under the action of the excitation signal, the transparent conductive layer generates heat, which is transferred to the variable refractive index layer to change the phase state of the phase change material, thereby changing the refractive index of the variable refractive index layer.
  • the transparent insulating material includes, but is not limited to, silicon, titanium dioxide, silicon nitride, silicon carbide, and silicon oxynitride.
  • the transparent insulating material may be a material with good heat transfer performance, so as to quickly transfer the heat generated by the transparent conductive layer to the variable refractive index layer.
  • the optical adjustment layer 20 further includes a substrate 23, and a plurality of adjustment units 20a are arranged in an array on a first surface of the substrate 23.
  • a second surface of the substrate is directly or indirectly connected to the spatial light modulator.
  • the substrate 23 may be made of materials such as silicon or silicon dioxide.
  • the adjustment unit 20a is first manufactured on the substrate 23, and then the substrate 23 is connected to the spatial light modulator 10. This is convenient to manufacture and can avoid adverse effects on the spatial modulator 10 during the manufacturing process of the adjustment unit 20a.
  • the material of the substrate 23 is the same as that of the second block structure 221, for example, both are silicon.
  • the substrate 23 and the second block structure 221 can be an integral structure.
  • the substrate 23 having a protruding structure is obtained by patterning the surface of a silicon wafer, and the protruding structure is the second block structure 221.
  • the material of the substrate 23 can be the same as that of the cover plate in the spatial light modulator 10, such as silicon dioxide, so that reflection of light at the interface between the substrate 23 and the spatial light modulator 10 can be reduced.
  • the substrate 23 may also be made of other transparent materials.
  • variable refractive index layer and the optical medium layer may be directly formed on the surface of the spatial light modulator 10 , that is, the optical adjustment layer does not include the substrate 23 .
  • the optical adjustment layer 20 further includes a covering layer 24, which is filled between the adjacent first block structures 211 and the adjacent second block structures 221 in the adjustment unit 20a and covers the variable refractive index layer 21, and the covering layer 24 is also filled between adjacent adjustment units 20a.
  • the covering layer can protect the variable refractive index layer and the optical medium layer, and the surface of the covering layer is flat, which is convenient for connection with other surfaces.
  • the covering layer 24 is an optional structure.
  • the optical adjustment layer 20 may not include the covering layer 24, and the space between the adjacent first block structures 211 and the adjacent second block structures 221 may be filled with air.
  • the absolute value of the difference between the refractive index of the cover layer 24 and the first refractive index is greater than 0.5 and/or the absolute value of the difference between the refractive index of the cover layer 24 and the second refractive index is greater than 0.5 to form a diffraction grating structure.
  • the material of the cover layer 24 can be silicon dioxide or the like.
  • the optical adjustment layer 20 further includes an anti-reflection film layer 25, which is located on the cover layer 24.
  • the anti-reflection film layer is used to increase the transmittance of the optical communication band (such as C band, L band or S band) to which the incident light beam belongs.
  • the anti-reflection film layer can be a multilayer dielectric material film.
  • the thickness of the variable refractive index layer 21 is greater than 0 and not greater than 150 nm, for example, 20 nm to 30 nm.
  • the thickness of the optical medium layer 22 is not greater than 1.5 ⁇ m.
  • the grating period is less than the wavelength corresponding to the adjustment unit, for example, about 750 nm, and the duty cycle can be 5% to 95%. In some examples, the duty cycle can be 30 to 70%, for example, 50%.
  • the shapes and sizes of the diffraction grating structures in all adjustment units 20a are the same to simplify the manufacturing process of the optical adjustment layer. In other examples, the shapes and/or sizes of the diffraction grating structures in the adjustment units 20a corresponding to different wavelengths are different to improve the control accuracy of the optical adjustment layer.
  • FIG5 is a schematic diagram of a top view of another adjustment unit provided in an embodiment of the present application.
  • FIG6 is a schematic diagram of a cross-sectional structure of the adjustment unit shown in FIG5 along the B-B line.
  • the arrangement direction of the multiple first block structures 211 in the adjustment unit 20a is perpendicular to the arrangement direction of the multiple adjustment units 20a.
  • the arrangement direction of the multiple adjustment units 20a is along the left-right direction, while the arrangement direction of the multiple first block structures 211 in FIG5 is in the up-down direction.
  • the length direction of the first block structure 211 is consistent with the arrangement direction of the multiple adjustment units 20a.
  • the cross-sectional structure of the adjustment unit 20a is the same as that of FIG4 and will not be described in detail here.
  • Fig. 7 is a schematic diagram of a top view of another adjustment unit provided in an embodiment of the present application.
  • Fig. 8 is a schematic diagram of a cross-sectional structure of the adjustment unit along line C-C in Fig. 7.
  • the plurality of first block structures 211 are arranged in a two-dimensional array, i.e., in a matrix arrangement.
  • the first block structure 211 and the second block structure 221 are both columnar structures, and the length direction of the first block structure 221 (i.e., the up-down direction in FIG8 ) is perpendicular to the first arrangement direction and the second arrangement direction of the plurality of first block structures 221, and is parallel to the stacking direction of the variable refractive index layer 21 and the optical medium layer 22.
  • the first arrangement direction and the second arrangement direction are the row direction and the column direction of the matrix, respectively.
  • the hierarchical structure of the adjustment unit 20 a in FIG. 8 removes the anti-reflection film layer 25 , and the other structures are substantially the same as those in FIG. 4 , which will not be described in detail here.
  • the optical medium layer 22 and the refractive index variable layer 21 are stacked in sequence on the substrate 23 as an example.
  • the refractive index variable layer 21 and the optical medium layer 22 can also be stacked in sequence on the substrate 23, as long as it can be ensured that when the refractive index variable layer 21 has different refractive indices, it can cooperate with the optical medium layer 22 to form a reflective diffraction grating and a transmissive diffraction grating respectively.
  • Fig. 9 is a schematic diagram of the structure of another light modulation device provided in an embodiment of the present application.
  • the light modulation device includes a spatial light modulator 10 and an optical adjustment layer 20.
  • the optical adjustment layer 20 is connected to the surface of the spatial light modulator 10.
  • the spatial light modulator 10 is an LCOS modulator, and includes a back plate 11, a first electrode layer 12, a liquid crystal layer 13, a second electrode layer 14 and a transparent cover plate 15 which are stacked in sequence.
  • the backplane 11 includes a plurality of drive circuits arranged in an array (not shown).
  • the first electrode layer 12 includes a plurality of first electrodes 121 (also called pixel electrodes).
  • One modulation unit corresponds to one first electrode 121 or to a plurality of first electrodes 121 arranged in an array.
  • Each first electrode 121 is connected to a drive circuit
  • the second electrode layer 14 includes a plurality of second electrodes, and the plurality of second electrodes are an integrated structure.
  • the second electrode layer 14 is a whole-surface structure.
  • Each drive circuit is used to provide a voltage to the connected first electrode to change the electric field between the first electrode and the second electrode, so that the deflection direction of the liquid crystal molecules changes, thereby changing the effective refractive index of the liquid crystal to change the size of the optical path of the light, thereby achieving the purpose of phase modulation.
  • the first electrode layer 12 and the second electrode layer 13 are both transparent conductive material layers, such as an indium tin oxide (ITO) layer, an indium zinc oxide (IZO) layer, etc.
  • the transparent cover plate 15 is a glass cover plate, a plastic cover plate, etc.
  • the light modulation device further includes a pre-deflection layer 30.
  • the pre-deflection layer 30 is located between the spatial light modulator 10 and the optical adjustment layer 20.
  • the pre-deflection layer 30 is used to deflect the propagation direction of the incident light beam by a set angle.
  • the pre-deflection layer 30 can deflect the incident angles of all incident light beams by the same angle, or deflect the incident angles of the incident light beams by different angles according to the wavelength.
  • FIG10 is a schematic diagram of a top view structure of a pre-deflection layer provided in an embodiment of the present application.
  • the pre-deflection layer 30 includes a plurality of deflection units 30a arranged in an array.
  • the plurality of deflection units 30a correspond one to one with the plurality of adjustment units 20a.
  • the first deflection unit with the first adjustment unit is located on the optical path between the first adjustment unit and the first adjustment unit, and the first deflection unit is used to deflect the light of the first adjustment unit by a set angle and then emit it to the first modulation unit.
  • the set angle is greater than 0° and less than 10°.
  • FIG11 is an enlarged structural schematic diagram of a deflection unit provided in an embodiment of the present application.
  • the deflection unit 30a is a periodic structure, and the arrangement direction of multiple periods 30b in the deflection unit 30a is perpendicular to the arrangement direction of the multiple deflection units 30a.
  • Each period 30b includes a strip structure extending along the arrangement direction of the deflection unit 30a.
  • FIG12 is a schematic diagram of the cross-sectional structure of the deflection unit shown in FIG11.
  • the deflection unit 30a includes a first dielectric layer 31 and a second dielectric layer 32.
  • the refractive index of the first dielectric layer 31 is not equal to the refractive index of the second dielectric layer 32.
  • the refractive index of the first dielectric layer 31 is greater than the refractive index of the second dielectric layer 32, or the refractive index of the first dielectric layer 31 is less than the refractive index of the second dielectric layer 32.
  • the first dielectric layer 31 is a blazed grating.
  • Each wedge-shaped protrusion of the blazed grating is a period in the periodic structure.
  • the material of the first dielectric layer 31 may be silicon, silicon dioxide, silicon nitride, silicon oxynitride, silicon carbide, etc.
  • the material of the second dielectric layer 32 may be silicon, silicon dioxide, silicon nitride, silicon oxynitride, silicon carbide, etc.
  • the first dielectric layer 31 and the second dielectric layer 32 are usually formed of different materials.
  • FIG13 is a schematic diagram of a cross-sectional structure of another deflection unit provided in an embodiment of the present application. As shown in FIG13 , the difference from the deflection unit shown in FIG12 is that the first dielectric layer 31 includes a plurality of strip structures arranged in parallel. The spacing of the plurality of strip structures in each period varies gradually, forming a grating structure with a gradually varying spacing.
  • the grating structure with gradually changing spacing means that the spacing between two adjacent strip structures in the grating is unequal and gradually changes (e.g., linearly changes, etc.). For example, in FIG13 , from top to bottom, the spacing between two adjacent strip structures in each non-equally spaced grating gradually decreases.
  • the multiple strip structures in each period can also form a non-equal duty cycle grating structure.
  • the non-equal duty cycle grating structure means that the ratio of the width of the strip structure in the grating to the grating period is not equal.
  • FIG14 is a schematic diagram of a cross-sectional structure of a deflection unit provided in an embodiment of the present application.
  • the difference from the deflection unit shown in FIG12 is that the first dielectric layer 31 includes a plurality of DOEs, and the arrangement direction of the plurality of DOEs is perpendicular to the arrangement direction of the plurality of deflection units 30a.
  • Each DOE is a multi-layer step structure.
  • Each DOE is a period in the periodic structure.
  • Figure 14 the number of steps of each DOE increases gradually from top to bottom.
  • Figure 14 shows four steps as an example, but the embodiment of the present application does not limit the number of steps and can be set as needed.
  • the first dielectric layer 31 in each deflection unit 30a has the same morphology, and when dispersion is ignored, light beams of all wavelengths can be deflected at the same angle.
  • the first dielectric layer 31 in different deflection units 30a has morphologies corresponding to wavelengths, and different wavelengths have different morphologies, so that light beams of different wavelengths can be deflected at different angles.
  • FIG15 is a schematic diagram of the propagation path of light in the optical modulation device shown in FIG9 when the optical adjustment layer is in the first state.
  • the first light beam B1 is incident on the first adjustment unit of the optical adjustment layer 20.
  • the optical adjustment layer 20 is in a transmission state, and transmits the first light beam B1 to the pre-deflection layer 30.
  • the pre-deflection layer 30 deflects the first light beam B1 by a certain angle and then emits it to the spatial light modulator 10.
  • the spatial light modulator 10 performs phase modulation on the first light beam B1 and then reflects it.
  • the reflected light beam corresponding to the first light beam B1 passes through the pre-deflection layer 30 and the optical adjustment layer 20 in sequence and then emits it to the first direction P1.
  • the second light beam B2 is incident on the first adjustment unit of the optical adjustment layer 20, and the optical adjustment layer 20 is in a transmission state, transmitting the second light beam B2 to the pre-deflection layer 30.
  • the pre-deflection layer 30 deflects the second light beam B2 by a certain angle and then emits it to the spatial light modulator 10.
  • the spatial light modulator 10 performs phase modulation on the second light beam B2 and then reflects it.
  • the reflected light beam corresponding to the second light beam B2 passes through the pre-deflection layer 30 again and is deflected by the same angle, and then passes through the optical adjustment layer 20 and emits to the second direction P2.
  • FIG. 15 shows the propagation directions of the first light beam B1 and the second light beam B2 after being deflected by the same angle to reach the space.
  • the light modulator 10 for example, is deflected to the left by a certain angle before reaching the spatial light modulator.
  • the first light beam B1 and the second light beam B2 emitted by the spatial light modulator 10 are also deflected to the left by the same angle before being emitted through the optical adjustment layer 20 .
  • FIG16 is a schematic diagram of the propagation path of light of the light modulation device shown in FIG10 when the optical adjustment layer is in the second state. As shown in FIG16 , the second light beam B2 is incident on the first adjustment unit of the optical adjustment layer 20. The first adjustment unit is in a reflective state, and the first adjustment unit reflects the first light beam B1 to the first direction P1.
  • Fig. 17 is a schematic diagram of the structure of another optical modulation device provided in an embodiment of the present application.
  • the pre-deflection layer is located between the transparent cover plate 15 and the second electrode layer 14.
  • the transparent cover plate is a double-layer structure, and the pre-deflection layer can be sandwiched between the two cover plates.
  • the turning prism 40 is a right-angle prism
  • the first surface is a right-angle surface of the right-angle prism
  • the second surface is an inclined surface of the right-angle prism
  • the third surface is another right-angle surface of the right-angle prism.
  • the first state is a reflective state
  • the second state is a transmissive state
  • the reflective element 50 is integrated with the pre-deflection layer 30.
  • the reflective element 50 is a reflective layer located on a surface of the pre-deflection layer 30 that is away from the optical conditioning layer 20.
  • FIG19 is a schematic diagram of a cross-sectional structure of a deflection unit of the pre-deflection layer in FIG18.
  • the deflection unit 30a includes a first dielectric layer 31 and a reflective layer.
  • the first dielectric layer 31 has the morphology of a blazed grating. That is, the surface of the first dielectric layer 31 has a plurality of long strip ridges, and the length direction of each long strip ridge is parallel to the arrangement direction of the plurality of deflection units 30a.
  • Each long strip ridge includes a first surface and a second surface connected. The first surfaces of the plurality of long strip ridges are parallel to each other, and the second surfaces of the plurality of long strip ridges are parallel to each other.
  • the reflective layer covers the second surface.
  • the first dielectric layer 31 can be a silicon dioxide layer, a silicon layer, a silicon nitride layer, a silicon oxynitride layer, and a silicon carbide layer.
  • the reflective layer 50 is a metal layer, especially a metal layer with high reflectivity in the optical communication band (eg, 1550 nm band), such as an Al layer, an Ag layer, and an Au layer.
  • FIG20 is a schematic diagram of the propagation path of light of the optical modulation device shown in FIG18 when the optical adjustment layer is in the first state.
  • the turning prism 40 is located on the incident light path of the first light beam B1 and the second light beam B2, and the first light beam B1 and the second light beam B2 are incident on the optical adjustment layer 20 through the turning prism 40.
  • Each adjustment unit in the optical adjustment layer 20 is in a reflective state, and the optical adjustment layer 20 reflects the first light beam B1 to the spatial light modulator 10.
  • the spatial light modulator 10 deflects the first light beam B1 at an angle and emits it to the optical adjustment layer 20, and after being reflected by the optical adjustment layer 20, it emits it along the first direction P1.
  • the spatial light modulator 10 deflects the second light beam B2 at an angle and emits it to the optical adjustment layer 20, and after being reflected by the optical adjustment layer 20, it emits it along the second direction P2.
  • FIG21 is a schematic diagram of the propagation path of light in the light modulation device shown in FIG18 when the optical adjustment layer is in the second state.
  • the second light beam B2 is incident on the optical adjustment layer 20 through the turning prism 40.
  • the corresponding adjustment unit in the optical adjustment layer 20 is in the transmission state, and the optical adjustment layer 20 transmits the second light beam B2 to the pre-deflection layer 30.
  • the second light beam B2 After being deflected by the pre-deflection layer 30 and reflected by the reflective element 50, the second light beam B2 is emitted along the first direction P1.
  • FIG22 is a schematic diagram of the structure of another optical modulation device provided in an embodiment of the present application.
  • the structure of the optical modulation device is basically the same as that of the optical modulation device in FIG18, except that the optical modulation device in FIG22 further includes another turning prism 60.
  • One surface of the other turning prism 60 is connected to the optical adjustment layer 20, and the other surface of the other turning prism 60 is connected to the pre-deflection layer 30. And the surface where the pre-deflection layer 30 is located is opposite to the incident surface.
  • FIG23 is another schematic diagram of a cross-sectional structure of a deflection unit of the pre-deflection layer in FIG22.
  • the deflection unit 30a includes a first dielectric layer 31 and a reflective layer 50.
  • the first dielectric layer 31 has a first surface and a second surface, the first surface is a plane and connected to the surface of the other turning prism 60, and the second surface is at an angle to the first surface.
  • the reflective layer 50 is located on the second surface.
  • FIG24 is a schematic diagram of the propagation path of light in the light modulation device in FIG22 when the optical adjustment layer is in the first state.
  • the first light beam B1 and the second light beam B2 are incident on the optical adjustment layer 20 through the turning prism 40.
  • Each adjustment unit in the optical adjustment layer 20 is in a reflective state, and the optical adjustment layer 20 reflects the first light beam B1 and the second light beam B2 to the spatial light modulator 10.
  • the spatial light modulator 10 deflects the first light beam B1 at an angle and emits it to the optical adjustment layer 20, and after being reflected by the optical adjustment layer 20, it emits it along the first direction P1.
  • the spatial light modulator 10 deflects the second light beam B2 at an angle and emits the second light beam B2 to the optical adjustment layer 20 .
  • the second light beam B2 is reflected by the optical adjustment layer 20 and then emitted along the second direction P2 .
  • FIG25 is a schematic diagram of the propagation path of light in the optical modulation device shown in FIG22 when the optical adjustment layer is in the second state.
  • the second light beam B2 is incident on the optical adjustment layer 20 through the turning prism 40.
  • the corresponding adjustment unit in the optical adjustment layer 20 is in the transmission state, and the optical adjustment layer 20 transmits the second light beam B2 to the pre-deflection layer 30.
  • the second light beam B2 After being deflected by the pre-deflection layer 30 and reflected by the reflective element 50, the second light beam B2 is emitted along the first direction P1.
  • FIG26 is a schematic diagram of the structure of another optical modulation device provided in an embodiment of the present application.
  • the optical modulation device further includes a polarization beam splitter 70 and a reflective wave plate 80.
  • the polarization beam splitter 70 is located at the incident surface of the turning prism 40, that is, located on the incident light path of the second light beam B2.
  • the polarization beam splitter 70 is connected to the spatial light modulator 10.
  • the reflective wave plate 80 is located on the surface of the polarization beam splitter 70 opposite to the surface where the spatial light modulator 10 is located.
  • FIG27 is a schematic diagram of the propagation path of light in the light modulation device in FIG26 when the optical adjustment layer is in the first state.
  • the polarization beam splitter 70 is used to transmit the second light beam B2 to the optical adjustment layer 20.
  • the second light beam B2 is a linearly polarized light having a first polarization direction, which can directly pass through the polarization beam splitter 70 and enter the optical adjustment layer 20 after passing through the turning prism 40.
  • the polarization beam splitter 70 is also used to split the fourth light beam into a first light beam B1 and a third light beam B3, wherein the first light beam B1 is a linearly polarized light having a first polarization direction, and the third light beam B3 is a linearly polarized light having a second polarization direction; the first light beam B1 is emitted toward the optical adjustment layer 20, and the third light beam B3 is emitted toward the reflective wave plate 80, and the reflective wave plate 80 is used to convert the third light beam B3 into a linearly polarized light having a first polarization direction and then emit it toward the spatial light modulator 10, and the spatial light modulator 10 is also used to emit the third light beam B3 along the first direction.
  • the propagation paths of the first light beam B1 and the second light beam B2 after reaching the spatial light modulator 10 are shown in FIG. 24.
  • the fourth light beam may be a signal light after long-distance optical fiber transmission. After long-distance optical fiber transmission, the polarization state of the signal light will change randomly.
  • the fourth light beam is firstly divided into linear polarized light with different polarization directions by a polarization beam splitter, and the linear polarized light with a first polarization direction is directly emitted to the spatial light modulator, and the linear polarized light with a second polarization direction is converted into linear polarized light with the first polarization direction by a reflective wave plate and then emitted to the spatial light modulator, so that the fourth light beam can be polarization multiplexed to simplify the optical design.
  • the first polarization direction is perpendicular to the second polarization direction, for example, the linear polarization light in the first polarization direction is P light, and the linear polarization light in the second polarization direction is S light.
  • the reflective wave plate is a 1/4 wave plate.
  • FIG28 is a schematic diagram of the propagation path of light in the light modulation device shown in FIG26 when the optical adjustment layer is in the second state.
  • the second light beam B2 is incident on the optical adjustment layer 20.
  • the corresponding adjustment unit in the optical adjustment layer 20 is in the transmission state, and the optical adjustment layer 20 transmits the second light beam B2 to the pre-deflection layer 30.
  • the second light beam B2 After being deflected by the pre-deflection layer 30 and reflected by the reflective element 50, the second light beam B2 is emitted along the first direction P1.
  • the optical modulation device provided in the embodiment of the present application does not include mechanical structures and organic materials, and the device life and reliability are high.
  • the optical modulation device can be integrated in the WSS, with low insertion loss, simple structure and low cost.
  • the structure of the WSS integrated with the optical modulation device is described in detail below.
  • FIG. 29 is a schematic diagram of the structure of a WSS provided in the embodiment of the present application.
  • FIG. 30 is a side view of FIG. 29.
  • the WSS includes an interface unit 1, a wave splitting unit 2 and an optical modulation device 3.
  • the optical modulation device 3 is any one of the aforementioned modulation devices.
  • the interface unit 1 includes M input ports and N output ports, which are arranged in an array, wherein M and N are integers, and at least one of M and N is greater than 1.
  • Each port is connected to an optical fiber.
  • the optical signal propagated in each optical fiber adopts wavelength division multiplexing, that is, each optical fiber supports optical channels of multiple wavelengths. The wavelengths of the signal light transmitted in different input ports may be different.
  • the interface unit 1 includes M input ports and 1 output port, and the M input ports and 1 output port are arranged side by side.
  • the arrangement direction of each port in the interface unit 1 is perpendicular to the aforementioned wavelength arrangement direction.
  • the interface unit 1 includes 3 input ports (respectively ports IN0 to IN2) and 1 output port (port OUT).
  • the arrangement direction of the ports is parallel to the up-and-down direction of the paper, while the wavelength arrangement direction is perpendicular to the paper.
  • the splitter unit 2 includes a splitter device 2a and an optical path adjustment device 2b.
  • the splitter device 2a is used to split the light input from each input port according to the wavelength, and guide the light beams of each wavelength obtained after the splitting to the optical path adjustment device 2b.
  • the optical path adjustment device 2b is used to guide the light beams of each wavelength to the adjustment unit corresponding to the wavelength in the optical modulation device 3.
  • the wave splitting device 2a may include a diffraction grating, etc.
  • the optical path adjusting device 2b may include a spherical mirror, etc.
  • the light modulation device in FIG. 29 and FIG. 30 is illustrated by taking the structure shown in FIG. 1 as an example. In other embodiments, any of the aforementioned light modulation devices may also be used.
  • input ports IN1 and IN2 of the three input ports are connected to a node respectively; input port IN0 is connected to a false light source.
  • the wavelengths of the signal light transmitted in input port IN1 are ⁇ 1 and ⁇ 3, and the wavelength of the signal light transmitted in input port IN2 is ⁇ 2.
  • each adjustment unit of the optical adjustment layer 20 When the WSS is in a normal working state, each adjustment unit of the optical adjustment layer 20 is in a transmission state.
  • the combined signal reaches the demultiplexer unit 2 through the input port in the interface unit 1.
  • the demultiplexer device 2a in the demultiplexer unit 2 demultiplexes the combined signal from each input port according to the wavelength, and transmits the light of each wavelength to the corresponding adjustment unit in the optical modulation device 3 through the optical path adjustment device 2b. Since the adjustment unit is in a transmission state, the light of each wavelength passes through the optical adjustment layer and is further transmitted to the spatial light modulator.
  • Each modulation unit of the spatial light modulator controls the arrangement of liquid crystal molecules to form a specific phase-type diffraction grating, thereby deflecting and reflecting the light beam of the corresponding wavelength.
  • the reflected light beam returns to the optical path adjustment device 2b of the demultiplexer unit 2, and the angle deflection is converted into position movement.
  • the demultiplexer device 2a After passing through the optical path adjustment device 2b, the demultiplexer device 2a combines the light beams of each wavelength, and outputs the combined light beam from the output port OUT.
  • the false light with wavelengths of ⁇ 1, ⁇ 2 and ⁇ 3 input by the input port IN0 is output to the non-port position.
  • the output port OUT corresponds to the aforementioned first direction
  • the non-port position corresponds to the aforementioned second direction.
  • dummy light of different wavelengths can be emitted to different non-port positions.
  • dummy light of wavelengths ⁇ 1 and ⁇ 3 is emitted to non-port position X1
  • dummy light of wavelength ⁇ 2 is emitted to non-port position X2.
  • FIG31 is a schematic diagram of another working state of the WSS shown in FIG29.
  • FIG32 is a side view of FIG31.
  • This working state of the WSS can be referred to as a false light filling state.
  • the adjustment unit corresponding to the wavelength ⁇ 2 in the optical adjustment layer 20 is controlled to switch from the transmission state to the reflection state, and the false light with a wavelength of ⁇ 2 is reflected to the demultiplexing unit 2 by the corresponding adjustment unit.
  • the other adjustment units in the optical adjustment layer 20 still maintain the transmission state, so the propagation path of the signal light with wavelengths of ⁇ 1 and ⁇ 3 input into the input port IN1 and the propagation path of the false light with wavelengths of ⁇ 1 and ⁇ 3 input from the input port IN0 are the same as those in FIG29.
  • the wavelength splitting unit 2 outputs the false light with wavelength ⁇ 2 together with the light with wavelengths ⁇ 1 and ⁇ 3 from the output port OUT, so that the output port OUT still maintains the full-wave state of wavelengths ⁇ 1, ⁇ 2 and ⁇ 3, suppresses stimulated Raman scattering (SRS) and the corresponding hole burning effect, and maintains the power stability of the optical signals of each wavelength.
  • SRS stimulated Raman scattering
  • the input port IN0, input port IN1, input port IN2 and output port OUT are arranged symmetrically about the main optical axis.
  • the optical modulation device does not include a pre-deflection layer and the optical adjustment layer is in a reflective state, the 0th order diffraction light of the false light will directly enter the output port OUT, and the port isolation is poor.
  • the pre-deflection layer can pre-deflect the light beam reaching the spatial light modulator so that the 0th order diffraction light of the false light is no longer directly incident on the output port OUT, thereby improving the port isolation of the WSS.
  • FIG33 is a schematic diagram of the structure of an optical communication device provided in the embodiment of the present application.
  • the optical communication device 300 includes a false light source 301 and a WSS 302.
  • the false light source 301 is connected to the first input port of the WSS 302.
  • the dummy light source 301 is used to emit dummy light, which is usually an unmodulated optical signal.
  • the dummy light provides a wide-spectrum optical signal, and the wavelength range of the dummy light at least partially overlaps with the working wavelength range of the WSS.
  • the wavelength range of the dummy light at least includes the wavelength of the aforementioned second light beam.
  • the wavelength range of the dummy light includes the working wavelength range of the WSS. In this way, no matter which wavelength of the signal light is dropped, the dummy light filling can be achieved.
  • the optical communication equipment includes a reconfigurable optical add-drop multiplexer (ROADM), an optical cross connect (OXC) or other types of optical switching/optical scheduling equipment.
  • ROADM reconfigurable optical add-drop multiplexer
  • OXC optical cross connect
  • FIG34 is a schematic diagram of the structure of another optical communication device provided in an embodiment of the present application.
  • the optical communication device 300 includes a false light source 301, a WSS 302, a local wave module 303 and an optical amplifier 304.
  • An input port of the WSS 302 is connected to the false light source 301.
  • the other input ports of the WSS 302 are respectively connected to other nodes and the local wave module 303.
  • the output port of the WSS 302 is connected to the input port of the optical amplifier 304, and the output port of the optical amplifier 304 is connected to the optical fiber.
  • the optical communication device 300 and other nodes together form a forward transmission network.
  • the optical signal from node 1 is lost.
  • the corresponding wavelength signal of optical amplifier 304 is suddenly missing. Due to the existence of SRS effect, it will cause power fluctuation of other wavelength signals, causing signal damage.
  • the dummy light of the corresponding wavelength provided by the dummy light source 301 is used to fill the lost optical signal to avoid signal damage.
  • the optical signal of each input port of the WSS can be monitored by an optical power detection device so as to timely detect the optical signal drop situation.
  • dotted lines are used in the figure to represent the second light beam and the false light, and real lines are used to represent the first light beam and the signal light.

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)

Abstract

一种光调制装置、WSS和光通信设备，属于光调制技术领域。光调制装置包括空间光调制器和光学调节层；空间光调制器包括阵列布置的多个调制单元；光学调节层包括阵列布置的多个调节单元；多个调节单元中的第一调节单元被配置为在激励信号作用下在第一状态和第二状态之间切换；第一调节单元用于在第一状态下将接收到的第一光束导向第一调制单元，第一调制单元用于对第一光束进行调制，以及将调制后的第一光束沿第一方向出射；或者，第一调节单元用于在第二状态下，将接收到的第二光束沿该第一方向出射。第二光束与第一光束波长相同，且第二光束与第一光束入射至第一调节单元的入射角不同。

Description

光调制装置、波长选择开关和光通信设备
本申请要求于2022年09月27日提交的申请号为202211183240.0、发明名称为“光调制装置、波长选择开关和光通信设备”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及光调制技术领域，特别涉及一种光调制装置、波长选择开关(wavelength selective switch，WSS)和光通信设备。
背景技术
空间光调制技术是一种能够对光的空间分布进行调制的技术，通常采用光调制装置实现。在外部信号的控制下，光调制装置能够改变空间上光分布的振幅(或强度)、相位或者偏振态等。
相关技术中，光调制装置通常包括空间光调制器。空间光调制器包括阵列布置的多个调制单元，每个调制单元均可以在外部信号的控制下对接收到光束进行调制。当波长相同的第一光束和第二光束以不同的入射角同时入射至同一个调制单元时，调制后的第一光束和第二光束会向不同的方向出射。
该光调制装置可以通过改变调制单元的调制相关参数，来控制调制后的第一光束和第二光束的出射方向，控制方式比较单一。
发明内容
本申请提供了一种光调制装置、WSS和光通信设备，能够增加光束的出射方向的控制方式。
一方面，本申请提供了一种光调制装置。光调制装置包括空间光调制器和光学调节层。所述空间光调制器包括阵列布置的多个调制单元。所述光学调节层包括阵列布置的多个调节单元，所述多个调节单元分别与所述多个调制单元中的一个调制单元对应。所述多个调节单元中的第一调节单元被配置为在激励信号作用下在第一状态和第二状态之间切换，所述第一调节单元为所述多个调节单元中的任一个。所述第一调节单元用于在所述第一状态下，将接收到的第一光束导向第一调制单元，所述第一调制单元为所述多个调制单元中与所述第一调节单元对应的调制单元。所述第一调制单元用于对来自所述第一调节单元的所述第一光束进行调制，以及将调制后的第一光束沿第一方向出射；或者，所述第一调节单元用于在所述第二状态下，将接收到的第二光束沿所述第一方向出射。其中，所述第二光束的波长与所述第一光束的波长相同，且所述第二光束入射至所述第一调节单元的入射角与所述第一光束入射至所述第一调节单元的入射角不同。
在第一调制单元的调制相关参数不变的情况下，通过控制第一调制单元对应的第一调节单元的状态，将波长相同但入射角度不同的第一光束和第二光束中的一个沿第一方向出射。这样，可以根据需要灵活地控制第一光束或第二光束沿第一方向出射。本申请提供的光调制装置除了通过控制第一调制单元的调制相关参数来控制光束的出射方向之外，还可以通过控制第一调节单元的状态来控制光束的出射方向，增加了光束的出射方向的控制方式。
在一些示例中，所述第一调节单元还用于在所述第一状态下，将接收到的第二光束导向所述第一调制单元。所述第一调制单元还用于对来自所述第一调节单元的所述第二光束进行调制，以及将调制后的第二光束沿第二方向出射。由于第一光束和第二光束的波长相同，因此，在相同的调制相关参数下，调制后的第一光束和调制后的第二光束的偏转角度相同，但是由于第一光束和第二光束的入射角不同，所以调制后的第一光束和调制后的第二光束的出射方向不同。
当第一调节单元处于第一状态时，如果第二光束入射至光调制装置，该第二光束会被从不同于第一方向的第二方向出射，避免影响沿第一方向出射的第一光束。因此，光调制装置可以在第二光束始终入射的情况下工作，以便在需要将第二光束出射至第一方向时快速将第二光束切换至从第一方向出射。避免在需要将第二光束出射至第一方向时，再将第二光束入射到光调制装置而导致等待时间过长。
在一些示例中，第一状态为透射状态，第二状态为反射状态。在另一些示例中，第一状态为反射状态， 第二状态为透射状态。在本申请中，透射状态和反射状态是相对的，透射状态下第一调节单元的透过率高于反射状态下第一调节单元的透过率，且透射状态下第一调节单元的反射率高于反射状态下第一调节单元的反射率。考虑到光效，透射状态下的透过率越接近100％越好，而反射状态下的反射率越接近100％越好。
在一些示例中，所述第一调节单元包括衍射光栅结构，所述衍射光栅结构包括层叠在所述空间光调制器上的折射率可变层和光介质层。所述折射率可变层被配置为当所述第一调节单元在所述第一状态时具有第一折射率，当所述第一调节单元在所述第二状态时具有第二折射率，所述第一折射率和所述第二折射率不同。所述光介质层的折射率与所述第一折射率或者所述第二折射率匹配。
折射率可变层包括阵列布置的多个第一块状结构，所述光介质层包括阵列布置的多个第二块状结构，所述第二块状结构与所述第一块状结构一一对应连接。
在一些示例中，当所述光介质层的折射率与所述折射率可变层的折射率相匹配时，所述光介质层和所述折射率可变层形成反射式衍射光栅；而当所述光介质层的折射率与所述折射率可变层的折射率不匹配时，所述光介质层和所述折射率可变层形成透射式衍射光栅。
在另一些示例中，当所述光介质层的折射率与所述折射率可变层的折射率相匹配时，所述光介质层和所述折射率可变层形成透射式衍射光栅；而当所述光介质层的折射率与所述折射率可变层的折射率不匹配时，所述光介质层和所述折射率可变层形成反射式衍射光栅。
在一些示例中，第一折射率和第二折射率的差值在0.5以上。该折射率差值可以使得衍射光栅结构在反射式衍射光栅和透射式衍射光栅之间切换，从而使得第一调节单元在第一状态和第二状态之间切换。
在一些示例中，光介质层和所述折射率可变层形成为一维光栅结构。这种情况下，所述多个第一块状结构一维阵列布置，所述第一块状结构和所述第二块状结构均为长条形结构，所述第一块状结构的长度方向与所述多个第一块状结构的排列方向垂直，且与所述折射率可变层和所述光介质层的层叠方向垂直。
在另一些示例中，光介质层和所述折射率可变层形成为二维光栅结构。这种情况下，所述多个第一块状结构二维阵列布置，所述第一块状结构和所述第二块状结构均为柱状结构，所述第一块状结构的长度方向与所述多个第一块状结构的任一排列方向垂直，且与所述折射率可变层和所述光介质层的层叠方向平行。
在一些示例中，所述折射率可变层采用相变材料形成，相变材料的相态变化引起折射率可变层的折射率变化。可选地，所述相变材料选自以下材料中的任一种：硒化锑、硫化锑、硫化碲、锗锑碲、三碲化七锑、锗碲硫、锗砷硫、锗碲硒和锗锑硒碲。相变材料的相态变化的速度快，有利于实现调节单元的工作状态(即前述第一状态和第二状态)的快速切换。
在一种可能的实施方式中，所述光介质层采用透明导电材料制成。当光介质层采用透明导电材料时，在激励信号作用下，光介质层产生热量，使得相变材料的相态变化，从而使得折射率可变层的折射率变化。这种实施方式中，光介质层即作为衍射光栅结构的一部分，又起到导电的作用，有利于简化调节单元的结构。
在该实施方式中，光介质层可以采用石墨烯、氧化铟锡或者掺杂的硅等材料制成。
在另一种可能的实施方式中，所述光介质层采用透明绝缘材料制成。所述调节单元还包括透明导电层，所述透明导电层位于所述光介质层的表面或者位于所述折射率可变层的表面。透明导电层在激励信号作用下，产生热量，热量传导至折射率可变层使得相变材料的相态变化，从而使得折射率可变层的折射率变化。
在该实施方式中，所述光介质层可以采用以下任一种材料制成：硅、二氧化钛、氮化硅、碳化硅和氮氧化硅。
可选地，所述光学调节层还包括基底，所述多个调节单元阵列布置在所述基底的第一表面。该基底的第二表面与空间光调制器直接或者间接连接。先在基底上制作调节单元，然后再将基底与空间光调制器连接，制作方便，并且可以避免在调节单元的制作过程中，对空间调制器产生不良影响。
可选地，所述光学调节层还包括覆盖层，所述覆盖层填充于任意相邻的两个所述第一块状结构和任意相邻的两个所述第二块状结构之间且覆盖所述折射率可变层。该覆盖层可以起到保护折射率可变层和光介质层的作用，并且，覆盖层的表面平坦，便于与其他表面连接。
可选地，所述光学调节层还包括增透膜层，所述增透膜层位于所述覆盖层上。该增透膜层用于提高入射光束所属光通信波段(例如C波段、L波段或者S波段)的透射率。
在一种可能的实施方式中，所述第一状态为透射状态，所述第二状态为反射状态。所述光学调节层与所述空间光调制器的表面连接。
在另一种可能的实施方式中，所述第一状态为反射状态，所述第二状态为透射状态。所述光调制装置还包括转折棱镜和反射元件，所述转折棱镜位于所述第一光束和所述第二光束的入射光路上。所述转折棱镜的第一表面与所述空间光调制器的表面连接，所述转折棱镜的第二表面与所述光学调节层连接，所述反射元件和所述空间光调制器分别位于所述光学调节层的两侧。
示例性地，转折棱镜为直角棱镜，转折棱镜的第一表面为一个直角面，转折棱镜的第二表面为斜面。
可选地，所述光调制装置还包括：偏振分束器和反射式波片。所述偏振分束器位于所述第二光束的入射光路上，所述偏振分束器用于将所述第二光束透射至所述光学调节层。其中，所述第一光束为具有第一偏振方向的线偏振光。所述偏振分束器还用于将第四光束分为所述第一光束和第三光束，所述第一光束为具有所述第一偏振方向的线偏振光，所述第三光束为具有第二偏振方向的线偏振光；将所述第一光束向所述光学调节层出射，将所述第三光束向所述反射式波片出射，所述反射式波片用于将所述第三光束转换为具有所述第一偏振方向的线偏振光后向所述空间光调制器出射。
由于光信号经过光纤长距离传输后，偏振态会发生随机变化，因此，当第四光束为经过光纤长距离传输后的光信号时，先通过偏振分束器将第四光束分为偏振方向不同的线偏振光，将具有第一偏振方向的线偏振光直接向空间光调制器出射，并利用反射式波片将具有第二偏振方向的线偏振光转换为具有所述第一偏振方向的线偏振光后向所述空间光调制器出射，能够对第四光束进行偏振复用处理，简化光学设计。
可选地，所述空间光调制装置还包括预偏转层，所述预偏转层包括阵列布置的多个偏转单元，所述多个偏转单元与所述多个调节单元一一对应。所述多个偏转单元中与所述第一调节单元的第一偏转单元位于所述第一调节单元和所述第一调制单元之间的光路上，所述第一偏转单元用于将所述第一调节单元的光偏转设定角度后出射至所述第一调制单元。
示例性地，所述多个偏转单元中的任一偏转单元包括闪耀光栅、衍射光学元件(diffraction of element，DOE)、间距渐变的光栅结构或者占空比渐变的光栅结构。
可选地，所述空间光调制器为硅基液晶(liquid crystal on silicon，LCOS)调制器和微机电系统(micro-electro-mechanical system，MEMS)调制器和液晶(liquid crystal，LC)调制器中的任一种。
另一方面，本申请提供了一种WSS，所述波长选择开关包括接口单元、分波单元和光调制装置。所述接口单元包括M个输入端口和N个输出端口，所述M个输入端口和所述N个输出端口阵列布置，其中，M和N均为整数，且M和N中的至少一个大于1。所述光调制装置为前述任一种光调制装置。所述分波单元用于将来自所述M个输入端口的光束进行分波，得到多个波长的光束，以及将不同波长的光束输出至所述光调制装置的不同调节单元；将所述光调制装置沿所述第一方向出射的光束输出至所述N个输出端口中的一个。
可选地，所述分波单元还用于将所述光调制装置沿所述第二方向出射的光束输出至所述N个输出端口之外的位置，使得光调制装置沿所述第二方向出射的光束不能从WSS出射。
又一方面，本申请提供了一种光通信设备。所述光通信设备包括假光光源和前述任一种WSS，所述假光光源与所述WSS的第一输入端口连接，所述假光光源用于提供假光，所述假光的波长范围与所述波长选择开关的工作波长范围至少部分重叠，所述第二光束为所述假光的一部分。
在一些示例中，所述假光的波长范围包括WSS的工作波长范围。这样，当与WSS连接的任一输入端口掉波时，均能够采用假光光源提供的对应波长的假光进行填充。
附图说明
图1是本申请实施例提供的一种光调制装置的结构示意图；
图2是本申请实施例提供的一种光学调节层的俯视结构示意图；
图3是本申请实施例提供的一种调节单元的放大结构示意图；
图4是图3所示调节单元的一种截面结构示意图；
图5是本申请实施例提供的另一种调节单元的放大结构示意图；
图6是图5所示的调节单元的一种截面结构示意图；
图7是本申请实施例提供的又一种调节单元的放大结构示意图；
图8是图7所示的调节单元的一种截面结构示意图；
图9是本申请实施例提供的另一种光调制装置的结构示意图；
图10是本申请实施例提供的一种预偏转层的俯视结构示意图；
图11是本申请实施例提供的一种偏转单元的放大结构示意图；
图12是本申请实施例提供的一种偏转单元的截面结构示意图；
图13是本申请实施例提供的另一种偏转单元的截面结构示意图；
图14是本申请实施例提供的又一种偏转单元的截面结构示意图；
图15是图9所示的光调制装置在第一状态下的工作过程示意图；
图16是图9所示的光调制装置在第二状态下的工作过程示意图；
图17是本申请实施例提供的又一种光调制装置的结构示意图；
图18是本申请实施例提供的又一种光调制装置的结构示意图；
图19是本申请实施例提供的又一种偏转单元的截面结构示意图；
图20是图18所示的光调制装置在第一状态下的工作过程示意图；
图21是图18所示的光调制装置在第二状态下的工作过程示意图；
图22是本申请实施例提供的又一种光调制装置的结构示意图；
图23是本申请实施例提供的又一种偏转单元的截面结构示意图；
图24是图22所示的光调制装置在第一状态下的工作过程示意图；
图25是图22所示的光调制装置在第二状态下的工作过程示意图；
图26是本申请实施例提供的再一种光调制装置的结构示意图；
图27是图26所示的光调制装置在第一状态下的工作过程示意图；
图28是图26所示的光调制装置在第二状态下的工作过程示意图；
图29是本申请实施例提供的WSS在一种工作状态下的示意图；
图30是图29的侧视图；
图31是本申请实施例提供的WSS在另一种工作状态下的示意图；
图32是图31的侧视图；
图33是本申请实施例提供的又一种光通信设备的结构示意图；
图34是本申请实施例提供的又一种光通信设备的结构示意图。
具体实施方式
本申请实施例提供了一种光调制装置，通过将光学调节层与空间光调制器结合，改变光学调节层的状态，灵活控制光束的出射位置。
图1是本申请实施例提供的一种光调制装置的结构示意图。如图1所示，该光调制装置包括：空间光调制器10和光学调节层20。
空间光调制器10包括阵列布置的多个调制单元10a。可选地，空间光调制器10中的多个调制单元10a可以一维阵列布置，例如排成一行多列，或者一列多行；或者，空间光调制器10中的多个调制单元10a可以二维阵列布置，例如排列成多行多列。
光学调节层20包括阵列布置的多个调节单元20a。多个调节单元20a与多个调制单元10a一一对应。即多个调节单元20a的排列方式与多个调制单元10a的排列方式相同，且每个调节单元20a对应一个调制单元10a。
每个调节单元20a均被配置为在激励信号作用下在第一状态和第二状态之间切换。示例性地，激励信号包括但不限于电信号或者热信号等。
以第一调节单元为例，第一调节单元为光学调节层中的任一调节单元。第一调节单元用于在第一状态下，将接收到的第一光束B1导向第一调制单元，第一调制单元为多个调节单元中与第一调节单元对应的调制单元。第一调制单元用于对来自对应的第一调节单元的第一光束B1进行调制，以及将调制后的第一光束B1沿第一方向P1出射。或者，第一调节单元用于在第二状态下，将接收到的第二光束B2沿第一方向P1出射。其中，第二光束B2的波长与第一光束B1的波长相同，且第二光束B2入射至第一调节单元的入射角α2与第一光束B1入射至第一调节单元的入射角α1不同。
在图1所示实施例中，第一状态为透射状态，第一调节单元将第一光束B1透射至第一调制单元；第 二状态为反射状态，第一调节单元将第二光束B2沿第一方向反射出去。
在第一调制单元的调制相关参数不变的情况下，通过控制第一调制单元对应的第一调节单元的状态，将波长相同但入射角度不同的第一光束和第二光束中的一个沿第一方向出射。这样，可以根据需要灵活地控制第一光束或第二光束沿第一方向出射。本申请提供的光调制装置除了通过控制第一调制单元的调制相关参数来控制光束的出射方向之外，还可以通过控制第一调节单元的状态来控制光束的出射方向，增加了光束的出射方向的控制方式。
在本申请实施例中，第一调节单元还用于在第一状态下将接收到的第二光束B2导向第一调制单元。第一调制单元还用于将调制后的第二光束B2沿第二方向P2出射，第二方向P2与第一方向P1不同。由于第一光束和第二光束的波长相同，因此，在相同的调制相关参数下，调制后的第一光束和调制后的第二光束的偏转角度相同，但是由于第一光束和第二光束的入射角不同，所以调制后的第一光束和调制后的第二光束的出射方向不同。
当第一调节单元处于第一状态时，如果第二光束B2入射至光调制装置，该第二光束B2会被从不同于第一方向P1的第二方向P出射，避免影响沿第一方向P1出射的第一光束。因此，光调制装置可以在第二光束B2始终入射的情况下工作，以便在需要将第二光束出射至第一方向时快速将第二光束B2切换至从第一方向出射。避免在需要将第二光束B2出射至第一方向时，再将第二光束B2入射到光调制装置而导致等待时间过长。
空间光调制器是一种对光的空间分布进行调制的器件，在外部信号(电驱动信号)的控制下，改变空间上光分布的振幅(或强度)、相位、偏振态等。本申请实施例中的空间光调制器10主要用于改变空间上光分布的相位，可以被称为相位型空间光调制器。
可选地，空间光调制器10包括反射式空间光调制器和透射式空间光调制器。图1中以反射式空间光调制器为例进行了示例。在其他实施例中，空间光调制器10也可以为透射式空间光调制器。
反射式空间光调制器包括但不限于LCOS调制器和MEMS调制器。透射式空间光调制器包括但不限于LC调制器等。
需要说明的是，在其他实施例中，第一状态为反射状态，第一调节单元将第一光束反射至第一调制单元；第二状态为透射状态，第一调节单元将第二光束向第一方向透射。
还需要说明的是，在其他实施例中，空间光调制器10所包含的调制单元10a的数量可以多于光学调节层20中调节单元20a的数量，只要保证每个调节单元20a均对应有一个调制单元10a即可。这里，调节单元20a与调制单元10a对应，是指相对应的调节单元20a和调制单元10a之间的位置关系能够满足，当光束入射至第一状态下的调节单元20a时，调节单元20a能够将该光束导向对应的调制单元10a。
在本申请实施例中，透射状态和反射状态是相对的，透射状态下第一调节单元的透过率高于反射状态下第一调节单元的透过率，且透射状态下第一调节单元的反射率高于反射状态下第一调节单元的反射率。考虑到光效，透射状态下的透过率越接近100％越好，而反射状态下的反射率越接近100％越好。透射状态下的透过率和反射状态下的反射率由调节单元中的膜层结构参数和折射率参数决定。例如由下文中的光介质层的结构参数和折射率参数、折射率层可变层的结构参数和折射率参数决定。
图2是本申请实施例提供的一种光学调节层的俯视结构示意图。如图2所示，光学调节层20包括沿第一方向排列的多个调节单元20a。每个调节单元20a的状态均可以单独控制。
在本申请实施例中，每个调节单元20a用于入射不同波长的入射光束。例如，假设光学调节层20包括M个调节单元20a，则入射到每个调节单元20a的入射光束的波长分别为λ1～λM。其中，M为整数且大于1。图2中每个调节单元20a中的椭圆形表示不同波长的入射光束形成的光斑。从图2可以看出，不同波长的入射光束形成的光斑的排列方向与多个调节单元20a的排列方向相同，因此，第一方向也可以被称为波长排列方向。
在光通信系统中，波段1260nm～1625nm属于低损耗波长区域。波长在这个波长区域内的光适合在光纤中传输。这个波长区域被划分为五个波段，分别为常规(conventional，C)波段、长波长(long-wavelength，L)波段、短波长(short-wavelength，S)波段、原始(orignal，O)波段和扩展(extended，E)波段。其中，C波段表现出的损耗最低，通常为1530nm～1565nm。L波段是损耗第二低的波段，通常为1565nm～1625nm。S波段通常为1460nm～1530nm。O波段通常为1260nm～1360nm。E波段通常为 1360nm～1460nm。本申请实施例中，入射光束的波长可以属于该波段1260nm～1625nm。
图3是本申请实施例提供的一种调节单元的放大结构示意图。如图3所示，调节单元20a包括衍射光栅结构。该衍射光栅结构包括层叠的折射率可变层21和光介质层22。
当调节单元20a在第一状态时折射率可变层21具有第一折射率，当调节单元20a在第二状态时折射率可变层21具有第二折射率，第一折射率和第二折射率不同。也即是，在激励信号的作用下，折射率可变层21的折射率发生改变，折射率可变层21的折射率与光介质层22的折射率之间的关系也随之发生变化，从而使得调节单元20a的状态在第一状态和第二状态之间切换。
光介质层22的折射率与第一折射率或者第二折射率相匹配。在本申请实施例中，A的折射率与B的折射率相匹配是指A的折射率与B的折射率相同或者相近。例如，A的折射率与B的折射率之差与A的折射率的比值在10％之内，例如5％之内。
在一些示例中，当光介质层的折射率与折射率可变层的折射率相匹配时，光介质层和折射率可变层形成反射式衍射光栅；而当光介质层的折射率与折射率可变层的折射率不匹配时，光介质层和折射率可变层形成透射式衍射光栅。
在另一些示例中，当光介质层的折射率与折射率可变层的折射率相匹配时，光介质层和折射率可变层形成透射式衍射光栅；而当光介质层的折射率与折射率可变层的折射率不匹配时，光介质层和折射率可变层形成反射式衍射光栅。
在本申请实施例中，第一折射率和第二折射率的差值的绝对值的取值范围为0.5～10，该折射率差值可以使得折射率可变层的折射率发生变化时，衍射光栅结构在反射式衍射光栅和透射式衍射光栅之间切换，从而调节单元的状态能够相应发生变化。在一些示例中，第一折射率和第二折射率的差值的绝对值可以在0.7以上，甚至在1.0以上。而第一折射率和第二折射率的差值的绝对值的上限由材料的能力限制。
在本申请实施例中，折射率可变层21可以采用相变材料(phase change material，PCM)制成，即折射率可变层采用PCM制成。PCM具有结晶态(crystalline，简称C态)和非晶态(又称无定型态(amorphous，简称A态))。当PCM处于C态时具有第一折射率，当PCM处于A态时具有第二折射率，且第一折射率大于第二折射率。
PCM由C态切换为A态的速度非常快，当PCM由C态切换为A态对应下文中的假光填充状态时，可以实现亚ms的快速切换。
在本申请实施例中，每个调节单元包括一个波长像素或者包括阵列布置的多个波长像素，其中，波长像素可以理解为对光束进行单独调节的最小分辨率，每个波长像素对应一个最小波长范围。
假设每个调节单元包括一个波长像素，每个波长像素对应的PCM的总面积为19200μm。每个像素波长中的PCM由C态切换至A态的响应时间约1μs，功耗约2.5W；而每个像素波长中的PCM由A态切换至C态的响应时间约300ms，功耗约0.5W。
假设共有2400个波长像素，瞬态功耗10W。如果2400个波长像素均需要从透射状态切换到反射状态，则需要将2400个波长像素中的PCM均从C态转换为A态，共需要0.6ms(2400÷(10W÷2.5W)*1μs。如果2400个波长像素均需要从反射状态切换到透射状态，则需要将2400个调节单元中的PCM均从A态转换为C态，共需要36s(2400÷(10W÷0.5W)*300ms)。可见，调节单元从透射状态切换为反射状态的速度非常快。并且，由于PCM具有双稳态特性，仅在C态和A态的切换过程中消耗能量。而在非切换过程中无需消耗能量即可维持状态，并且具有较好的热稳定性(即在不同温度环境下可以保持稳态)，所以有利于节省光调制装置的功耗。
可选地，PCM可以采用以下材料中的任一种硒化锑(Sb2Se3)、硫化锑(Sb2S3)、硫化碲(TeS2)、锗锑碲(GST，例如Ge2Sb2Te5等)、三碲化七锑(Sb7Te3)、锗碲硫、锗砷硫、锗锑硒(GSSE，例如GeSbSe)、锗碲硒和锗锑硒碲(GSST，即GeSbSeTe)。
在一些示例中，PCM为硒化锑，当硒化锑处于C态时，折射率约为4.1。当硒化锑处于A态时，折射率约为3.3。光介质层的材料为硅，硅的折射率为3.5。当硒化锑处于A态时，折射率与硅的折射率相匹配。
在另一些示例中，PCM为GSST，当GSST处于C态时，折射率在5.1左右。当GSST处于A态时，折射率为3.4左右。光介质层的材料为硅，硅的折射率在3.5。当GSST处于A态时，折射率与硅的折射率相匹配。
需要说明的是，本申请对PCM的种类和光介质层的材料不做限制，只要能够满足PCM在A态(或者C态)时，PCM的折射率与光介质层的折射率相匹配；且PCM在C态(或者A态)时，PCM的折射率与光介质层的折射率相差较大即可。
PCM在受热时相态发生改变，例如，从C态切换至A态，或者从A态切换至C态。本申请实施例中，光介质层在电信号的作用下产生热量，从而使得PCM的相态发生变化。
在该实施例中，光介质层22可以采用透明导电材料制成，例如石墨烯、ITO、IZO和掺杂的硅材料等。这样，可以直接利用光介质层在激励信号的作用产生热量，使得相变材料的相态变化，从而使得折射率可变层的折射率变化。这种实施方式中，光介质层即作为衍射光栅结构的一部分，又起到导电的作用，有利于简化调节单元的结构。
图4为图3所示调节单元的沿A-A线的截面结构示意图。结合图3和图4，折射率可变层21包括阵列布置的多个第一块状结构211。示例性地，多个第一块状结构211采用一维阵列布置，且多个第一块状结构211沿第一方向排列。光介质层22包括阵列布置的多个第二块状结构221，多个第二块状结构221同样沿第一方向排列。多个第一块状结构211的排列方向与多个调节单元20a的排列方向相同，例如，均为左右排列。第一块状结构211和第二块状结构221均为长条形结构。第一块状结构211和第二块状结构221的长度方向一致，且第一块状结构211的长度方向与多个第一块状结构211的排列方向垂直。
第二块状结构221与第一块状结构211一一对应连接，第一块状结构211的宽度与第二块状结构221的宽度相等。第一方向与折射率可变层21和光介质层22的层叠方向垂直。这里，宽度是指第一方向上的尺寸。
在一些示例中，光介质层22的折射率与第二折射率相匹配。当第一块状结构的折射率为第一折射率时，第一块状结构的折射率大于第二块状结构的折射率，调节单元处于透射状态。当第一块状结构的折射率为第二折射率时，第一块状结构的折射率基本等于第二块状结构的折射率，调节单元处于反射状态。
在另一些示例中，光介质层22的折射率与第一折射率相匹配。当第一块状结构的折射率为第一折射率时，第一块状结构的折射率基本等于第二块状结构的折射率，调节单元处于透射状态。当第一块状结构的折射率为第二折射率时，第一块状结构的折射率小于第二块状结构的折射率，调节单元处于反射状态。
可选地，光介质层22还包括两个连接条222，多个第二块状结构221的一端与一个连接条222连接，多个第二块状结构221的另一端与另一个连接条222连接。可替代地，在其他实施例中，可以将第X-1个第二块状结构221的第一端和第X个第二块状结构221的第一端通过一个连接条连接，将第X个第二块状结构221的第二端与第X+1个第二块状结构221的第二端通过另一个连接条连接。通过连接条将同一调节单元中的所有第二块状结构连接在一起，以便于与电信号输入端(例如图中的VCC和GND)连接。
可替代地，在其他实施例中，光介质层22采用透明绝缘材料制成。调节单元20a还包括透明导电层(图未示)，透明导电层可以位于光介质层的表面或者位于折射率可变层的表面。透明导电层在激励信号作用下，产生热量，热量传导至折射率可变层使得相变材料的相态变化，从而使得折射率可变层的折射率变化。
示例性地，透明绝缘材料包括但不限于硅、二氧化钛、氮化硅、碳化硅和氮氧化硅。
当透明导电层位于光介质层的表面时，透明绝缘材料可以采用传热性能较好的材料，以便快速将透明导电层产生的热量传导至折射率可变层。
如图3和图4所示，光学调节层20还包括基底23，多个调节单元20a阵列布置在基底23的第一表面。该基底的第二表面与空间光调制器直接或者间接连接。
示例性地，基底23可以采用硅或者二氧化硅等材料制成。
先在基底23上制作调节单元20a，然后再将基底23与空间光调制器10连接，制作方便，并且可以避免在调节单元20a的制作过程中，对空间调制器10产生不良影响。
在一些示例中，基底23的材料与第二块状结构221的材料相同，例如均为硅。这种情况下，基底23与第二块状结构221可以为一体结构。例如，通过对硅片的表面进行图案化处理得到具有凸起结构的基底23，该凸起结构即为第二块状结构221。
在另一些示例中，基底23的材料可以与空间光调制器10中的盖板的材料相同，例如均为二氧化硅，这样，可以减少从光在基底23和空间光调制器10的界面上的反射。
在其他实施例中，基底23还可以采用其他的透明材料制成。
在其他实施例中，折射率可变层和光介质层可以直接形成在空间光调制器10的表面，即光学调节层不包括基底23。
如图4所示，光学调节层20还包括覆盖层24，覆盖层24填充于调节单元20a中相邻的第一块状结构211以及相邻的第二块状结构221之间且覆盖折射率可变层21，覆盖层24还填充于相邻的调节单元20a之间。该覆盖层可以起到保护折射率可变层和光介质层的作用，并且，覆盖层的表面平坦，便于与其他表面连接。
该覆盖层24为可选结构，在一些示例中，光学调节层20可以不包括覆盖层24，由空气填充在相邻的第一块状结构211以及相邻的第二块状结构221之间。
示例性地，覆盖层24的折射率与第一折射率之间的差值的绝对值大于0.5和/或覆盖层24的折射率与第二折射率之间的差值的绝对值大于0.5，以形成衍射光栅结构。例如，覆盖层24的材料可以为二氧化硅等。
可选地，光学调节层20还包括增透膜层25，增透膜层25位于覆盖层24上。该增透膜层用于提高入射光束所属光通信波段(例如C波段、L波段或者S波段)的透射率。示例性地，增透膜层可以为多层介质材料膜。
示例性地，折射率可变层21的厚度大于0且不大于150nm，例如20nm～30nm。光学介质层22的厚度不大于1.5μm。例如，450nm～500nm。光栅周期小于调节单元对应的波长，例如约为750nm，占空比可以为5％～95％，在一些示例中，占空比可以为30～70％，例如50％。
这一些示例中，所有调节单元20a中衍射光栅结构的形状和尺寸均相同，以简化光学调节层的制作工艺。在另一些示例中，不同波长对应的调节单元20a中衍射光栅结构的形状和/或尺寸不同，以提高光学调节层的控制精度。
图5是本申请实施例提供的另一种调节单元的俯视结构示意图。图6是图5所示调节单元沿B-B线的截面结构示意图。如图5和图6所示，该调节单元20a中的多个第一块状结构211的排列方向与多个调节单元20a的排列方向垂直。如图2所示，多个调节单元20a的排列方向沿左右方向，而图5中多个第一块状结构211的排列方向为上下方向。第一块状结构211的长度方向与多个调节单元20a的排列方向一致。该调节单元20a的截面结构与图4相同，在此不再详细描述。
图7是本申请实施例提供的又一种调节单元的俯视结构示意图。图8为图7中的调节单元沿C-C线的截面结构示意图。如图7和图8所示，多个第一块状结构211采用二维阵列布置，即呈矩阵布置。
如图8所示，第一块状结构211和第二块状结构221均为柱状结构，第一块状结构221的长度方向(即图8中的上下方向)与多个第一块状结构221的第一排列方向和第二排列方向均垂直，且与折射率可变层21和光介质层22的层叠方向平行。该第一排列方向和第二排列方向分别为矩阵的行方向和列方向。
图8中调节单元20a的层级结构与图4相比去除了增透膜层25，其他结构与图4基本相同，在此不再详细描述。
需要说明的是，在图3至图8所示实施例中，均以光介质层22和折射率可变层21依次层叠在基底23上为例进行了说明，在其他实施例中，也可以是折射率可变层21和光介质层22依次层叠在基底23上，只要能够保证在折射率可变层21具有不同的折射率时，与光介质层22配合能够分别形成反射式衍射光栅和透射式衍射光栅即可。
图9为本申请实施例提供的另一种光调制装置的结构示意图。如图9所示，光调制装置包括空间光调制器10和光学调节层20。光学调节层20与空间光调制器10的表面连接。
在图9中，空间光调制器10为LCOS调制器。该空间光调制器10包括依次层叠的背板11、第一电极层12、液晶层13、第二电极层14和透明盖板15。
背板11包括阵列布置的多个驱动电路(图未示)。第一电极层12包括多个第一电极121(又称像素电极)。一个调制单元对应一个第一电极121或者对应阵列布置的多个第一电极121。每个第一电极121与一个驱动电路连接，第二电极层14包括多个第二电极，多个第二电极为一体结构。例如，第二电极层14为整面结构。每个驱动电路用于向所连接的第一电极提供电压，以改变该第一电极与第二电极之间的电场，使得液晶分子的偏转方向发生变化，从而改变了液晶的有效折射率来改变光经过的光程的大小，达到相位调制的目的。
其中，第一电极层12和第二电极层13均为透明的导电材料层，例如氧化铟锡(indium tin oxide，ITO)层、氧化铟锌(indium zinc oxide，IZO)层等。示例性地，透明盖板15为玻璃盖板和塑料盖板等。
可选地，如图9所示，该光调制装置还包括预偏转层30。该预偏转层30位于空间光调制器10和光学调节层20之间。该预偏转层30用于对入射光束的传播方向进行设定角度的偏转。在一些示例中，该预偏转层30可以对所有入射光束的入射角进行相同角度的偏转，或者，按照波长对入射光束的入射角进行不同角度的偏转。
图10为本申请实施例提供的一种预偏转层的俯视结构示意图。如图10所示，该预偏转层30包括阵列布置的多个偏转单元30a。多个偏转单元30a与多个调节单元20a一一对应。与第一调节单元的第一偏转单元位于第一调节单元和第一调节单元之间的光路上，第一偏转单元用于将第一调节单元的光偏转设定角度后出射至第一调制单元。示例性地，该设定角度大于0°小于10°。
图11为本申请实施例提供的一种偏转单元的放大结构示意图。如图11所示，该偏转单元30a为周期结构，偏转单元30a中的多个周期30b的排列方向垂直于多个偏转单元30a的排列方向。每个周期30b包括沿偏转单元30a的排列方向延伸的条形结构。
图12为图11所示的偏转单元的截面结构示意图。如图12所示，该偏转单元30a包括第一介质层31和第二介质层32。其中，第一介质层31的折射率不等于第二介质层32的折射率。例如，第一介质层31的折射率大于第二介质层32的折射率，或者，第一介质层31的折射率小于第二介质层32的折射率。
第一介质层31为闪耀光栅。闪耀光栅的每个楔形凸起为周期结构中的一个周期。
示例性地，第一介质层31的材料可以为硅、二氧化硅、氮化硅、氮氧化硅和碳化硅等，第二介质层32的材料可以为硅、二氧化硅、氮化硅、氮氧化硅和碳化硅等。为了满足第一介质层31和第二介质层32的折射率不同，第一介质层31和第二介质层32通常采用不同的材料形成。
图13为本申请实施例提供的另一种偏转单元的截面结构示意图。如图13所示，与图12所示的偏转单元的区别在于，第一介质层31包括平行布置的多个条形结构。每个周期中的多个条形结构的间距渐变，形成间距渐变的光栅结构。
这里，间距渐变的光栅结构是指，光栅中相邻两个条形结构之间的间距是不相等且逐渐变化的(例如线性变化等)。例如，在图13中，按照从上到下的方向，每个非等间隔光栅中相邻两个条形结构之间的间距是逐渐减小的。
可替代地，每个周期中的多个条形结构还可以形成非等占空比光栅结构。这里，非等占空比光栅结构是指，光栅中的条形结构的宽度与所在光栅周期的比值是不相等的。
图14为本申请实施例提供的有一种偏转单元的截面结构示意图。如图14所示，与图12所示的偏转单元的区别在于，第一介质层31包括多个DOE，多个DOE的排列方向与多个偏转单元30a的排列方向垂直。每个DOE均为多层台阶结构。每个DOE为周期结构中的一个周期。
例如，在图14中，按照从上到下的方向，每个DOE的台阶的层数是逐渐增大的。图14中以4个台阶为例进行了示意，但本申请实施例对台阶的数量不做限制，可以根据需要设置。
在一些示例中，每个偏转单元30a中的第一介质层31具有相同的形貌，在忽略色散的情况下，可以对所有波长的光束进行相同角度的偏转。在另一些示例中，不同偏转单元30a中的第一介质层31具有与波长对应的形貌，不同波长对应的形貌不同，从而可以对不同波长的光束进行不同角度的偏转。
图15为图9所示光调制装置在光学调节层处于第一状态下的光的传播路径的示意图。如图15所示，第一光束B1入射至光学调节层20的第一调节单元。光学调节层20处于透射状态，将第一光束B1透射至预偏转层30。预偏转层30将第一光束B1偏转一定角度后出射至空间光调制器10。空间光调制器10对第一光束B1进行相位调制后反射，第一光束B1对应的反射光束依次经过预偏转层30和光学调节层20后出射至第一方向P1。
第二光束B2入射至光学调节层20的第一调节单元，光学调节层20处于透射状态，将第二光束B2透射至预偏转层30。预偏转层30将第二光束B2偏转一定角度后出射至空间光调制器10。空间光调制器10对第二光束B2进行相位调制后反射，第二光束B2对应的反射光束再次经过预偏转层30偏转相同角度后，经过光学调节层20出射至第二方向P2。
需要说明的是，图15中显示的是第一光束B1和第二光束B2在偏转相同角度后的传播方向到达空间 光调制器10，例如，均向左偏转一定角度后到达空间光调制器。而由空间光调制器10出射的第一光束B1和第二光束B2也向左偏转相同角度后经过光学调节层20出射。
图16为图10所示的光调制装置在光学调节层处于第二状态下的光的传播路径的示意图。如图16所示。第二光束B2入射至光学调节层20的第一调节单元。第一调节单元处于反射状态，第一调节单元将第一光束B1反射至第一方向P1。
图17是本申请实施例提供的又一种光调制装置的结构示意图。如图17所示，预偏转层位于透明盖板15和第二电极层14之间。可替代地，在其他实施例中，透明盖板为双层结构，预偏转层可以夹设于两层盖板之间。
图18是本申请实施例提供的又一种光调制装置的结构示意图。如图18所示，该光调制装置还包括转折棱镜40和反射元件50，转折棱镜40的第一表面与空间光调制器10的表面连接，转折棱镜40的第二表面与光学调节层20连接，反射元件50和空间光调制器10分别位于光学调节层20的两侧。转折棱镜40的第三表面为入射光束的入射面。
示例性地，转折棱镜40为直角棱镜，第一表面为直角棱镜的一个直角面，第二表面为直角棱镜的斜面，第三表面为直角棱镜的另一个直角面。
在图18所示的光调制装置中，第一状态为反射状态，第二状态为透射状态。
在图18中，反射元件50与预偏转层30集成在一起。例如，反射元件50为位于预偏转层30的远离光学调节层20的表面的反射层。
图19为图18中的预偏转层的一个偏转单元的一种截面结构示意图。如图19所示，该偏转单元30a包括第一介质层31和反射层。第一介质层31具有闪耀光栅的形貌。也即是，第一介质层31的表面具有多个长条形凸棱，每个长条形凸棱的长度方向均与多个偏转单元30a的排列方向平行。每个长条形凸棱均包括相连的第一表面和第二表面。多个长条形凸棱的第一表面相互平行，且多个长条形凸棱的第二表面相互平行。反射层覆盖在第二表面。
示例性地，第一介质层31可以为二氧化硅层、硅层、氮化硅层、氮氧化硅层和碳化硅层。反射层50为金属层，尤其是在光通信波段(例如1550nm波段)高反射的金属层，例如Al层、Ag层和Au层等。
图20为图18所示的光调制装置在在光学调节层处于第一状态下的光的传播路径的示意图。如图20所示，转折棱镜40位于第一光束B1和第二光束B2的入射光路上，第一光束B1和第二光束B2透过转折棱镜40入射至光学调节层20。光学调节层20中的各个调节单元均处于反射状态，光学调节层20将第一光束B1反射至空间光调制器10。空间光调制器10将第一光束B1经过角度偏转后，出射至光学调节层20，经光学调节层20反射后沿第一方向P1出射。空间光调制器10将第二光束B2经角度偏转后，出射至光学调节层20，经光学调节层20反射后沿第二方向P2出射。
图21为图18所示的光调制装置在光学调节层处于第二状态下的光的传播路径的示意图。如图21所示。第二光束B2透过转折棱镜40入射至光学调节层20。光学调节层20中的对应的调节单元处于透射状态，光学调节层20将第二光束B2透射至预偏转层30。第二光束B2经过预偏转层30偏转以及反射元件50反射后，沿第一方向P1出射。
图22为本申请实施例提供的又一种光调制装置的结构示意图。如图22所示，该光调制装置的结构与图18中的光调制装置的结构基本相同，区别在于，图22中的光调制装置还包括另一转折棱镜60。该另一转折棱镜60的一个表面与光学调节层20连接，该另一转折棱镜60的另一个表面与预偏转层30连接。且该预偏转层30所在的表面与入射面相对。
图23为图22中的预偏转层的一个偏转单元的另一种截面结构示意图。如图20所示，该偏转单元30a包括第一介质层31和反射层50。该第一介质层31具有第一表面和第二表面，第一表面为平面，且与该另一转折棱镜60的表面连接，第二表面与第一表面呈夹角。反射层50位于第二表面。
图24为图22中的光调制装置在在光学调节层处于第一状态下的光的传播路径的示意图。如图24所示，第一光束B1和第二光束B2透过转折棱镜40入射至光学调节层20。光学调节层20中的各个调节单元均处于反射状态，光学调节层20将第一光束B1和第二光束B2反射至空间光调制器10。空间光调制器10将第一光束B1经过角度偏转后，出射至光学调节层20，经光学调节层20反射后沿第一方向P1出射。 空间光调制器10将第二光束B2经角度偏转后，出射至光学调节层20，经光学调节层20反射后沿第二方向P2出射。
图25为图22所示的光调制装置在光学调节层处于第二状态下的光的传播路径的示意图。如图25所示，第二光束B2透过转折棱镜40入射至光学调节层20。光学调节层20中的对应的调节单元处于透射状态，光学调节层20将第二光束B2透射至预偏转层30。第二光束B2经过预偏转层30偏转以及反射元件50反射后，沿第一方向P1出射。
图26为本申请实施例提供的又一种光调制装置的结构示意图。如图26所示，在图22的基础上，该光调制装置还包括偏振分束器70和反射式波片80，偏振分束器70位于转折棱镜40的入射面，即位于第二光束B2的入射光路上。偏振分束器70与空间光调制器10连接。反射式波片80位于偏振分束器70的与空间光调制器10所在面相对的表面。
图27为图26中的光调制装置在光学调节层处于第一状态下的光的传播路径的示意图。如图27所示，偏振分束器70用于将第二光束B2透射至光学调节层20。其中，第二光束B2为具有第一偏振方向的线偏振光，能够直接透过偏振分束器70，经过转折棱镜40后入射至光学调节层20。
偏振分束器70还用于将第四光束分为第一光束B1和第三光束B3，第一光束B1为具有第一偏振方向的线偏振光，第三光束B3为具有第二偏振方向的线偏振光；将第一光束B1向光学调节层20出射，将第三光束B3向反射式波片80出射，反射式波片80用于将第三光束B3转换为具有第一偏振方向的线偏振光后向空间光调制器10出射，该空间光调制器10还用于将第三光束B3沿第一方向出射。第一光束B1和第二光束B2在到达空间光调制器10后的传播路径参见图24。
该第四光束可以为经过长距离光纤传输后的信号光。经过长距离光纤传输后，信号光的偏振态会发生随机变化。先通过偏振分束器将第四光束分为偏振方向不同的线偏振光，将具有第一偏振方向的线偏振光直接向空间光调制器出射，并利用反射式波片将具有第二偏振方向的线偏振光转换为具有所述第一偏振方向的线偏振光后向所述空间光调制器出射，能够对第四光束进行偏振复用处理，简化光学设计。
示例性地，第一偏振方向和第二偏振方向垂直，例如，第一偏振方向的线偏振光为P光，第二偏振方向的线偏振光为S光。反射式波片为1/4波片。
图28为图26所示的光调制装置在光学调节层处于第二状态下的光的传播路径的示意图。如图28所示，第二光束B2入射至光学调节层20。光学调节层20中的对应的调节单元处于透射状态，光学调节层20将第二光束B2透射至预偏转层30。第二光束B2经过预偏转层30偏转以及反射元件50反射后，沿第一方向P1出射。
本申请实施例提供的光调制装置不包含机械结构和有机材料，器件寿命和可靠性较高。该光调制装置可以集成在WSS中，插损小、结构简单且成本低。下面对集成有光调制装置的WSS的结构进行详细说明。
本申请实施例还提供了一种WSS。图29为本申请实施例提供的一种WSS的结构示意图。图30是图29的侧视图。如图29和图30所示，该WSS包括接口单元1、分波单元2和光调制装置3。光调制装置3为前述调制装置中的任一种。
其中，接口单元1包括M个输入端口和N个输出端口，所述M个输入端口和所述N个输出端口阵列布置，其中，M和N均为整数，且M和N中的至少一个大于1。每个端口与一根光纤连接。每根光纤中传播的光信号均采用波分复用的方式，即每个光纤均支持多个波长的光通道。不同的输入端口中传输的信号光的波长可以不同。
示例性地，接口单元1中包括M个输入端口和1个输出端口，且M个输入端口和1个输出端口并排布置。这里，接口单元1中的各个端口的排列方向与前述波长排列方向垂直。例如，图29中，接口单元1包括3个输入端口(分别为端口IN0～IN2)和1个输出端口(端口OUT)。端口的排列方向为平行于纸面的上下方向，而波长排列方向为垂直于纸面的方向。
如图29和图30所示，分波单元2包括分波器件2a和光路调整器件2b。其中分波器件2a用于将各个输入端口输入的光按照波长进行分光，并将分光后得到的各个波长的光束导向光路调整器件2b。光路调整器件2b用于将各个波长的光束导向光调制装置3中波长对应的调节单元。
示例性地，分波器件2a可以包括衍射光栅等。光路调整器件2b可以包括球面镜等。
图29和图30中的光调制装置为图1所示结构为例进行了示意，在其他实施例中，也可以采用前述任一种光调制装置。
如图29所示，3个输入端口中的输入端口IN1和IN2分别与一个节点连接；输入端口IN0与假光光源连接。其中，输入端口IN1中传输的信号光的波长为λ1和λ3，输入端口IN2中传输的信号光的波长为λ2。
当WSS处于正常工作状态时，光学调节层20的各个调节单元均处于透射状态。合波信号通过接口单元1中的输入端口到达分波单元2。分波单元2中的分波器件2a对来自各个输入端口的合波信号按照波长进行分光，并将各个波长的光经由光路调整器件2b传输至光调制装置3中对应的调节单元。由于调节单元处于透射状态，所以各个波长的光透过光学调节层，进一步传输至空间光调制器。空间光调制器的各个调制单元控制液晶分子的排列，形成特定的相位型衍射光栅，从而对相应波长的光束进行偏转后反射。反射光束回到分波单元2的光路调整器件2b，角度偏转转换为位置移动，经过光路调整器件2b后由分波器件2a对各个波长的光束进行合波，并将合波后的光束从输出端口OUT输出。同时，输入端口IN0输入的波长为λ1、λ2和λ3的假光，均输出至非端口位置。这里，输出端口OUT与前述第一方向对应，非端口位置与前述第二方向对应。其中，不同波长的假光可以出射至不同的非端口位置，例如，图29中，波长λ1和λ3的假光出射至非端口位置X1，波长λ2的假光出射至非端口位置X2。
图31为图29所示的WSS的另一种工作状态示意图。图32是图31的侧视图。WSS的该工作状态可以被称为假光填充状态。如图31和图32所示，输入端口IN2中输入的波长为λ2的信号光突发中断，则控制光学调节层20中与波长λ2对应的调节单元从透射状态切换为反射状态，波长为λ2的假光被对应的调节单元反射至分波单元2。光学调节层20中的其他调节单元仍然保持透射状态，因此，输入端口IN1输入的波长为λ1和λ3的信号光的传播路径以及从输入端口IN0输入的波长为λ1和λ3的假光的传播路径与图29相同。
分波单元2将波长为λ2的假光和波长为λ1和λ3的一起从输出端口OUT输出，使得输出端口OUT仍然保持波长λ1、λ2和λ3的满波状态，抑制受激拉曼散射(stimulated Raman scattering，SRS)和对应的烧孔效应，保持各个波长的光信号的功率稳定。
从图29中可以看出，输入端口IN0、输入端口IN1以及输入端口IN2、输出端口OUT关于主光轴对称布置，当光调制装置不包括预偏转层且光学调节层处于反射状态时，假光的0级衍射光会直接入射到输出端口OUT中，端口隔离度较差。
当光调制装置3包括预偏转层时，例如光调制装置3为图9或者图17所示的光调制装置时，该预偏转层可以对到达空间光调制器的光束进行预偏转，使得假光的0级衍射光不再直接入射到输出端口OUT中，提高WSS的端口隔离度。
本申请实施例还提供了一种光通信设备。图33是本申请实施例提供的一种光通信设备的结构示意图。如图33所示，该光通信设备300包括假光光源301和WSS 302。其中，假光光源301与WSS 302的第一输入端口连接。
该假光光源301用于发射假光(dummy light)，该假光通常为未经调制的光信号。该假光为提供宽谱光信号，假光的波长范围与WSS的工作波长范围至少部分重叠。假光的波长范围至少包括前述第二光束的波长。
在一些示例中，假光的波长范围包括WSS的工作波长范围。这样，无论哪个波长的信号光发生掉波，均可以实现假光填充。
示例性地，该光通信设备包括可重构光分插复用器(reconfigurable optical add-drop multiplexer，ROADM)、光交叉互连(optical cross connect，OXC)或者其他类型的光交换/光调度设备。
图34是本申请实施例提供的又一种光通信设备的结构示意图。如图34所示，该光通信设备300包括假光光源301、WSS 302、本地上波模块303和光放大器304。WSS 302的一个输入端口与假光光源301连接。WSS302的其他输入端口分别与其他节点和本地上波模块303连接。WSS 302的输出端口与光放大器304的输入端口连接，光放大器304的输出端口与光纤连接。该光通信设备300与其他节点一起构成一个前向传输网络。
当节点1与WSS 302的输入端口之间的光纤中断时，来自节点1的光信号掉波。此时光放大器304对应波长信号突发缺失，由于SRS效应存在，会引起其他波长信号的功率波动，造成信号损伤。此时，利用假光光源301提供的相应波长的假光对掉波的光信号进行填充，以避免信号损伤。
实现时，可以通过光功率检测装置对WSS的各个输入端口的光信号进行监测，以便及时发现光信号掉波的情况。
在本申请实施例中，为了方便区分，图中采用虚线表示第二光束和假光，采用实现表示第一光束和信号光。
除非另作定义，此处使用的技术术语或者科学术语应当为本公开所属领域内具有一般技能的人士所理解的通常意义。本公开专利申请说明书以及权利要求书中使用的“第一”、“第二”、“第三”以及类似的词语并不表示任何顺序、数量或者重要性，而只是用来区分不同的组成部分。同样，“一个”或者“一”等类似词语也不表示数量限制，而是表示存在至少一个。“包括”或者“包含”等类似的词语意指出现在“包括”或者“包含”前面的元件或者物件涵盖出现在“包括”或者“包含”后面列举的元件或者物件及其等同，并不排除其他元件或者物件。“A和/或B”表示存在以下三种情况：A、B、以及A和B。
以上仅为本申请一个实施例，并不用以限制本申请，凡在本申请的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本申请的保护范围之内。

Claims (19)

  1. 一种光调制装置，其特征在于，包括：空间光调制器和光学调节层；
    所述空间光调制器包括阵列布置的多个调制单元；
    所述光学调节层包括阵列布置的多个调节单元，所述多个调节单元分别与所述多个调制单元中的一个调制单元对应；
    所述多个调节单元中的第一调节单元被配置为在激励信号作用下在第一状态和第二状态之间切换，所述第一调节单元为所述多个调节单元中的任一个；
    所述第一调节单元用于在所述第一状态下，将接收到的第一光束导向第一调制单元，所述第一调制单元用于对来自所述第一调节单元的所述第一光束进行调制，以及将调制后的第一光束沿第一方向出射；或者，所述第一调节单元用于在所述第二状态下，将接收到的第二光束沿所述第一方向出射；
    其中，所述第一调制单元为所述多个调制单元中与所述第一调节单元对应的调制单元，所述第二光束的波长与所述第一光束的波长相同，且所述第二光束入射至所述第一调节单元的入射角与所述第一光束入射至所述第一调节单元的入射角不同。
  2. 根据权利要求1所述的光调制装置，其特征在于，所述第一调节单元还用于在所述第一状态下，将接收到的所述第二光束导向所述第一调制单元；
    所述第一调制单元还用于对来自所述第一调节单元的所述第二光束进行调制，以及将调制后的第二光束沿第二方向出射。
  3. 根据权利要求1或2所述的光调制装置，其特征在于，所述第一调节单元包括衍射光栅结构，所述衍射光栅结构包括层叠在所述空间光调制器上的折射率可变层和光介质层；
    所述折射率可变层包括阵列布置的多个第一块状结构，所述光介质层包括阵列布置的多个第二块状结构，所述第二块状结构与所述第一块状结构一一对应连接；
    所述折射率可变层被配置为当所述第一调节单元在所述第一状态时具有第一折射率，当所述第一调节单元在所述第二状态时具有第二折射率，所述第一折射率和所述第二折射率不同，所述光介质层的折射率与所述第一折射率或者所述第二折射率匹配。
  4. 根据权利要求3所述的光调制装置，其特征在于，所述第一调节单元中，所述第一块状结构和所述第二块状结构采用以下结构中的任一种：
    所述多个第一块状结构一维阵列布置，所述第一块状结构和所述第二块状结构均为长条形结构，所述第一块状结构的长度方向与所述多个第一块状结构的排列方向垂直，且与所述折射率可变层和所述光介质层的层叠方向垂直；
    所述多个第一块状结构二维阵列布置，所述第一块状结构和所述第二块状结构均为柱状结构，所述第一块状结构的长度方向与所述多个第一块状结构的任一排列方向垂直，且与所述折射率可变层和所述光介质层的层叠方向平行。
  5. 根据权利要求3或4所述的光调制装置，其特征在于，所述光学调节层还包括基底，所述多个调节单元阵列布置在所述基底的第一表面。
  6. 根据权利要求3至5任一项所述的光调制装置，其特征在于，所述光学调节层还包括覆盖层，所述覆盖层填充于任意相邻的两个所述第一块状结构和任意相邻的两个所述第二块状结构之间且覆盖所述折射率可变层。
  7. 根据权利要求6所述的光调制装置，其特征在于，所述光学调节层还包括增透膜层，所述增透膜层位于所述覆盖层上。
  8. 根据权利要求1至7任一项所述的光调制装置，其特征在于，所述第一状态为透射状态，所述第二状态为反射状态；
    所述光学调节层与所述空间光调制器的表面连接。
  9. 根据权利要求1至7任一项所述的光调制装置，其特征在于，所述第一状态为反射状态，所述第二状态为透射状态；
    所述光调制装置还包括转折棱镜和反射元件，所述转折棱镜位于所述第一光束和所述第二光束的入射光路上，所述转折棱镜的第一表面与所述空间光调制器的表面连接，所述转折棱镜的第二表面与所述光学调节层连接，所述反射元件和所述空间光调制器分别位于所述光学调节层的两侧。
  10. 根据权利要求9所述的光调制装置，其特征在于，所述光调制装置还包括：偏振分束器和反射式波片；
    所述偏振分束器位于所述第二光束的入射光路上，所述偏振分束器用于将所述第二光束透射至所述光学调节层，其中，所述第一光束为具有第一偏振方向的线偏振光；
    所述偏振分束器还用于将第四光束分为所述第一光束和第三光束，所述第一光束为具有所述第一偏振方向的线偏振光，所述第三光束为具有第二偏振方向的线偏振光；将所述第一光束向所述光学调节层出射，将所述第三光束向所述反射式波片出射，所述反射式波片用于将所述第三光束转换为具有所述第一偏振方向的线偏振光后向所述空间光调制器出射。
  11. 根据权利要求1至10任一项所述的光调制装置，其特征在于，所述空间光调制装置还包括预偏转层，所述预偏转层包括阵列布置的多个偏转单元，所述多个偏转单元与所述多个调节单元一一对应；
    所述多个偏转单元中与所述第一调节单元的第一偏转单元位于所述第一调节单元和所述第一调制单元之间的光路上，所述第一偏转单元用于将所述第一调节单元的光偏转设定角度后出射至所述第一调制单元。
  12. 根据权利要求11所述的光调制装置，其特征在于，所述多个偏转单元中的任一偏转单元包括闪耀光栅、衍射光学元件、间距渐变的光栅结构或者占空比渐变的光栅结构。
  13. 根据权利要求3至7任一项所述的光调制装置，其特征在于，所述第一折射率和所述第二折射率的差值的绝对值的取值范围为0.5～10。
  14. 根据权利要求3至7中任一项或者权利要求13所述的光调制装置，其特征在于，所述折射率可变层采用相变材料形成，所述相变材料选自以下材料中的任一种：硒化锑、硫化锑、硫化碲、锗锑碲、三碲化七锑、锗碲硫、锗砷硫、锗碲硒和锗锑硒碲。
  15. 根据权利要求14所述的光调制装置，其特征在于，所述光介质层采用透明导电材料制成；
    或者，所述光介质层采用透明绝缘材料制成，所述调节单元还包括透明导电层，所述透明导电层位于所述光介质层的表面或者位于所述折射率可变层的表面。
  16. 根据权利要求3至7中任一项或者权利要求13至15中任一项所述的光调制装置，其特征在于，所述光介质层的材料选自以下任一种：透明导电材料、硅、二氧化钛、氮化硅、碳化硅和氮氧化硅。
  17. 根据权利要求1至16任一项所述的光调制装置，其特征在于，所述空间光调制器为硅基液晶LCOS调制器、微机电系统MEMS调制器和液晶调制器中的任一种。
  18. 一种波长选择开关，其特征在于，所述波长选择开关包括接口单元、分波单元和光调制装置；
    所述接口单元包括M个输入端口和N个输出端口，所述M个输入端口和所述N个输出端口阵列布置，其中，M和N均为整数，且M和N中的至少一个大于1；
    所述光调制装置为如权利要求1至16任一项所述的光调制装置；
    所述分波单元用于将来自所述M个输入端口的光束进行分波，得到多个波长的光束，将不同波长的光束输出至所述光调制装置的不同调节单元；以及将所述光调制装置出射至所述第一方向的光束输出至所述N个输出端口中的一个。
  19. 一种光通信设备，其特征在于，所述光通信设备包括假光光源和如权利要求18所述的波长选择开关，所述假光光源与所述波长选择开关的第一输入端口连接，所述假光光源用于提供假光，所述假光的波长范围与所述波长选择开关的工作波长范围至少部分重叠，所述第二光束为所述假光的一部分。
PCT/CN2023/104940 2022-09-27 2023-06-30 光调制装置、波长选择开关和光通信设备 WO2024066614A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202211183240.0 2022-09-27
CN202211183240.0A CN117826453A (zh) 2022-09-27 2022-09-27 光调制装置、波长选择开关和光通信设备

Publications (1)

Publication Number Publication Date
WO2024066614A1 true WO2024066614A1 (zh) 2024-04-04

Family

ID=90475918

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2023/104940 WO2024066614A1 (zh) 2022-09-27 2023-06-30 光调制装置、波长选择开关和光通信设备

Country Status (2)

Country Link
CN (1) CN117826453A (zh)
WO (1) WO2024066614A1 (zh)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001036142A (ja) * 1999-07-16 2001-02-09 Yazaki Corp 光通信システム用光源及び光通信システム
CN106772813A (zh) * 2016-12-16 2017-05-31 中央民族大学 基于相位光栅阵列的分辨率可调波长选择开关及控制方法
CN112415737A (zh) * 2019-08-20 2021-02-26 三星电子株式会社 光调制器件和包括光调制器件的电子装置
CN112415785A (zh) * 2020-10-10 2021-02-26 浙江大学 一种基于相变材料的空间光调制系统
CN114070450A (zh) * 2020-07-30 2022-02-18 华为技术有限公司 光传输的方法、装置、计算设备和存储介质
CN216310318U (zh) * 2021-12-10 2022-04-15 中央民族大学 一种折叠型m×n端口波长选择开关
CN114765477A (zh) * 2021-01-14 2022-07-19 华为技术有限公司 产生假光信号的装置、方法以及可重构光分插复用器

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001036142A (ja) * 1999-07-16 2001-02-09 Yazaki Corp 光通信システム用光源及び光通信システム
CN106772813A (zh) * 2016-12-16 2017-05-31 中央民族大学 基于相位光栅阵列的分辨率可调波长选择开关及控制方法
CN112415737A (zh) * 2019-08-20 2021-02-26 三星电子株式会社 光调制器件和包括光调制器件的电子装置
CN114070450A (zh) * 2020-07-30 2022-02-18 华为技术有限公司 光传输的方法、装置、计算设备和存储介质
CN112415785A (zh) * 2020-10-10 2021-02-26 浙江大学 一种基于相变材料的空间光调制系统
CN114765477A (zh) * 2021-01-14 2022-07-19 华为技术有限公司 产生假光信号的装置、方法以及可重构光分插复用器
CN216310318U (zh) * 2021-12-10 2022-04-15 中央民族大学 一种折叠型m×n端口波长选择开关

Also Published As

Publication number Publication date
CN117826453A (zh) 2024-04-05

Similar Documents

Publication Publication Date Title
JP5730526B2 (ja) 光スイッチ
US7231110B2 (en) Wavelength selector switch
US20130272650A1 (en) Wavelength cross connect device
JP5718016B2 (ja) 光操作装置
TW200401128A (en) Method and apparatus for integrating an optical transmit module
JPH11326851A (ja) プログラム可能な波長分割多重化追加／ドロップ装置
JP2002072157A (ja) 波長可変フィルター及び空間光スイッチ
WO2011090575A2 (en) Optical modulator using a dual output laser embedded in a mach zehnder interferometer
JP2004093787A (ja) 光スイッチ、光通信用装置及び光通信システム
JP4949355B2 (ja) 波長選択スイッチ
US6993217B2 (en) Optical switch device
JP2004078195A (ja) 導波路内を伝播する光信号の経路を変更する方法、光スイッチング装置、光信号を第１の導波路から第２の導波路に切り替える方法、光信号を導波路から送り出すシステム、及び三次元多層光スイッチ
WO2024066614A1 (zh) 光调制装置、波长选择开关和光通信设备
KR101165715B1 (ko) 광 스위치를 포함하는 광통신 소자
US7949217B2 (en) Selectively enhancing angular beam deflection
JP4776370B2 (ja) 光スイッチ及び光スイッチの製造方法
JP2014197154A (ja) 光操作装置
JPH0882711A (ja) 光合波器及び光分波器
US7209607B2 (en) Optical space-switching matrix
CN113985531B (zh) 波长选择开关及其温漂补偿方法
Sorimoto et al. Polarization insensitive wavelength selective switch using LCOSs and monolithically integrated multi-layered AWG
CA2264324A1 (en) Progammable demultiplexer using electro-optically modulated polyeric gragting array
CN117784463A (zh) 空间光调制器、光控制组件、光通信设备
JP4802175B2 (ja) 光信号処理装置
US20030133643A1 (en) Optical switch

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23869862

Country of ref document: EP

Kind code of ref document: A1