Classifications

• • 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
  • G02B6/29305—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 as bulk element, i.e. free space arrangement external to a light guide
  • G02B6/29313—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 as bulk element, i.e. free space arrangement external to a light guide characterised by means for controlling the position or direction of light incident to or leaving the diffractive element, e.g. for varying the wavelength response
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04Q—SELECTING
  • H04Q11/00—Selecting arrangements for multiplex systems
  • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
  • H04Q11/0005—Switch and router aspects
• • 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
  • G02B6/27—Optical coupling means with polarisation selective and adjusting means
  • G02B6/2753—Optical coupling means with polarisation selective and adjusting means characterised by their function or use, i.e. of the complete device
  • G02B6/2766—Manipulating the plane of polarisation from one input polarisation to another output polarisation, e.g. polarisation rotators, linear to circular polarisation converters
• • 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
  • G02B6/29305—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 as bulk element, i.e. free space arrangement external to a light guide
  • G02B6/2931—Diffractive element operating in reflection
• • 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
  • G02B6/351—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements
  • G02B6/3512—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements the optical element being reflective, e.g. mirror
• • 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
  • G02B6/354—Switching arrangements, i.e. number of input/output ports and interconnection types
  • G02B6/356—Switching arrangements, i.e. number of input/output ports and interconnection types in an optical cross-connect device, e.g. routing and switching aspects of interconnecting different paths propagating different wavelengths to (re)configure the various input and output links
• • 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
  • G02B6/3594—Characterised by additional functional means, e.g. means for variably attenuating or branching or means for switching differently polarized beams
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04Q—SELECTING
  • H04Q11/00—Selecting arrangements for multiplex systems
  • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
  • H04Q11/0005—Switch and router aspects
  • H04Q2011/0007—Construction
  • H04Q2011/0026—Construction using free space propagation (e.g. lenses, mirrors)
  • H04Q2011/003—Construction using free space propagation (e.g. lenses, mirrors) using switches based on microelectro-mechanical systems [MEMS]

Definitions

• the present invention relates to the field of optical communications, and in particular, to a wavelength selective switch. Background technique
• Wavelength Division Multiplexing (WDM) technology has been widely used in optical transmission networks at various levels. Its network topology also ranges from simple ring and tree structures to more complex networks. Evolution of the structure.
• IP Internet Protocol
• IPTV Internet Protocol Television
• NTN Next Generation Network
• 3G third-generation mobile communication technologies
• ROADMs Reconfigurable Add/Drop multiplexers
• ROADM nodes includes three main technologies: Wavelength Blocker (WB) technology, Planar light circuit (PLC) technology, and Wavelength selective switch (WSS) technology.
• WSS technology has a frequency bandwidth, low dispersion, and supports port-wavelength-independent (colorless, that is, each port can interface optical signals of any wavelength) and higher dimensions (the dimension here refers to the maximum ROADM node can provide)
• the number of connections is, and is highly regarded by device manufacturers as the mainstream technology for implementing ROADM.
• Figure 1 shows a lxN WSS structure diagram using Micro Electro Mechanical Systems (MEMS) technology as an example.
• MEMS Micro Electro Mechanical Systems
• the grating is equivalent to a light multiplexing and demultiplexer
• the switching engine is equivalent to a light switching switch that can perform optical path selection.
• N x M WSS N input fiber ports, M output fiber ports
• multiple and multiple layers of optical switch structures are usually required, but The reflection of light on such structures is not ideal due to the presence of phenomena such as dispersion, that is, a portion of the light may be reflected to the unwanted exit port.
• dispersion is most likely to form in-band crosstalk at corresponding positions of adjacent layers, that is, crosstalk formed by erroneously reflecting light of the same wavelength to the same exit port. Since it cannot be separated from the normal signal (because the crosstalk signal has the same wavelength), it will have a serious impact on signal transmission. Summary of the invention
• Embodiments of the present invention provide a wavelength selective switch that can suppress crosstalk in a wavelength selective switch of N X M (N input fiber ports, M output fiber ports; or M input fiber ports, N output fiber ports).
• an embodiment of the present invention provides a wavelength selection switch, including:
• At least two input fiber ports for respectively inputting optical signals from at least two input fibers; a polarity control unit for adjusting polarity of an optical signal input from each input fiber port, so that at least two channels are adjusted
• the optical signals are all optical signals having only one polarity, and the adjusted at least two optical signals have the same polarity; at least two optical signals respectively obtain at least two sets of optical signals having multiple wavelengths;
• a reflective element configured to reflect the at least two sets of optical signals having multiple wavelengths to at least two reflective areas on the switch engine
• a polarizer disposed between the reflective element and the switching engine and covering the at least two reflective regions of the switching engine for performing optical signals passing therethrough according to polarity of the polarity control unit Filter
• a polarity rotating unit located between the polarizer and the switching engine and covering a first reflective area of the at least two reflective areas of the switching engine without covering adjacent to the first reflective area a reflective area for rotating the polarity of the optical signal passing therethrough by 90 degrees;
• the switching engine wherein the switching engine includes at least two reflective regions, each reflective region of the switching engine performs reflective control of an optical signal incident on the reflective region to reflect it toward the reflective component, such that The reflected control optical signal is output through the corresponding output fiber port.
• the embodiment of the present invention further provides another wavelength selection switch, including:
• At least two input fiber ports for respectively inputting optical signals from at least two input fibers; a polarity control unit for adjusting a polarity of the optical signal input from each input fiber port, so that at least the adjusted The two optical signals respectively become optical signals having a single polarity, and the adjusted adjacent two optical signals have a polarity difference of 90 degrees; at least two optical signals respectively obtain at least two sets of multiple wavelengths.
• a reflective element configured to reflect the at least two sets of optical signals having multiple wavelengths to at least two reflective areas on the switch engine
• At least two polarizers disposed between the reflective element and the switching engine and respectively covering the at least two reflective regions of the switching engine for respectively adjusting at least two according to the polarity control unit The polarity of the road light signal, filtering the optical signal passing through it;
• each reflective region of the switching engine performs reflective control of an optical signal incident on the reflective region to reflect it toward the reflective component, such that The reflected control optical signal is output through the corresponding output fiber port.
• an embodiment of the present invention further provides a wavelength selection switch, including:
• N fiber input ports for inputting optical signals from N input fibers
• N 1 XM/2 beamsplitters whose inputs are respectively connected to the N fiber input ports; each 1 x M/2 beam splitter is used to split the input optical signal into M/2 optical signals, wherein, N and M is an integer greater than or equal to 2;
• N X 2 wavelength selective switches having crosstalk suppression function, wherein N input ports of each of the N X 2 wavelength selective switches are connected to one output of all of the N optical splitters;
• the ⁇ 2 wavelength selective switch is any one of the wavelength selection switches described above, and the optical fiber input port of the NX 2 wavelength selective switch corresponds to the optical fiber output port of the wavelength selective switch as described above, the NX 2 The fiber output port of the wavelength selective switch corresponds to the fiber input port of the wavelength selective switch as described above.
• the polarity of the optical signal input by different input optical fibers is controlled, thereby suppressing Crosstalk.
• One of the control methods is to add a polarity control unit, a polarizer and a polarity rotation unit to the wavelength selection switch, and the polarity control unit adjusts the input light signal to an optical signal having the same polarity, due to the polarizer
• the polarity filtering action and the 90 degree polarity rotation of the polarity rotation unit when the optical signal reflected by the switching engine crosstalks, the crosstalk light signal cannot pass through the polarity rotation unit twice, so that the polarity of the crosstalk light signal is
• the polarity of the polarizer is different by 90 degrees, so the crosstalk optical signal cannot pass through the polarizer, thereby achieving the purpose of suppressing the crosstalk optical signal;
• the other control method is to add the polarity control unit and the polarizer to the wavelength selective switch.
• the polarity control unit adjusts the input different light signals to optical signals having a single polarity and different polarities of the light signals of 90 degrees, and is filtered by a plurality of polarizers having corresponding polarities, when the switching engine reflects
• the polarity of the crosstalk optical signal is 90 degrees different from the polarity of the polarizer on the optical path, so the crosstalk optical signal cannot pass the polarization.
• the complexity of the system structure is not significantly increased, and crosstalk can be suppressed in the constructed wavelength selective switch of the ⁇ ⁇ .
• FIG. 1 is a schematic structural view of a conventional 1 X N wavelength selective switch using MEMS technology
• FIG. 2 is a schematic structural view of a conventional N x M WSS
• FIG. 3 is a schematic diagram of a specific composition of a wavelength selective switch in an embodiment of the present invention.
• FIG. 4 is a schematic diagram of another specific composition of the wavelength selective switch in the embodiment of the present invention.
• FIG. 5 is a schematic diagram of a specific composition of the polarity control unit in the embodiment of the present invention.
• FIG. 6 is a schematic diagram of another specific composition of a polarity control unit in an embodiment of the present invention
• FIG. 7 is a schematic diagram of a specific composition of a 2 X N wavelength selective switch having a calibrator according to an embodiment of the present invention
• FIG. 8 is a schematic diagram of a specific composition of an MXN wavelength selective switch in an embodiment of the present invention.
• the NXM wavelength selective switch is constructed by cascading multiple NX 1 wavelength selective switches, the crosstalk effect of the conventional M x N wavelength selective switch structure can be avoided. As shown in FIG.
• NXM N inputs, M outputs
• NX 1 wavelength selective switches N inputs, M outputs
• a scheme for suppressing crosstalk by adjusting the polarity of an optical signal based on the structure of the existing N x l wavelength selective switch is proposed. That is, the input optical signals of different paths have different polarities when incident on the switching engine, and then the crosstalk between different road lights can be suppressed by filtering the polarity of the optical signals reflected by the switching engine (although from The crosstalk signal of the other light is the same as the wavelength of the local optical signal, but the polarity is different, so crosstalk can be suppressed by polarity.
• the optical signal input or output is not a single-polarity signal, in order to achieve the above-mentioned purpose of suppressing crosstalk by polarity, on the input side, it is necessary to adjust the polarity of the optical signal in advance so that the light incident on the switching engine is made.
• the signal is a single-polar signal; on the output side, it is necessary to restore a single-polar optical signal to a non-unipolar signal.
• the wavelength selection switch in the embodiment of the present invention is illustrated by taking an example of two input fiber ports in the example of FIG. 3, which includes:
• At least two input fiber ports 10, 12 are used to input optical signals from at least two input fibers, respectively. Only two input fiber ports are illustrated in the illustration, and in other embodiments of the invention, a third or even more input fiber ports may be further included.
• the polarity control unit 20 is configured to adjust the polarity of the optical signal input from the input fiber ports 10, 12 such that the adjusted at least two optical signals become optical signals having only one polarity.
• the polarity of the adjusted at least two optical signals may be different polarities or the same polarity; preferably, It can be designed to adjust the signals of different optical fibers to signals with the same polarity to simplify the overall structure of the system.
• the light from the input fiber port 10 is first decomposed into two orthogonal sub-polar lights in the polarity control unit, and then the polarity of one of the lights is rotated to the polarity of the other light, so that two The road light has the same polarity, forming an optical signal having only one polarity.
• the polarity control unit can One polarity will be rotated to a direction perpendicular to the polarity of the other path, and then the two sub-lights will be combined to form a light of the same polarity as the incident light.
• the two-way sub-light can be two parallel beams on the optical path, and the two parallel beams have a certain distance between them, and in the subsequent optical path, the two beams are parallelized.
• the optical signals having the same polarity can be processed; that is, the two mutually identical sub-lights can be distinguished by the relative positions on the optical path space.
• the two-way sub-light is combined into one optical signal having a polarity consistent with the polarity of the incident light, the information carried by the polarity of the optical signal can still be restored.
• at least two sets of optical signals having a plurality of wavelengths are respectively obtained.
• the upper half of the diffractive grating decomposes light from the input fiber port 10
• the lower half of the diffraction grating decomposes light from the input fiber port 12.
• the third region may be further included, and the third region is adjacent to the second region and not adjacent to the first region; and the polarity of the optical signal input to the third region may be The optical signals of a region have the same polarity.
• the reflective element 40 is configured to reflect the at least two sets of optical signals having a plurality of wavelengths to at least two reflective regions on the switch engine.
• a polarizer 50 located between the reflective element and the switching engine and covering the at least two reflective regions of the switching engine for optical signals passing therethrough according to the polarity of the polarity control unit Filter.
• a polarity rotating unit 52 located between the polarizer and the switching engine and covering a first reflective area of the at least two reflective areas of the switching engine without covering the first reflective area An adjacent reflective area for rotating the polarity of the optical signal passing therethrough by 90 degrees.
• the polarity rotating unit can adopt an existing optical device having a polarity rotation function, such as a Faraday rotating mirror, a quarter-slide, or the like. In the example of Figure 3, the polar rotation unit only blocks the reflective area on the underside of the switching engine.
• the switching engine 60 includes at least two reflective regions. Each reflective area of the switching engine 60 The optical signal incident on the reflective area is reflected and reflected to the reflective element such that the reflected-controlled optical signal is output through the corresponding output fiber port.
• the at least two reflective areas of the switch engine 60 may be at least two areas that are spatially up and down or left and right adjacent. The figure shows only two areas, the upper and lower rows in the figure.
• the switching engine when the wavelength selective switch further includes a third optical fiber input port, when the third optical signal is input, the switching engine further includes a third area, configured to reflect the third optical signal. group.
• the switching engine in the embodiment of the present invention may be a switching engine using MEMS technology, and an array of a small number of mirrors controls the reflection angle of light by controlling the rotation of the micro mirror.
• MEMS technology MEMS technology
• other types of switching engines are also possible, and no limitation is imposed here.
• the optical path in the wavelength selective switch of the embodiment of the present invention is exemplified by a wavelength selective switch having two input fiber ports (10, 12) (where the polarity rotating unit 52 covers only the second reflective area of the switching engine). Briefly describe.
• the working optical path in the wavelength selection switch is:
• the optical signal input from the input fiber port 10 (for convenience of description, the optical signal input from the input fiber port 10 is referred to as a first optical signal) is incident on the diffraction grating 30 after being processed by the polarity control unit 20.
• a first diffraction region, at a first diffraction region of the diffraction grating 30 (such as the upper half of the diffraction grating as shown in FIG.
• the optical signals of one wavelength are referred to as a first plurality of optical signals of a plurality of wavelengths; the first plurality of optical signals of the plurality of wavelengths are directed toward the reflective element 40 and are reflected by the reflective element 40 toward the first reflective area of the switching engine 60. Since the polarity rotation unit 52 covers only the second reflection area of the light-emitting engine 60, and the polarizer 50 covers the two reflection areas of the switching engine 60, the first set of optical signals of a plurality of wavelengths are reflected by the reflection element 40.
• the first reflection area of the switching engine 60 can be used for the first plurality of wavelengths of light
• the optical signal of each wavelength in the number is separately subjected to reflection control (ie, controlling the direction of reflection of the optical signal of each wavelength), and the optical signal of each of the first set of optical signals of the plurality of wavelengths is switched by the switching engine 60 a reflective area is reflected and then passed through the polarizer 50, the reflective element 40, the diffraction grating 30, and the polarity control unit 20, and then output from the corresponding output fiber port of the wavelength selective switch;
• the optical signal input from the input fiber port 12 (for convenience of description, the optical signal input from the fiber input port 12 is referred to as a second optical signal) is incident on the diffraction grating 30 after being processed by the polarity control unit 20.
• a second diffraction region at the second diffraction region of the diffraction grating 30 (as shown in FIG.
• the lower half of the grating is decomposed into a set of optical signals of a plurality of wavelengths (for convenience of description, the optical signals of the plurality of wavelengths are referred to as a second plurality of optical signals of a plurality of wavelengths);
• the wavelength light signal is directed toward the reflective element 40 and is reflected by the reflective element 40 toward the second reflective area of the switching engine 60; since the polarizer 50 covers the two reflective areas of the switching engine 60, and the polarity rotating unit 52 covers The second reflective area of the light-emitting engine 60, after the second set of optical signals of the plurality of wavelengths are reflected by the reflective element 40, passes through the polarizer 50, passes through the polar rotating unit 52, and then reaches the second reflective area of the switching engine 60.
• the second reflective area of the switching engine 60 can separately perform reflection control on the optical signals of each of the second plurality of wavelengths of optical signals (ie, control the direction of reflection of the optical signals of each wavelength), the second group
• the optical signal of each of the wavelengths of the optical signal is reflected by the second reflective area of the switching engine 60 and then sequentially passes through the polar rotating unit 52, the polarizer 50, the reflective element 40, the diffraction grating 30, and the pole.
• the control unit 20 is then output from the corresponding fiber output port of the wavelength selective switch.
• the first set of optical signals of a plurality of wavelengths are incident from the reflective element 40 to the first reflective area of the switching engine 60 and from the first reflective area of the switching engine 60.
• the polarity rotation unit 52 is not passed during the incident to the reflective element 4, and therefore, the polarity of the first plurality of wavelengths of the optical signal emitted from the analyzer 50 to the first reflection region of the switching engine 60 is checked.
• the polarity of the first plurality of wavelengths of optical signals reflected by the first reflective area of the switching engine 60 received by the polarizer 50 is the same, thereby being the first plurality of wavelengths of the first reflective area of the switching engine 60
• the light signal can pass through the polarizer 50 again.
• the second set of optical signals of a plurality of wavelengths are required to be incident from the reflective element 40 to the second reflective region of the switching engine 60 and from the second reflective region of the switching engine 60 to the reflective element 4.
• the polar rotation unit 52 After passing through the polarity rotation unit 52, that is, the second group of optical signals of a plurality of wavelengths are emitted from the polarizer 50 to be incident on the polarizer 50 again, the polar rotation unit 52 is passed twice;
• the polarity of the second group of optical signals of the plurality of wavelengths is rotated 90 degrees once every time the polarity rotating unit 52 is passed, that is, it is incident again.
• the polarity of the second plurality of wavelengths of the optical signal of the polarizer 50 is rotated by 0 or 180 degrees with respect to the polarity of the second plurality of wavelengths of the optical signal emitted from the polarizer 50; If the polarity is rotated by 0 degrees or 180 degrees, the polarity of the optical signal is not changed. Therefore, the polarity of the second plurality of wavelengths of the optical signal incident on the polarizer 50 again is emitted from the polarizer 50.
• the second group of optical signals with multiple wavelengths Same polarity, the above-described re-enter into the second optical signals from the plurality of wavelengths polarizer 50 can also polarizer 50 again.
• the first reflective area and/or the second reflective area of the switching engine 60 are in progress.
• a portion of the optical signals of the first plurality of wavelengths of the optical signals are erroneously reflected toward the polar rotation unit 52 and/or the second plurality of wavelengths due to control errors or other reasons.
• the partial wavelength optical signal in the optical signal is erroneously reflected and is directly incident on the polarizer 50 without passing through the polar rotation unit 52. Due to such erroneous reflection, the first portion incident to the polarizer 50 (for convenience of description, the portion of the analyzer 50 that covers the first reflective region of the switching engine 60 is referred to as the first portion) is in the optical signal.
• An optical signal comprising both a first plurality of wavelengths and a partial wavelength of the second plurality of wavelengths, and/or a second portion incident on the polarizer 50 (for convenience of description,
• the optical signal of the portion of the polarizer 50 that covers the second reflective region of the switching engine 60 is referred to as the second portion.
• the optical signal includes a second plurality of optical signals and a first plurality of wavelengths. Part of the wavelength of the optical signal in the signal, this phenomenon is called crosstalk.
• a portion of the wavelength optical signals of the second plurality of wavelengths of light signals incident on the first portion of the polarizer 50 are emitted from the polarizer 50 to be incident on the polarizer 50 again.
• the polarity of the partial wavelength optical signal in the second group of multiple wavelength optical signals is only rotated by 90 degrees, that is, incident on the polarizer 50
• the polarity of the portion of the wavelength optical signals of a portion of the second plurality of wavelengths of optical signals is perpendicular (or orthogonal) to the polarity of the output from the polarizer 50 to the switching engine 60.
• the polarity of the partial wavelength optical signal of the first plurality of wavelengths of the optical signal incident on the second portion of the polarizer 50 is perpendicular to the polarity when it is emitted from the polarizer 50 to the switching engine 60. (or called orthogonal).
• the polarizer 50 does not allow an optical signal whose polarity is perpendicular to the polarity of the polarizer 50 to pass, allowing the optical signal having the same polarity as that of the polarizer 50 to pass completely, and thus, in the embodiment of the present invention
• the optical signal emitted from the first portion of the polarizer 50 toward the reflective element includes only the first plurality of optical signals of the plurality of wavelengths, and the optical signal emitted from the second portion of the polarizer 50 toward the reflective element. Only the second set of optical signals of multiple wavelengths is included, that is, crosstalk is suppressed.
• the polarity control unit controls the polarity of the output optical signal, so that the optical signals of different paths incident on the polarizer are adjusted to signals having different polarities, for example, for two optical fibers, adjusted to have a polarity difference of 90 degrees.
• the signal because of the different polarities of the polarizers passing through different optical signals, can achieve polarity filtering when crosstalk occurs. That is, the wavelength selection switch includes:
• the polarity control unit 22 is configured to adjust the polarity of the optical signal input from the input fiber ports 10, 12, so that the adjusted at least two optical signals respectively become optical signals having a single polarity, and the adjusted phase
• the polarities between the adjacent two paths are 90 degrees apart; at least two subsequent optical signals respectively obtain at least two sets of optical signals having a plurality of wavelengths;
• a reflective element 40 configured to reflect the at least two sets of optical signals having multiple wavelengths to at least two reflective areas on the switch engine
• At least two polarizers 500, 502 between the reflective element and the switching engine and respectively covering the at least two reflective regions of the switching engine for respectively adjusting according to the polarity control unit The polarity of at least two optical signals, filtering the optical signals passing therethrough;
• the switching engine 60 wherein the switching engine includes at least two reflective regions, and each of the reflective regions of the switch arch reflects reflection of an optical signal incident on the reflective region to reflect the reflective component , the optical signal after the reflection control is output through the corresponding output fiber port.
• the polarity control unit that is, the polarity of the input different light signals is controlled differently, so that the output light is a single-polar light, but at the same time different
• the polarity of the output light of the road is 90 degrees out of order.
• the polarizer corresponding to different road light signals has the same polarity as the light outputted by the polarity control unit, and the light signal reflected by the reflection engine still passes through the same polarizer.
• the optical signal reflected by the reflection engine crosstalks, since the polarity of the crosstalk optical signal is different from the polarity of the polarizer, the polarity cannot be passed and thus filtered.
• the following is a pole with an optical signal having two input fiber ports (10, 12) and two polarizers (the polarizer 500, the polarizer 502, respectively, and the two polarizers respectively allow complete passage)
• the wavelength selection switch of the difference of 90 degrees is taken as an example, and the optical path in the wavelength selective switch of the embodiment of the present invention is briefly described.
• the working optical path in the wavelength selection switch is:
• the optical signal input from the optical fiber input port 10 (for convenience of description, the optical signal input from the input optical fiber port 10 is referred to as a first optical signal) is processed by the polarity control unit 22 to become the first
• the polar optical signal is incident on the first diffraction region of the diffraction grating 30, and is split into a plurality of optical signals of a plurality of wavelengths at the first diffraction region of the diffraction grating 30 (for convenience of description, the optical signals of the plurality of wavelengths are set.
• the first set of optical signals of the plurality of wavelengths are directed toward the reflective element 40 and are reflected by the reflective element 40 toward the first reflective area of the switching engine 60; 500 Covering the first reflective area of the switch engine 60, after the first set of optical signals of the plurality of wavelengths are reflected by the reflective element 40, only the polarizer 500 is passed (only the optical signal having the polarity of the first polarity can completely pass the polarizing And passing through the polarizer 502 and then reaching the first reflective area of the switching engine 60; the first reflective area of the switching engine 60 can separately perform optical signals for each of the first plurality of wavelengths of optical signals Reflection control (ie, controlling the direction of reflection of the optical signal of each wavelength), the optical signal of each of the first set of optical signals of the plurality of wavelengths is reflected by the first reflective area of the switching engine 60 and then sequentially passes through the polarizer 500, the reflective element 40, the diffraction grating 30, and the
• the optical signal input from the optical fiber input port 12 (for convenience of description, the optical signal input from the optical fiber input port 12 is referred to as a second optical signal) is converted into a second by the processing of the polarity control unit 22.
• An optical signal having a polarity (90 degrees out of phase with the first polarity) is incident on the second diffraction region of the diffraction grating 30, and is split into a plurality of optical signals of a plurality of wavelengths at the second diffraction region of the diffraction grating 30 (for convenience of description)
• the set of optical signals of a plurality of wavelengths is referred to as a second set of optical signals of a plurality of wavelengths; and the second set of optical signals of the plurality of wavelengths are directed toward the reflective element 40 and are directed toward the switching engine 60 by the reflective element 40 Directional reflection of the two reflective regions; the polarizer 502 (only the optical signal of the second polarity can pass completely through the polarizer) covers only the second reflective
• the second reflective area of the switching engine 60 can be used for each of the second plurality of wavelengths of the optical signal.
• the optical signals are separately subjected to reflection control (ie, controlling the direction of reflection of the optical signals of each wavelength), and the optical signals of each of the second plurality of optical signals of the plurality of wavelengths are reflected by the second reflective area of the switching engine 60.
• reflection control ie, controlling the direction of reflection of the optical signals of each wavelength
• the optical signals of each of the second plurality of optical signals of the plurality of wavelengths are reflected by the second reflective area of the switching engine 60.
• the output After passing through the polarizer 502, the reflective element 40, the diffraction grating 30, and the polarity control unit 20, the output is output from the corresponding fiber output port of the wavelength selective switch.
• the first set of optical signals of a plurality of wavelengths are incident from the reflective element 40 to the first reflective area of the switching engine 60 and from the first reflective area of the switching engine 60.
• the polarity of the first plurality of wavelengths of the optical signal emitted from the analyzer 50 to the first reflective region of the switching engine 60, and the switching engine 60 received by the polarizer 500 The polarities of the first plurality of wavelengths of the optical signals reflected by the first reflective area are all the first polarity, so that the first plurality of wavelengths of the optical signals of the first reflective area of the switching engine 60 can pass again.
• the polarizer 500 is the process of entering the reflective element 4, the polarity of the first plurality of wavelengths of the optical signal emitted from the analyzer 50 to the first reflective region of the switching engine 60, and the switching engine 60 received by the polarizer 500.
• a second plurality of wavelengths of optical signals are incident from the reflective element 40 to the second reflective region of the switching engine 60 and from the second reflective region of the switching engine 60 to the reflective element 4.
• the polarity of the second plurality of wavelengths of the optical signal emitted from the analyzer 50 to the second reflection region of the switching engine 60, and the second reflection region of the switching engine 60 received by the polarizer 502
• the polarities of the reflected second plurality of wavelengths of optical signals are all of a second polarity such that the second plurality of wavelengths of optical signals of the second reflective region of the switching engine 60 can again pass through the polarizer 502.
• the first reflective area and/or the second reflective area of the switching engine 60 when performing reflection control, causes partial wavelengths of the first plurality of wavelengths of optical signals due to control errors or other reasons.
• the optical signal which is erroneously reflected to the polarizer 502 and/or a portion of the second set of optical signals of the plurality of wavelengths, is erroneously reflected toward the polarizer 500.
• the optical signal incident on the polarizer 500 includes both the first group of optical signals of the plurality of wavelengths and the optical signals of the partial wavelengths of the second plurality of optical signals of the plurality of wavelengths, and And the optical signal incident on the polarizer 502 includes both the second plurality of optical signals of the plurality of wavelengths and the optical signals of the partial wavelengths of the optical signals of the first plurality of wavelengths.
• This phenomenon is called crosstalk. .
• the polarity of the second plurality of wavelengths of the optical signals incident on the polarizer 500 is the second polarity, and the polarizer 500 only allows the optical signals of the first polarity to pass completely, The optical signal of the second polarity orthogonal to the first polarity just does not pass completely.
• the polarity of the first plurality of wavelengths of the optical signal incident on the polarizer 502 is the first polarity, and the polarizer 502 only allows the optical signal of the second polarity to pass completely, with the second pole.
• the optical signal of the first polarity that is orthogonal is just not able to pass completely. That is, crosstalk is suppressed.
• the switching engine and the diffraction grating respectively include a corresponding number of reflection regions and diffraction intervals; meanwhile, each reflection region is only two front and rear The regions are adjacent, but are not adjacent to other regions, and are in a plurality of rows or columns; the diffraction interval can also be set in the same manner, and the diffraction region of the diffraction grating is also consistent with the arrangement of the reflection region of the switching engine; In an embodiment with a polar rotating unit, the polar rotating unit covers only the singular or even area of the switching engine, ie in the form of a spaced coverage.
• the reflective area of the switching engine includes a spatially adjacent first reflective area, a second reflective area 2x or (2x+1) reflective area, and X is a natural number greater than or equal to 1.
• the polarity rotation unit includes a plurality of discontinuous plurality of polarity rotators, the plurality of polarity rotators sequentially covering the first reflection area of the switching engine, the second reflection area 2x+1 reflection area, or The second reflection area is a 2x reflection area.
• the diffraction region of the diffraction grating and the reflection region of the switching engine are The foregoing embodiment is identically arranged; it differs from FIG. 3 in that it does not have a polarity rotating unit, but is rotated by a polarity control unit, and a polarizer unit having a plurality of polarities sequentially different by 90 degrees corresponds to The diffraction area is arranged.
• a polarity rotating unit but is rotated by a polarity control unit
• a polarizer unit having a plurality of polarities sequentially different by 90 degrees corresponds to The diffraction area is arranged.
• the polarity control unit 20 may include: a polarity decomposition module 200, configured to decompose the input optical signal into a first polarity signal and a second polarity signal, The polarity of the first polarity signal is orthogonal to the polarity of the second polarity signal; the first polarity rotation module 202 is configured to rotate the polarity of the first polarity signal by 90 degrees to make the pole And synthesizing the polarity of the second polarity signal, and synthesizing the rotated signal and the second polarity signal to obtain an optical signal having only the second polarity; wherein the second polarity signal is The polarity is the polarity of the polarity control unit.
• a polarity decomposition module 200 configured to decompose the input optical signal into a first polarity signal and a second polarity signal, The polarity of the first polarity signal is orthogonal to the polarity of the second polarity signal
• the polarity control unit 22 may include: a polarity decomposition module 200, configured to decompose the input at least two optical signals into a first polarity signal and a first a polarity of the first polarity signal is orthogonal to a polarity of the second polarity signal; and a second polarity rotation module 203 is configured to correspond to the second two adjacent optical signals
• the polarity of the first polarity signal of one optical signal is rotated by 90 degrees to have the same polarity as the polarity of the second polarity signal corresponding to the first optical signal, and the rotated signal corresponds to the Combining a second polarity signal of the first optical signal to obtain an optical signal having only the second polarity; and also for using a second polarity corresponding to the second optical signal of the adjacent two optical signals
• the polarity of the signal is rotated by 90 degrees so that its polarity is the same as the polarity of the first polarity signal
• optical devices having corresponding functions may be used.
• the polar decomposition module may be implemented by a polar beam splitter, and at the same time, based on the reversibility of light, the polarity may also be realized.
• the function of the synthesis module; likewise, the polarity rotation module can also be implemented by an optical device that implements the functions of the aforementioned polarity rotation unit.
• the polarity control unit 20 or the polarity control unit 22 may further include: a polarity synthesis module (not shown) for converting the optical signals input to the polarity control unit after the switch engine is reflected It is a non-unipolar optical signal and is output through the output fiber port.
• a polarity synthesis module (not shown) for converting the optical signals input to the polarity control unit after the switch engine is reflected It is a non-unipolar optical signal and is output through the output fiber port.
• the polarity control unit may not include the polarity decomposition module and the first polarity rotation module (or the second polarity rotation module), and the polarity control unit Just do the role of polarity filtering. If the output optical signal does not need to be a non-unipolar signal, the polarity control unit in this example may not include the polarity synthesis module.
• the wavelength selective switch in the embodiment of the present invention may further include a calibrator 22; the calibrator 22 is located at the output fiber port and Between the polarity control units, the optical signal reflected by the switch engine is calibrated and output to the output fiber port.
• the calibrator 22 is further included on the basis of the embodiment shown in FIG.
• the above-mentioned wavelength selective switch may be a 2-input N output (when having two fiber input ports), and the above-mentioned wavelength selective switch may also be reversely used due to the optical path reversible principle, that is, an input port in forward use.
• the output port for reverse use As an output port for reverse use, the output port for forward use is used as an input port for reverse use, and the structure of the wavelength selective switch does not change.
• FIG. 7 is a schematic diagram of a specific structure of a 2 ⁇ N WSS in an embodiment of the present invention.
• the WSS consists of: two input fiber ports (10 and 12), N fiber output ports (example only in the figure), calibrator, polarity control unit, diffraction grating, mirror, crosstalk suppression unit (including a bias) , a polar rotating unit), a switching engine with two separate zones.
• the input light first enters the polarity control unit.
• the polarity control unit the light from different input fibers is decomposed into two polarities of orthogonal polarity, and then one of the polarities is rotated to the other polarity.
• the output light is only one polarity, and the optical signal of the polarity is an optical signal that can completely pass through the polarizer on the subsequent optical path.
• the light from the input fiber 1 is first decomposed into two orthogonal light beams of orthogonal polarity in the polarity control unit, and then the polarity of one of the lights is rotated to the polarity of the other light, so that the two paths of light Have the same polarity (this kind of processing is mainly because the existing polar multiplex transmission system makes a signal with two polarities usually on one light, and the processing of this scheme is based on a single polarity), In the subsequent optical path processing, the two sub-beams are treated as a whole, until the light is reflected and then passed through the polarity control unit again. At this time, one of the two paths of light is rotated to be different from the polarity of the other path.
• the two-way sub-synthesis is combined into one light with two polarities (in order to support the requirements of the polar multiplexing system).
• the distinction between two sub-lights of the same polarity is achieved by the relative position between them.
• the upper half of the diffraction grating decomposes light from the input fiber port 10
• the lower half of the diffraction grating decomposes light from the input fiber port 12.
• the corresponding diffraction grating can be divided into upper, middle and lower regions; when there are more input light signals, the diffraction grating is further divided into multiple rows ( Or a multi-column area.
• the decomposed light is reflected by the mirror onto the polarity suppression unit, which consists of a polarizer and a polar rotation unit.
• the polarity suppression unit which consists of a polarizer and a polar rotation unit.
• Light from the input fiber port 10 is reflected to the upper half of the polarizer in the polarity suppression unit, and light from the input fiber port 12 is reflected to the lower half of the polarizer in the polarity suppression unit.
• the function of the polarizer is to allow only light of a particular polarity to pass completely, while completely blocking light of a polarity orthogonal to that particular polarity.
• the optical signal having a single polarity that the polarity control unit outputs to the diffraction grating can pass completely through the polarizer.
• the polarizer covers the input light and the output light path of the entire switching engine, and the polar rotating unit placed behind the polarizer covers only the lower half of the polarizer and the lower half of the switching engine.
• the signal from the input fiber port 10 passes through the upper half of the polarizer and is directly reflected by the upper half of the switching engine and is reflected back to the upper half of the polarizer without passing through only the polarizer and the lower half of the switching engine.
• the polar rotating unit the reflected light passes through the polarizer again, since the signal originating from the input fiber port 10 is only processed in the upper half of the polarizer and the switching engine, so it does not pass through the polar rotating unit, that is, the pole of light.
• the sex is not changed, so the reflected light can be emitted through the polarizer.
• the polarity is first changed by the polarity rotation unit (the polarity is rotated by 90 degrees, perpendicular to the polarity of the polarizer, so that this polarity cannot pass.
• the polarizer is then reflected by the lower half of the switching engine.
• the reflected light passes through the polar rotating unit again, and the polarity is rotated again by 90 degrees.
• the result of the two rotations causes the polarity of the reflected light to return to the polarizer.
• the reflected light can pass through the lower half of the polarizer.
• the crosstalk light is the optical path from the input fiber port 10 that is erroneously reflected in the switching engine to the lower half of the area (the light does not pass through the polar rotating unit before entering the switching engine, and undergoes a polarity rotation when reflected).
• Polarity rotation unit Since such light passes only once through the polarity rotator, the polarity is only rotated by 90 degrees, so that the polarity of the light signal is just output to the diffraction by the polarity control unit
• the polarity of the optical signal of the grating is 90 degrees apart, so it can not pass through when it is reflected to the polarizer, and is filtered out, that is, the purpose of suppressing crosstalk is achieved.
• the switching engine is divided into two separate upper and lower areas, and the light from the input fiber port 1 and the input fiber port 2 is separately reflected and controlled.
• the corresponding switching engine is divided into upper, middle and lower regions; meanwhile, the polarity rotating unit covers only the middle region in the upper, middle and lower regions (or up and down region).
• the switching engine is further divided into multiple rows (or columns), and the polar rotation unit covers an area interlaced.
• the polarity change in the embodiment of the present invention is mainly for the 90 degree change of the polarity after the light passes through the polar rotation unit, and the polarity of the backlight after switching the engine does not change by the polarizer.
• the passing device For light from the input fiber port 10, after passing through the mirror to the polarizer, the passing device includes the upper half of the diffraction grating, the upper half of the polarizer, and the upper half of the switching engine. There is no polarity rotation unit that changes polarity, so the polarity does not change. Since the light originating from the input fiber port 12 passes through the polarity rotation unit twice, its polarity changes by 180 degrees, and it does not change, and it can pass through the polarizer again.
• another wavelength selective switch in the embodiment of the present invention includes: N optical fiber input ports for correspondingly inputting optical signals from N input fibers; N 1 XM/2 splitting The input ends are respectively connected to the N optical fiber input ports, and are used for respectively dividing N optical signals input through the N optical fiber input ports into M/2 optical signals, where N and M are greater than or equal to 2 Integer; W2 NX 2 wavelength selective switches with crosstalk suppression function, the input of each of the NX 2 wavelength selective switches is connected to one output of all of the N optical splitters.
• the ⁇ 2 wavelength selective switch is a wavelength selective switch in the foregoing embodiment (as shown in FIG. 3, FIG. 4 or FIG. 7 and the like), and the optical fiber input port of the ⁇ 2 wavelength selective switch
• the optical fiber output port of the NX 2 wavelength selective switch corresponds to the two optical fiber input ports of the wavelength selective switch in the previous embodiment.
• the reverse use of the 2 XN wavelength selective switch shown in FIG. 7 becomes the NX 2 wavelength selective switch in this embodiment, that is, two input optical ports of the 2 ⁇ ⁇ wavelength selective switches shown in FIG.
• N output fiber ports of the 2 ⁇ ⁇ wavelength selective switches shown in Figure ⁇ serve as N input fiber ports in this embodiment.
• Wavelength selection switch In the example of Fig. 8, N ellipses represent N beamsplitters, the function of which is that one input signal is divided into exactly the same M/2 copies.
• 2 XN WSS can be used in reverse. You can use 2 as an input port, N as an output port, or N as an input port and 2 as an output port.
• ⁇ ⁇ M WSS works by outputting any wavelength signal from any input port to any one of the output ports.
• each channel's signal can reach each N X 2 WSS through a splitter.
• This WSS can select any one of the N input ports to send to any of the two input ports.
• the equivalent of N X M WSS can be achieved by a combination of such structures in the M/2 group. Output any wavelength signal of any input port to any one of the output ports.
• this embodiment Compared with the prior art method for constructing NXM WSS using NX 1 WSS, this embodiment only needs M/2 NX 2 WSS modules to implement NXM WSS, and the number of modules is reduced by 50% compared with the prior art.
• the number of fibers is ⁇ ( ⁇ /2), which is also reduced by 50%.
• i can also choose to be a number greater than or equal to 2, and use N xi WSS to construct N x M WSS.
• M/i WS i WSS modules are needed to implement NXM WSS.
• the number of modules is only in the prior art.
• the number of modules is 1/i, and the number of interconnected fibers is Nx (M/i), which is also only l/i in the prior art.
• the structure of the i N WSS is realized on the basis of the single WSS structure (i is a natural number greater than or equal to 2), and independent control is realized for the multi-path light.
• the polarity of the light incident on different regions of the switching engine is controlled by the polarity control unit and the polarizer (or also including the polar rotation unit), and the reflected light is limited by the respective reflection paths according to the polarity thereof. , thereby reducing mutual in-band crosstalk between light from different input fibers.
• the N X M WSS constructing more port numbers by using the embodiment of the present invention is constructed with respect to the use of 1 X N WSS, the number of modules is relatively reduced, and the number of interconnected fibers is N x (M/i), which is also reduced.
• the storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

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• Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
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• 2012
  • 2012-06-12 WO PCT/CN2012/076768 patent/WO2013185287A1/fr not_active Ceased
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