WO2021000616A1 - Wavelength selective switch and related device - Google Patents

Abstract

Disclosed in an embodiment of the present invention is a wavelength selective switch, comprising: an input optical fiber collimation array comprising multiple input ports; a relay lens positioned between a first switching engine and a second switching engine; a first lens assembly comprising A lenses and a second lens assembly comprising B lenses, wherein each of A and B is a natural number greater than or equal to 2, the first lens assembly is connected to the first switching engine and the relay lens, the second lens assembly is connected to the relay lens and the second switching engine, and each of the first lens assembly and the second lens assembly comprises a lens having a curvature in a dispersion direction; and an output optical fiber collimation array comprising multiple output ports. Arrangement of two or more lens assemblies between switching engines reduces filtering costs of a wavelength selective switch, and increases the filtering bandwidth of the wavelength selective switch.

Description

Wavelength selective switch and related device

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office on June 29, 2019, the application number is 201910581369.9, and the invention title is "a wavelength selective switch and related devices", the entire content of which is incorporated into this application by reference in.

Technical field

This application relates to the field of optical communication technology, and in particular to a wavelength selective switch and related devices.

Background technique

With the rapid growth of video and cloud services, operators are particularly concerned about the flexibility of optical network construction, the reduction of optical network construction and operation and maintenance costs. There are more and more directional dimensions (or transmission paths) that network nodes need to cross-connect. Operators can use reconfigurable optical add-drop multiplexers (ROADM) to remotely and automatically perform dimensions. Switching, etc., to replace the previous method of manually downloading the site to replace the optical fiber connection, so as to meet the needs of network dynamic connection. In order to meet the high efficiency and flexibility requirements of high-speed optical communication networks, ROADM, as the core of network cross-connections, needs continuous development.

In the current ROADM node, the use of discrete devices is a common implementation form. Use multiple 1×N wavelength selective switches (wavelength selective switches, WSS) to interconnect to build nodes to realize the routing and switching selection of different signals. When the network traffic increases, it is necessary to increase the number of 1×N wavelength selective switches. Increase the ability of business exchange within the node. However, this requires a large increase in the number of module slots in the existing equipment in order to access multiple 1×N wavelength selective switches, which increases the cost of the equipment, and the cost will rise sharply with the expansion of the business volume.

Therefore, the N×M wavelength selective switch and the N×N wavelength selective switch are now proposed to improve the service exchange capability in the node while saving the number of wavelength selective switches, where N and M are different positive integers greater than 1. In the N×M wavelength selective switch and the N×N wavelength selective switch, two or more switching engines are required to focus the corresponding optical signal to the corresponding spatial position. However, the filtering effect of the switching engine degrades the signal quality every time the optical signal passes through the first-level switching engine. The effect of filtering is particularly obvious in the case of cascading multi-level switching engines, which will seriously reduce the channel quality.

Summary of the invention

The embodiments of the present application provide a wavelength selective switch and related devices. By arranging two or more lens groups between the switching engines, the lens group includes X lenses with curvature in the dispersion direction, where X is greater than or equal to The natural number of 2. The filtering cost of the wavelength selective switch is reduced, the filtering bandwidth of the wavelength selective switch is improved, and the channel quality is improved.

The embodiments of this application provide the following technical solutions:

In the first aspect, an embodiment of the present application provides a wavelength selective switch, including: an input fiber collimation array, a first switching engine, a relay lens, a first lens group, a second lens group, a second switching engine, and an output fiber collimator. Straight array; the input fiber collimation array includes N input ports, N is a natural number greater than 1; the first switching engine is connected to the input fiber collimation array; the relay lens is connected to the first switching engine and the second switching engine, and the relay The lens is located between the first exchange engine and the second exchange engine, the relay lens is a lens in the direction of the exchange optical path; the first lens group includes A lenses, the second lens group includes B lenses, and A is greater than or equal to 2 A natural number, B is a natural number greater than or equal to 2. The first lens group connects the first exchange engine and the relay lens, the second lens group connects the relay lens and the second exchange engine, and at least one of the first lens group and the second lens group It includes a lens with curvature in the dispersion direction; the output fiber collimation array includes M output ports, where M is a natural number greater than 1, and the output fiber collimation array is connected to the second switching engine.

In the embodiment of the present application, a first lens group and a second lens group are arranged between the two-stage switching engines in the wavelength selective switch. The first lens group and the second lens group at least include lenses with curvature in the dispersion direction, and the first lens The group includes A lenses with curvature in the dispersion direction, and the second lens group includes B lenses with curvature in the dispersion direction, where A is a natural number greater than or equal to 2 and B is a natural number greater than or equal to 2. The filtering cost of the wavelength selective switch is reduced, the filtering bandwidth of the wavelength selective switch is improved, and the channel quality is improved.

In a possible implementation of the first aspect, the sum of the distances between the lenses in the first lens group is equal to the sum of the focal lengths of the lenses in the first lens group; the lens closest to the relay lens in the first lens group is The distance between the relay lenses is equal to the focal length of the lens; the sum of the distances between the lenses in the second lens group is equal to the sum of the focal lengths of the lenses in the second lens group; the lens closest to the relay lens in the second lens group is The distance between the subsequent lenses is equal to the focal length of the lens, and the sum of A and B is an even number.

In the embodiment of this application, the first lens group and the second lens group between the two-stage switching engine in the wavelength selective switch are arranged in the order of the 4f optical system, and there are a total of A+B lenses in the dispersion direction, which form (2(A+B))f optical system. After the optical signal passes through the (2(A+B))f optical system, it reaches the second switching engine. The light spot distribution area and the area where the light signal is projected on the first switching engine are Consistently, the spot distribution is within the switching area. Therefore, the cutting effect of the second switching engine on the light spot is weak, which effectively reduces the filtering cost.

In a possible implementation of the first aspect, the sum of the focal lengths of the lenses in the first lens group is equal to the focal length of the relay lens; and the sum of the focal lengths of the lenses in the second lens group is equal to the focal length of the relay lens.

In the embodiment of the present application, since the sum of the focal lengths of the lenses in the first lens group is equal to the focal length of the relay lens, and the sum of the focal lengths of the lenses in the second lens group is equal to the focal length of the relay lens, the first interactive engine outputs The beam size of is consistent with the beam size input to the second switching engine. The first exchange engine, the first lens group, the relay lens, the second lens group and the second exchange engine together form a 2f optical system centered on the relay lens.

In a possible implementation of the first aspect, the wavelength selective switch further includes: a first dispersion element and a second dispersion element;

The first dispersion element is connected to the input fiber collimation array and the first switching engine, the first dispersion element is located between the input fiber collimation array and the first switching engine; the second dispersion element is connected to the second switching engine and the output fiber collimation array Connected, the second dispersive element is located between the second switching engine and the output fiber collimating array.

In a possible implementation of the first aspect, the wavelength selection switch further includes: the third lens group includes C lenses, the fourth lens includes D lenses, C is a natural number greater than or equal to 2, and D is greater than or equal to 2. Natural number; the third lens group connects the input fiber collimation array and the first dispersive element, connects the first dispersive element and the first switching engine, the first dispersive element is located between the lenses of the third lens group; the fourth lens group is connected to the second The switching engine and the second dispersive element are connected to the second dispersive element and the output fiber collimating array, and the second dispersive element is located between the lenses of the fourth lens group. The sum of the distances between the lenses in the third lens group is equal to the sum of the focal lengths of the lenses in the third lens group; the distance between the lens closest to the first exchange engine in the third lens group and the first exchange engine is equal to that of the lens Focal length; the sum of the distances between the lenses in the fourth lens group is equal to the sum of the focal lengths of the lenses in the fourth lens group; the closest lens in the fourth lens group to the second exchange engine is equal to the distance between the second exchange engine The focal length of the lens, the sum of C and D is an even number.

In the embodiment of this application, because there are a total of (A+B) lenses in the dispersion direction between the two-stage switching engines in the wavelength selective switch, the (2(A+B))f optical system is formed, and the optical signal passes through the (2(A+B)) After the optical system reaches the second switching engine, the light spot distribution area is consistent with the area where the light signal is projected on the first switching engine, and the light spot distribution is within the switching area. Therefore, the cutting effect of the second switching engine on the light spot is weak, which effectively reduces the filtering cost. After the first dispersive element disperses the beam from the input fiber collimation array, it is projected on the first switching engine according to different wavelengths. After the beams of different wavelengths pass through the second dispersive element, the different beams in the dispersion direction are combined into one beam. . By arranging the first dispersive element and the second dispersive element, the deflection of light beams of different wavelengths is realized. By arranging the third lens group and the fourth lens group, the optical signal in the wavelength exchange switch is provided with chromatic aberration compensation, and the optical performance of the wavelength exchange switch is improved.

In a possible implementation of the first aspect, the wavelength selective switch further includes: a third dispersion element and a fourth dispersion element; the third dispersion element is located between the first switching engine and the relay lens; and the fourth dispersion element is located at the relay Between the lens and the second exchange engine.

In the embodiment of the present application, by providing the third dispersive element and the fourth dispersive element, the extra off-axis aberration generated during the transmission of the light beam is effectively reduced, and the optical performance of the wavelength selective switch is improved.

In a possible implementation of the first aspect, the wavelength selection switch further includes: a fifth lens group and a sixth lens group, the fifth lens group includes E lenses, E is a natural number greater than or equal to 2, and the fifth lens group The sum of the distances between the lenses is equal to the sum of the focal lengths of the lenses in the fifth lens group; the distance between the lens closest to the first exchange engine in the fifth lens group and the first exchange engine is equal to the focal length of the lens; the sixth lens Including F lenses, F is a natural number greater than or equal to 2, the sum of the distances between the lenses in the sixth lens group is equal to the sum of the focal lengths of the lenses in the sixth lens group; the sixth lens group is closest to the second exchange engine The distance between the lens and the second exchange engine is equal to the focal length of the lens; the fifth lens group connects the first exchange engine and the third dispersive element, connects the third dispersive element and the first lens group, and the third dispersive element is located in the fifth lens The sixth lens group connects the second lens group and the fourth dispersive element, connects the fourth dispersive element and the second exchange engine, the fourth dispersive element is located between the lenses of the sixth lens group, between E and F The sum is even.

In the embodiment of the application, the wavelength selective switch includes multiple lens groups and dispersive elements, the fifth lens group and the sixth lens group are used to compensate the dispersion and aberration of the optical signal, and the third dispersive element and the fourth dispersive element are used In order to reduce the extra off-axis aberration generated during the transmission of the beam, and to improve the optical performance of the wavelength switching switch.

In a possible implementation of the first aspect, the wavelength selection switch further includes: a seventh lens group and an eighth lens group; the seventh lens group is connected to the first exchange engine and the first lens group; the eighth lens group is connected to the second lens The seventh lens group includes G lenses, the eighth lens includes H lenses, G is a natural number greater than or equal to 2, and H is a natural number greater than or equal to 2. The sum of the distances between the lenses in the seventh lens group is equal to the sum of the focal lengths of the lenses in the seventh lens group; the distance between the lens closest to the first exchange engine in the seventh lens group and the first exchange engine is equal to that of the lens Focal length; the sum of the distances between the lenses in the eighth lens group is equal to the sum of the focal lengths of the lenses in the eighth lens group; the closest lens in the eighth lens group to the second exchange engine is equal to the distance between the second exchange engine The focal length of the lens, the sum of G and H is an even number.

In the embodiment of this application, between the two-stage switching engine in the wavelength selective switch, when the seventh lens group and the eighth lens group include lenses with curvature in the dispersion direction, they share (A+B+G+H) in the dispersion direction. ) Lenses form the (2(A+B+G+H))f optical system. After the optical signal passes through the (2(A+B+G+H))f optical system, it reaches the optical spot of the second switching engine The distribution area is consistent with the area where the light signal is projected on the first switching engine, and the light spot distribution is within the switching area. Therefore, the cutting effect of the second switching engine on the light spot is weak, which effectively reduces the filtering cost. By arranging the seventh lens group and the eighth lens group, the optical signal in the wavelength exchange switch is provided with chromatic aberration compensation, and the optical performance of the wavelength exchange switch is improved.

In a second aspect, an embodiment of the present application provides an optical splitter, which includes the wavelength selective switch of the foregoing first aspect.

In a third aspect, an embodiment of the present application provides a reconfigurable optical add/drop multiplexer, and the reconfigurable optical add/drop multiplexer includes the wavelength selective switch of the aforementioned first aspect.

It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

By arranging two or more lens groups between the switching engines, the lens group includes multiple lenses with curvature in the dispersion direction, which provides compensation for the dispersion and aberration of the optical signal, reduces the filtering cost of the wavelength selective switch, and improves The filter bandwidth of the wavelength selective switch improves the optical performance of the wavelength switch and improves the channel quality.

Description of the drawings

FIG. 1 is a schematic diagram of a reconfigurable optical add/drop multiplexer provided by an embodiment of the application;

2a is a schematic diagram of a light spot distribution on a switching engine in an embodiment of the application;

2b is a schematic diagram of another light spot distribution on the switching engine in an embodiment of the application;

Figure 2c is a schematic diagram of a filter spectrum in an embodiment of the application;

3 is a schematic diagram of a light spot of a wavelength selective switch in an embodiment of the application;

FIG. 4a is a schematic diagram of a wavelength selective switch structure according to an embodiment of the application;

FIG. 4b is a schematic diagram of a wavelength selective switch structure according to an embodiment of the application;

FIG. 5 is a schematic diagram of the optical path in the dispersion direction of the wavelength selective switch proposed in an embodiment of the application;

6 is a schematic diagram of the optical path of the wavelength selective switch switching the optical path direction proposed in an embodiment of the application;

FIG. 7 is a schematic diagram of a light spot in an embodiment of the application;

FIG. 8 is a schematic diagram of a simulation waveform of a filter bandwidth in an embodiment of the application;

FIG. 9 is a schematic diagram of another wavelength selective switch structure proposed by an embodiment of the application;

FIG. 10 is a schematic diagram of another wavelength selective switch structure proposed by an embodiment of the application;

FIG. 11 is a schematic diagram of another wavelength selective switch structure proposed by an embodiment of the application;

FIG. 12 is a schematic structural diagram of another wavelength selective switch proposed by an embodiment of the application;

FIG. 13 is a schematic diagram of another wavelength selective switch structure proposed by an embodiment of the application;

FIG. 14 is a schematic diagram of another wavelength selective switch structure proposed by an embodiment of the application.

Detailed ways

In order to enable those skilled in the art to better understand the solutions of the present application, the embodiments of the present application will be introduced below in conjunction with the drawings in the embodiments of the present application.

This application provides a wavelength selective switch (WSS) and related devices. By arranging two or more lens groups between the switching engines, the lens group includes A+B lenses with curvatures in the dispersion directions. The filtering cost of the wavelength selective switch is reduced, the filtering bandwidth of the wavelength selective switch is improved, and the channel quality is improved. The "connection" in the embodiments of this application refers to the connection on the optical path. Those skilled in the art can understand that specific optical devices may not necessarily have a substantial contact physical connection relationship, but the spatial positions of these optical devices and their own The device characteristics make them form a connection relationship on the optical path.

Please refer to FIG. 1. FIG. 1 is a schematic diagram of a reconfigurable optical add/drop multiplexer according to an embodiment of the application. The reconfigurable optical add-drop multiplexer (ROADM) in Figure 1 is a reconfigurable optical add-drop multiplexer that connects multi-dimensional light to multi-dimensional light. The reconfigurable optical add-drop multiplexer The optical branching multiplexer is based on the NxM or NxN wavelength selective switch, where N and M are positive integers greater than 1 but not the same. For the NxM wavelength selective switch or the NxN wavelength selective switch, it needs to use two or more switching engines to realize it. For ease of understanding, the wavelength selective switch of the two-stage switching engine is used as an example for description in the embodiment of this application. Yes, the wavelength selective switch proposed in the embodiment of the present application can not only be applied to the wavelength selective switch of a two-stage switching engine, but also can be applied to a wavelength selective switch of a three-stage switching engine or an interaction engine with three or more stages, which is not limited here. Next, we will introduce the filtering effect of the switching engine in the wavelength selective switch.

Please refer to Figure 2a. Figure 2a is a schematic diagram of a light spot distribution on the switching engine in an embodiment of the application. After the optical signal is received in the wavelength selection switch, the optical signal is projected on the switching engine into three light spots, namely: λ1, λ2 And λ3. The distribution of these three light spots is shown in Fig. 2a. In Fig. 2a, the abscissa is the dispersion direction, and the ordinate is the exchange optical path direction. The switching engine processes the optical signals corresponding to the three light spots. For details, please refer to FIG. 2b. FIG. 2b is a schematic diagram of another light spot distribution on the switching engine in an embodiment of the application. In Figure 2b, the horizontal line coverage area is the area where the optical signal on the switching engine undergoes wavelength switching (lambda switching). Only the optical signal projected in the horizontal line coverage area can be deflected in the wavelength direction. Take Figure 2b as an example, λ1 Only the right half of λ2, all of λ2, and the left half of λ3 can exchange wavelengths. Since λ1 and λ3 are partially cut during wavelength switching, the optical signal energy corresponding to λ1 and λ3 will be reduced after being processed by the switching engine. Specifically, FIG. 2c is an example, and FIG. 2c is a schematic diagram of a filtered spectrum in an embodiment of the application. Since λ1 and λ3 are partially cut, part of the energy will be lost after the optical signal passes through the switching engine. The effect of the partial cutting of the optical signal by the switching engine is called the filtering effect. For the filter spectrum generated by the optical signals (λ1, λ2, and λ3) in the wavelength switching area of the switching engine in Figure 2b, Figure 2c shows the wavelength on the abscissa and the transmittance on the ordinate. It can be seen that the wavelength is At the positions of λ1 and λ3, due to the decrease of transmission, the slope of the edge of the filter spectrum is small, which degrades the quality of the optical signal. At wavelengths λ1 and λ3, the slope of the edge of the filter spectrum is small, and the filtering effect is also called filtering cost.

Such a filtering effect will occur every time the first-level switching engine passes, and the embodiment of the present application provides a wavelength selective switch. After the optical signal passes through the first switching engine, the light spot projected on the edge of the wavelength switching area will not be partially cut. Therefore, the transmission efficiency of the optical signal after the first switching engine is guaranteed, the filtering cost of the wavelength selective switch is reduced, the filtering bandwidth of the wavelength selective switch is improved, and the channel quality is improved. A two-stage switching engine is taken as an example for description. For details, please refer to FIG. 3. FIG. 3 is a schematic diagram of a light spot of a wavelength selective switch in an embodiment of the application. Figure 3 shows the light spot λ1 shown in Figures 2a-2c as an example. After passing the first switching engine, only the right half has undergone wavelength switching. The wavelength-switched light spot is projected on the wavelength-exchange area (the area covered by the horizontal line) in the second switching engine. Therefore, the light spot is not partially cut. The light spot is completely projected to the wavelength-exchange area of the second switching engine. All the energy of will be exchanged, no extra energy loss will be produced, and no extra filtering cost will be produced in the second exchange engine.

Hereinafter, the wavelength selective switch proposed by the embodiment of the present application will be described with reference to the accompanying drawings. Please refer to FIG. 4a. FIG. 4a is a schematic diagram of the structure of a wavelength selective switch proposed by an embodiment of the present application. A wavelength selective switch proposed in an embodiment of the application includes: an input fiber collimator array (FCA), a first switching engine, a first lens group, a relay lens, a second lens group, and a second switching engine And output fiber collimation array.

In the embodiment of the application, the optical signal enters the wavelength selection switch through the input fiber collimation array, the input fiber collimation array performs collimation processing on the optical signal, the input collimator array is arranged in a row in the vertical direction, and the input fiber is collimated The array may also include: input ports, input optical fiber arrays, and input collimator arrays. Among them, the input port receives the input optical signal from the outside; the input side fiber array and the input collimator array; the input collimator array is arranged in a row in the vertical direction, and the optical signal from the input port is output in parallel to the subsequent optical element. Corresponding to the input fiber collimation array, the output fiber collimation array is arranged in a row in the vertical direction for outputting optical signals from the second switching engine. The output fiber collimation array includes an output collimator array and an output Optical fiber array, where the optical signal is transmitted from the output collimator array and the output optical fiber array to the output port.

After the fiber collimation array is input, the first switching engine is connected. The switching engine in the embodiment of this application includes at least two levels of switching engines: the first switching engine and the second switching engine. It should be noted that when the wavelength selection switch When the switching engine in is a three-level or above switching engine, it is similar to the case where the wavelength selective switch is a two-level switching engine, and will not be repeated here. The switching engine is used to adjust the deflection angle of the incident light and focus the corresponding light signal to the corresponding spatial position.

After the first exchange engine, the first lens group is connected, the first lens group includes A lenses, A is a natural number greater than or equal to 2, and the first lens group includes at least lenses with curvature in the dispersion direction.

After the first lens group, the relay lens is connected. The relay lens is a cylindrical lens in the direction of the exchange optical path, which can be a cylindrical lens or a combination of multiple cylindrical lenses, and only has curvature in the exchange optical path.

After the relay lens, the second lens group is connected. The second lens group includes B lenses, B is a natural number greater than or equal to 2, the first lens group is connected to the first exchange engine and the relay lens, the second lens group is connected to the relay lens and the second exchange engine, the first lens group And the second lens group includes at least a lens with curvature in the dispersion direction. The first lens group includes at least lenses with curvature in the dispersion direction, and the second lens group includes at least lenses with curvature in the dispersion direction. The lenses of the first lens group and the lenses of the second lens group can compensate for the dispersion and aberration of the optical signal. , Effectively improve the optical performance.

After the second lens group, the output fiber collimation array is connected. The output fiber collimation array includes a plurality of output ports, and the optical signal outputs a wavelength selection switch through the output port in the output fiber collimation array.

In the embodiment of the present application, two or more lens groups are arranged between the switching engines, and the lens group includes multiple lenses with curvature in the dispersion direction, which provides compensation for the dispersion and aberration of the optical signal and reduces the wavelength selection switch. The filtering cost of the wavelength selection switch increases the filtering bandwidth of the wavelength selective switch, improves the optical performance of the wavelength switch switch, and improves the channel quality.

The wavelength selective switch proposed in the embodiment of the present application may further include more optical elements. For details, please refer to FIG. 4b. FIG. 4b is a schematic diagram of the structure of a wavelength selective switch proposed in an embodiment of the present application. The wavelength selective switch proposed in the embodiment of the application includes: an input fiber collimator array (FCA), a third lens group, a first dispersion element, a first switching engine, a fifth lens group, and a third dispersion Element, fifth lens group, first lens group, relay lens, second lens group, sixth lens group, fourth dispersive element, sixth lens group, second exchange engine, fourth lens group, second dispersive element , The fourth lens group and the output fiber collimation array.

These optical components can be generally classified into the following six categories: input fiber collimation array, lens group, dispersive element, switching engine, relay lens, and output fiber collimation array. First, introduce the role of each optical element:

Specifically, the input fiber collimation array is arranged in a row in the vertical direction, and the input fiber collimation array may also include: input ports, input fiber arrays, and input collimator arrays, wherein the input ports receive external input optical signals The input side fiber array and the input collimator array; the input collimator array is arranged in a row in the vertical direction, and the optical signal from the input port is output to the subsequent optical element in parallel. The input fiber collimation array includes N input ports, and N is a natural number greater than 1. Corresponding to the input fiber collimation array, the output fiber collimation array includes M output ports, where M is a natural number greater than 1, and the output fiber collimation array is arranged in a row in the vertical direction, and is used to transfer the output from the second switching engine The optical signal output of the output fiber collimator array includes an output collimator array and an output fiber array, wherein the optical signal is transmitted from the output collimator array and the output fiber array to the output port.

The switching engine, which can be a micro-electromechanical system (MEMS) or liquid crystal on silicon (LCOS), can configure the corresponding MEMS mirror or LCOS pixel parameters according to the wavelength routing configuration information To adjust the deflection angle of the incident light, focus the corresponding light signal to the corresponding spatial position. In MEMS, the mechanical movement of the micro-mirror can be used to deflect the light beam hitting the micro-mirror, thereby realizing the deflection of the optical path, thereby realizing the dimensional (or transmission path) switching of the signal light; in LCOS, The blazed grating is formed by configuring the phase of the pixel points to deflect the corresponding incident light.

Relay lens, the relay lens is a cylindrical lens in the direction of the exchange optical path, which can be a cylindrical lens or a combination of multiple cylindrical lenses, and only has curvature in the exchange optical path. The function of the relay lens is to switch the optical signal input from the input fiber collimating array to the corresponding port of the output fiber collimating array, so that the optical signal is input to N input ports and output from M output ports. The sum of the focal lengths of the lenses in the first lens group is equal to the focal length of the relay lens; the sum of the focal lengths of the lenses in the second lens group is equal to the focal length of the relay lens.

The lens group in the embodiment of the application includes a lens. The lens can be a cylindrical lens with curvature in the dispersion direction. The cylindrical lens with curvature in the dispersion direction is used to converge or diverge the optical signal in the dispersion direction. The lens can compensate for the dispersion and dispersion of the optical signal. Aberrations can effectively improve optical performance. It can also be a lens with curvature in the direction of dispersion and curvature at the same time on the exchange optical path. At this time, the lens group can converge the optical signal in the direction of dispersion and the optical signal in the direction of the optical path. . The dispersive element includes one or more gratings, prisms and focusing lenses. The gratings can be reflective diffraction gratings or transmissive diffraction gratings, which are not limited here.

The grating or prism in the dispersive element is used to separate different wavelengths, and the focusing lens is used to collimate the light of different wavelengths from the grating and condense the single-wavelength light from the grating. The lens group and the dispersive element are used to change the beam size of the optical signal and to change the optical signal into a polarization state of polarized light.

In the embodiment of the present application, the lens group includes: a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group, and a sixth lens group, among which: the first lens group, the second lens group Each of the lens group, the third lens group, the fourth lens group, the fifth lens group, and the sixth lens group includes at least two lenses.

The first lens group includes A lenses, the second lens group includes B lenses, A is a natural number greater than or equal to 2, B is a natural number greater than or equal to 2, and the sum of A and B is an even number. The sum of the distances between the lenses in the first lens group is equal to the sum of the focal lengths of the lenses in the first lens group; the distance between the lens closest to the relay lens in the first lens group and the relay lens is equal to the focal length of the lens; The sum of the distances between the lenses in the second lens group is equal to the sum of the focal lengths of the lenses in the second lens group; the distance between the lens closest to the relay lens in the second lens group and the relay lens is equal to the focal length of the lens. The sum of the focal lengths of the lenses in the first lens group is equal to the focal length of the relay lens; the sum of the focal lengths of the lenses in the second lens group is equal to the focal length of the relay lens.

The third lens group includes C lenses, the fourth lens includes D lenses, C is a natural number greater than or equal to 2, D is a natural number greater than or equal to 2, and the sum of C and D is an even number. The sum of the distances between the lenses in the third lens group is equal to the sum of the focal lengths of the lenses in the third lens group; the distance between the lens closest to the first exchange engine in the third lens group and the first exchange engine is equal to that of the lens Focal length; the sum of the distances between the lenses in the fourth lens group is equal to the sum of the focal lengths of the lenses in the fourth lens group; the closest lens in the fourth lens group to the second exchange engine is equal to the distance between the second exchange engine The focal length of the lens.

The fifth lens group includes E lenses, E is a natural number greater than or equal to 2, the sum of the distances between the lenses in the fifth lens group is equal to the sum of the focal lengths of the lenses in the fifth lens group; the distance in the fifth lens group is the first The distance between the closest lens of the exchange engine and the first exchange engine is equal to the focal length of the lens. The sixth lens includes F lenses. F is a natural number greater than or equal to 2. The sum of the distances between the lenses in the sixth lens group is equal to The sum of the focal lengths of the lenses in the sixth lens group; the distance between the lens closest to the second exchange engine in the sixth lens group and the second exchange engine is equal to the focal length of the lens, and the sum of E and F is an even number.

The switching engine, which can be a micro-electromechanical system (MEMS) or liquid crystal on silicon (LCOS), can configure the corresponding MEMS mirror or LCOS pixel parameters according to the wavelength routing configuration information To adjust the deflection angle of the incident light, focus the corresponding light signal to the corresponding spatial position. In MEMS, the mechanical movement of the micro-mirror can be used to deflect the light beam hitting the micro-mirror, thereby realizing the deflection of the optical path, thereby realizing the dimensional (or transmission path) switching of the signal light; in LCOS, The blazed grating is formed by configuring the phase of the pixel points to deflect the corresponding incident light.

Relay lens, the relay lens is a cylindrical lens in the direction of the exchange optical path, which can be a cylindrical lens or a combination of multiple cylindrical lenses, and only has curvature in the exchange optical path. The function of the relay lens is to switch the optical signal input from the input fiber collimating array to the corresponding port of the output fiber collimating array, so that the optical signal is input to N input ports and output from M output ports. The sum of the focal lengths of the lenses in the first lens group is equal to the focal length of the relay lens; the sum of the focal lengths of the lenses in the second lens group is equal to the focal length of the relay lens.

It should be noted that those skilled in the art can understand that there are various devices that can implement the above-mentioned functions, and the embodiments of the present application are only examples.

The specific structure of the wavelength selective switch proposed in the embodiment of this application will be described below with reference to Figures 5 and 6. Figure 5 is a schematic diagram of the optical path of the wavelength selective switch proposed in the embodiment of the application in the dispersion direction, and Figure 6 is the wavelength proposed in the embodiment of the application. The schematic diagram of the optical path of the selector switch to switch the direction of the optical path.

For ease of understanding, the wavelength selection switches in Figures 5 and 6 are described using the case where the lens groups are all two lenses, the dispersive elements are all one grating, and the two-stage switching engine is used as an example. The type and number of optical components in the wavelength selective switch are limited. It can be understood that the case where the lens group in the wavelength selective switch is more than two lenses, and/or the dispersive element is one prism, and/or the switching engine with more than two stages is also covered by this application. It should be noted that "X and/or Y" in this application can be understood as: X, or Y, or X and Y.

In the wavelength selective switches shown in Figures 5 and 6, the optical signal is input from the input fiber collimation array. The input fiber collimation array includes N input fibers and N collimating lenses, which are used to combine N dimensions of input light The signal is output after collimation, and N is a natural number greater than 1.

The third lens group includes lens 1 and lens 2. Lens 1 and lens 2 can be lenses with the same or different focal lengths. Specifically, they can be cylindrical lenses with curvature in the dispersion direction. The distance between lens 1 and lens 2 is equal to lens 1. Sum of the focal length of lens 2, the distance from lens 1 to the input fiber collimation array is equal to the focal length of lens 1, and the distance from lens 2 to the first exchange engine is equal to the focal length of lens 2, that is, lens 1 and lens 2 form a wavelength direction 4f optical system. There is a first dispersive element in the third lens group. The first dispersive element includes grating 1. The light beam passes through lens 1 and enters grating 1. After the grating 1 is dispersively opened, the light beam is transmitted to the first switching engine through lens 2 at different wavelengths. In different areas, the spot distribution of the light beam projected on the first switching engine is shown in Figs. 2a-2b.

After the first switching engine, the fifth lens group is connected. The fifth lens group includes lens 3 and lens 4. Lens 3 and lens 4 can be lenses with the same or different focal lengths. The distance between lens 3 and lens 4 is equal to the sum of the focal lengths of lens 3 and lens 4. The distance of an exchange engine is equal to the focal length of lens 3, that is, lens 3 and lens 4 form a 4f optical system. There is a third dispersive element in the fifth lens group, and the grating 2 is included in the third dispersive element. The grating 2 is located between the lens 3 and the lens 4. After the optical signal passes through the first switching engine, light beams of different wavelengths pass through the grating 2, and the different light beams in the dispersion direction are combined into one light beam. By setting the third dispersive element: grating 2, it can effectively reduce the additional off-axis aberration when the light beam passes through the relay lens. When the number of input ports is large (for example: N>5), the off-axis aberration will be too large. The beam produces displacement deviation on the second switching engine, which affects the overall filtering spectrum. The position of the third dispersive element relative to the fifth lens group is determined by the optical performance parameters of the respective optical elements, and is not limited here.

After the fifth lens group, the first lens group is connected. The first lens group includes lens 5 and lens 6. Lens 5 and lens 6 can be lenses with the same or different focal lengths. The distance between lens 5 and lens 6 is equal to the sum of the focal lengths of lens 5 and lens 6, and lens 6 is centered The distance of the subsequent lens is equal to the focal length of the lens 6, that is, the lens 5 and the lens 6 form a 4f optical system, and the lenses in the first lens group can only be lenses with curvature in the dispersion direction. The optical signal passes through the lens 5 and the lens 6 to the relay lens, which is a lens that exchanges the direction of the optical path.

After the optical signal passes through the fifth lens group, it enters the relay lens, and the relay lens converts the exchange angle introduced by the first exchange engine into an offset in the beam position. The second lens group is connected after the relay lens. The second lens group includes lens 7 and lens 8. Lens 7 and lens 8 can be lenses with the same or different focal lengths. The distance between lens 7 and lens 8 is equal to lens 7 and lens 8. The sum of the focal length of the lens 8, the distance from the lens 7 to the first exchange engine is equal to the focal length of the lens 7, that is, the lens 7 and the lens 8 form a 4f optical system.

After the optical signal passes through the second lens group, it enters the sixth lens group, which is connected to the second lens group. The sixth lens group includes lens 9 and lens 10. Lens 9 and lens 10 can be lenses with the same or different focal lengths. The distance between lens 9 and lens 10 is equal to the sum of the focal lengths of lens 9 and lens 10. The distance between the two exchange engines is equal to the focal length of the lens 10, that is, the lens 9 and the lens 10 form a 4f optical system, and the lenses in the second lens group can only be lenses with curvature in the dispersion direction. There is a fourth dispersive element in the sixth lens group, and the grating 3 is included in the fourth dispersive element. The grating 3 is located between the lens 9 and the lens 10, and the optical performance of the grating 3 and the grating 2 are consistent. The grating 3 is used to turn on the beam dispersion. The position of the fourth dispersive element relative to the sixth lens group is determined by the optical performance parameters of the respective optical elements, and is not limited here.

After the optical signal passes through the second lens group, it reaches the second switching engine. According to the angle of the beam and the output port, the second-level switching engine deflects the beam again by the corresponding angle to ensure that the beam can reach the desired output port. The spot distribution of the light beam projected on the second switching engine is shown in Figs. 2a-2b.

After the light signal passes through the second switching engine, it reaches the fourth lens group. The fourth lens group includes lens 11 and lens 12. Lens 11 and lens 12 can be lenses with the same or different focal lengths. The distance between lens 11 and lens 12 Equal to the sum of the focal lengths of lens 11 and lens 12, the distance from lens 11 to the second exchange engine is equal to the focal length of lens 1, that is, lens 11 and lens 12 form a 4f optical system. There is a second dispersive element in the fourth lens group, and the grating 4 is included in the second dispersive element. The grating 3 is located between the lens 11 and the lens 12, and the optical performance of the grating 4 and the grating 1 are consistent. The grating 3 is used to combine the light beams with the dispersion turned on. The combined light beam reaches the output end. The output end contains an output fiber collimation array. The output fiber collimation array includes M input fibers and M collimating lenses, which are used to collimate the optical signal and output it to M dimensions. , M is a natural number greater than 1.

Please refer to FIG. 7 for a schematic diagram of cutting the light spot on the switching engine in the wavelength selective switch of FIGS. 5-6. FIG. 7 is a schematic diagram of a light spot in an embodiment of the application. In Figure 7, the semicircle is a kind of light spot. After passing through the first switching engine, the light spot becomes a half elliptical light spot, and the direction of the light spot faces downward. After passing through the 8f optical system composed of four lenses (lenses 3, 4, 5, and 6), the light spot propagates to the position of the relay lens. After passing through the 4f optical system composed of the first two lenses (lens 3 and lens 4), the semi-elliptical spot is flipped once, and after passing through the 4f optical system composed of the latter two lenses (lens 5 and lens 6), the spot is flipped again once. Similarly, after passing through the 8f optical system composed of four lenses (lenses 7, 8, 9, and 10), the light spot propagates to the position of the second switching engine. The direction of the light spot is consistent with the direction of the light spot emitted by the first switching engine.

In the embodiment of this application, because there are a total of 8 lenses in the dispersion direction between the two-stage switching engine in the wavelength selective switch, forming a 16f optical system, the optical signal passes through the 16f optical system and reaches the second switching engine. The area is the same as the area where the light signal is projected on the first switching engine, and the light spot distribution is within the switching area. Therefore, the cutting effect of the second switching engine on the light spot is weak, which effectively reduces the filtering cost. Please refer to FIG. 8 for details. FIG. 8 is a schematic diagram of a simulation waveform of a filtering bandwidth in an embodiment of this application. The dotted line corresponds to a two-stage cascaded 1xN wavelength selective switch, and the solid line corresponds to the wavelength selective switch proposed in this embodiment of the application. Exemplarily, in the wavelength selective switch proposed in the embodiment of the present application, the 3 decibel (dB) bandwidth of the filtered spectrum in the 50 gigahertz (GHz) channel is 44.2 GHz. The filter spectrum bandwidth of the 1xN two-stage cascaded wavelength selective switch designed with the same grating and spot size is 42.7GHz. It can be seen that the filter spectrum bandwidth of the wavelength selective switch proposed in the embodiment of this application is larger than the 1xN two-stage design of the spot size. Cascaded wavelength selective switch. It should be noted that this is only a possible simulation experiment result. According to the actual optical elements and the arrangement of the optical elements, there may be other simulation experiment results, which are not limited here. By setting the lens group between the switching engines, the filtering cost of the wavelength selective switch is reduced, the filtering bandwidth of the wavelength selective switch is increased, and the channel quality is improved.

In addition to the wavelength selective switch similar to the structure of FIG. 4a and FIG. 4b, the wavelength selective switch proposed in the embodiment of the present application may also have other structures. For details, please refer to FIG. 9, which is another example of the present application. A schematic diagram of a wavelength selective switch structure. The wavelength selective switch proposed in the embodiment of the present application includes: an input fiber collimation array, a first dispersion element, a first switching engine, a first lens group, a relay lens, and a second lens group , The second switching engine, the second dispersive element and the output fiber collimation array, where: the input fiber collimation array, the first dispersive element, the first switching engine, the first lens group, the relay lens, the second lens group, the first The second switching engine, the second dispersive element, and the output fiber collimation array are similar to the embodiment corresponding to FIG. 4b, and will not be repeated here.

In the embodiment of this application, because there are a total of A+B lenses in the dispersion direction between the two-stage switching engines in the wavelength selective switch, they form a (2(A+B))f optical system, and the optical signal passes through the (2( A+B)) After the optical system reaches the second switching engine, the light spot distribution area is consistent with the area where the light signal is projected on the first switching engine, and the light spot distribution is within the switching area. Therefore, the cutting effect of the second switching engine on the light spot is weak, which effectively reduces the filtering cost. After the first dispersive element disperses the beam from the input fiber collimation array, it is projected on the first switching engine according to different wavelengths. After the beams of different wavelengths pass through the second dispersive element, the different beams in the dispersion direction are combined into one beam. . By arranging the first dispersive element and the second dispersive element, the deflection of light beams of different wavelengths is realized.

Please refer to FIG. 10, which is a schematic structural diagram of another wavelength selective switch proposed in an embodiment of this application. The wavelength selective switch proposed in an embodiment of this application includes: an input fiber collimation array, a third lens group, and a first Dispersion element, first switching engine, first lens group, relay lens, second lens group, second switching engine, fourth lens group, second dispersing element and output fiber collimation array, among which: input fiber collimation array , The third lens group, the first dispersive element, the first exchange engine, the first lens group, the relay lens, the second lens group, the second exchange engine, the fourth lens group, the second dispersive element and the output fiber collimation array It is similar to the embodiment corresponding to FIG. 4b and will not be repeated here. The first dispersion element is located between the third lens group, the second dispersion element is located between the fourth lens group, the position of the first dispersion element relative to the third lens group, and the position of the second dispersion element relative to the fourth lens group, It is determined by the optical performance parameters of the respective optical components and is not limited here.

In the embodiment of this application, because there are a total of A+B lenses in the dispersion direction between the two-stage switching engines in the wavelength selective switch, they form a (2(A+B))f optical system, and the optical signal passes through the (2( A+B)) After the optical system reaches the second switching engine, the light spot distribution area is consistent with the area where the light signal is projected on the first switching engine, and the light spot distribution is within the switching area. Therefore, the cutting effect of the second switching engine on the light spot is weak, which effectively reduces the filtering cost. After the first dispersive element disperses the beam from the input fiber collimation array, it is projected on the first switching engine according to different wavelengths. After the beams of different wavelengths pass through the second dispersive element, the different beams in the dispersion direction are combined into one beam. . By arranging the first dispersive element and the second dispersive element, the deflection of light beams of different wavelengths is realized. By arranging the third lens group and the fourth lens group, the optical signal in the wavelength exchange switch is provided with chromatic aberration compensation, and the optical performance of the wavelength exchange switch is improved.

Please refer to FIG. 11. FIG. 11 is a schematic structural diagram of another wavelength selective switch proposed in an embodiment of this application. The wavelength selective switch proposed in an embodiment of this application includes: an input fiber collimation array, a first switching engine, and a first Lens group, third dispersive element, relay lens, second lens group, fourth dispersive element, second exchange engine and output fiber collimation array, including: input fiber collimation array, first exchange engine, first lens group The third dispersive element, the relay lens, the second lens group, the fourth dispersive element, the second switching engine, and the output fiber collimating array are similar to the embodiment corresponding to FIG. 4b, and will not be repeated here. The third dispersive element is located between the first lens group, and the fourth dispersive element is located between the second lens group, which is specifically determined by the respective optical parameters and is not limited here.

In the embodiment of this application, because there are a total of A+B lenses in the dispersion direction between the two-stage switching engines in the wavelength selective switch, they form a (2(A+B))f optical system, and the optical signal passes through the (2( A+B)) After the optical system reaches the second switching engine, the light spot distribution area is consistent with the area where the light signal is projected on the first switching engine, and the light spot distribution is within the switching area. Therefore, the cutting effect of the second switching engine on the light spot is weak, which effectively reduces the filtering cost. By arranging the third dispersive element and the fourth dispersive element, the extra off-axis aberration generated by the beam during transmission is effectively reduced, and the optical performance is improved.

Please refer to FIG. 12, which is a schematic structural diagram of another wavelength selective switch proposed in an embodiment of this application. The wavelength selective switch proposed in an embodiment of this application includes: an input fiber collimating array, a third lens group, and a first Dispersion element, first exchange engine, first lens group, third dispersion element, relay lens, second lens group, fourth dispersion element, second exchange engine, fourth lens group, second dispersion element and output fiber collimator Straight array, including: input fiber collimation array, third lens group, first dispersion element, first exchange engine, first lens group, third dispersion element, relay lens, second lens group, fourth dispersion element, The second switching engine, the fourth lens group, the second dispersive element, and the output fiber collimating array are similar to the embodiment corresponding to FIG. 4b, and will not be repeated here. The first dispersion element is located between the third lens group, the second dispersion element is located between the fourth lens group, the third dispersion element is located between the first lens group, and the fourth dispersion element is located between the second lens group. The position is determined by the respective optical performance parameters.

In the embodiment of this application, because there are a total of A+B lenses in the dispersion direction between the two-stage switching engines in the wavelength selective switch, they form a (2(A+B))f optical system, and the optical signal passes through the (2( A+B)) After the optical system reaches the second switching engine, the light spot distribution area is consistent with the area where the light signal is projected on the first switching engine, and the light spot distribution is within the switching area. Therefore, the cutting effect of the second switching engine on the light spot is weak, which effectively reduces the filtering cost. After the first dispersive element disperses the beam from the input fiber collimation array, it is projected on the first switching engine according to different wavelengths. After the beams of different wavelengths pass through the second dispersive element, the different beams in the dispersion direction are combined into one beam. . By arranging the first dispersive element and the second dispersive element, the deflection of light beams of different wavelengths is realized. By arranging the first dispersive element and the second dispersive element, the deflection of light beams of different wavelengths is realized. By arranging the third lens group and the fourth lens group, the optical signal in the wavelength exchange switch is provided with chromatic aberration compensation, and the optical performance of the wavelength exchange switch is improved. By arranging the third dispersive element and the fourth dispersive element, the extra off-axis aberration generated by the light beam during transmission is effectively reduced, and the optical performance of the wavelength switching switch is improved.

Please refer to FIG. 13, which is a schematic structural diagram of another wavelength selective switch proposed in an embodiment of this application. The wavelength selective switch proposed in an embodiment of this application includes: an input fiber collimation array, a first switching engine, and a seventh Lens group, first lens group, relay lens, second lens group, eighth lens group, second exchange engine and output fiber collimation array, including: input fiber collimation array, first exchange engine, first lens group The relay lens, the second lens group, the second switching engine, and the output fiber collimating array are similar to the embodiment corresponding to FIG. 4b, and will not be repeated here.

The seventh lens group includes U lenses, the eighth lens includes U lenses, and U is a natural number greater than or equal to 2. The lenses of the seventh lens group and the eighth lens group may be only lenses with curvature in the direction of dispersion, or only lenses with curvature in the direction of the exchange optical path, or may have curvatures in the direction of dispersion and exchange optical paths at the same time. For lenses with curvature, the sum of the distances between the lenses in the seventh lens group is equal to the sum of the focal lengths of the lenses in the seventh lens group; the lens in the seventh lens group closest to the first exchange engine is between the first exchange engine The distance of is equal to the focal length of the lens; the sum of the distances between the lenses in the eighth lens group is equal to the sum of the focal lengths of the lenses in the eighth lens group; the lens in the eighth lens group that is closest to the second exchange engine, and the second exchange engine The distance between is equal to the focal length of the lens.

In the embodiment of this application, between the two-stage switching engines in the wavelength selective switch, when the seventh lens group and the eighth lens group include lenses with curvature in the dispersion direction, they share (A+B+G+H) in the dispersion direction. Two lenses form the (2(A+B+G+H))f optical system. After the optical signal passes through the (2(A+B+G+H))f optical system, it reaches the second switching engine light spot distribution The area is the same as the area where the light signal is projected on the first switching engine, and the light spot distribution is within the switching area. Therefore, the cutting effect of the second switching engine on the light spot is weak, which effectively reduces the filtering cost. By arranging the seventh lens group and the eighth lens group, the optical signal in the wavelength exchange switch is provided with chromatic aberration compensation, and the optical performance of the wavelength exchange switch is improved.

Please refer to FIG. 14. FIG. 14 is a schematic structural diagram of another wavelength selective switch proposed in an embodiment of this application. The wavelength selective switch proposed in an embodiment of this application includes: an input fiber collimation array, a third lens group, and a first Dispersion element, first exchange engine, seventh lens group, first lens group, relay lens, second lens group, eighth lens group, second exchange engine, fourth lens group, second dispersion element and output fiber collimator Straight array, including: input fiber collimation array, third lens group, first dispersive element, first exchange engine, first lens group, relay lens, second lens group, second exchange engine, fourth lens group, The second dispersive element and the output fiber collimation array are similar to the embodiment corresponding to FIG. 4b, and will not be repeated here. The seventh lens group and the eighth lens group are similar to the embodiment corresponding to FIG. 13 and will not be repeated here. The first dispersion element is located between the third lens group, the second dispersion element is located between the fourth lens group, the third dispersion element is located between the first lens group, and the fourth dispersion element is located between the second lens group. The position is determined by the respective optical performance parameters.

In the embodiment of this application, between the two-stage switching engines in the wavelength selective switch, when the seventh lens group and the eighth lens group include lenses with curvature in the dispersion direction, they share (A+B+G+H) in the dispersion direction. Two lenses form the (2(A+B+G+H))f optical system. After the optical signal passes through the (2(A+B+G+H))f optical system, it reaches the second switching engine light spot distribution The area is the same as the area where the light signal is projected on the first switching engine, and the light spot distribution is within the switching area. Therefore, the cutting effect of the second switching engine on the light spot is weak, which effectively reduces the filtering cost. After the first dispersive element disperses the beam from the input fiber collimation array, it is projected on the first switching engine according to different wavelengths. After the beams of different wavelengths pass through the second dispersive element, the different beams in the dispersion direction are combined into one beam. . By arranging the first dispersive element and the second dispersive element, the deflection of light beams of different wavelengths is realized. By providing the third lens group, the fourth lens group, the seventh lens group and the eighth lens group, the optical signal in the wavelength exchange switch is provided with chromatic aberration compensation and the optical performance of the wavelength exchange switch is improved.

The terms "first", "second", etc. in the description and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific sequence or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments described herein can be implemented in an order other than the content illustrated or described herein. In addition, the terms "including" and "having" and any variations of them are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or modules is not necessarily limited to the clearly listed Those steps or modules may include other steps or modules that are not clearly listed or are inherent to these processes, methods, products, or equipment. The naming or numbering of steps appearing in this application does not mean that the steps in the method flow must be executed in the time/logical order indicated by the naming or numbering. The named or numbered process steps can be implemented according to the The technical purpose changes the execution order, as long as the same or similar technical effects can be achieved.

Those skilled in the art can clearly understand that, for the convenience and conciseness of description, the specific working process of the above-described system, device, and unit can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, device, and method may be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components can be combined or It can be integrated into another system, or some features can be ignored or not implemented.

As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present application, not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, a person of ordinary skill in the art should understand that: The technical solutions recorded in the embodiments are modified, or some of the technical features are equivalently replaced; these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims (14)

A wavelength selective switch, characterized in that the wavelength selective switch comprises: an input fiber collimation array, a first switching engine, a relay lens, a first lens group, a second lens group, a second switching engine, and an output fiber collimator Straight array The input fiber collimation array includes a plurality of input ports; The first switching engine is connected to the input fiber collimation array; The relay lens is connected to the first switching engine and the second switching engine, the relay lens is located between the first switching engine and the second switching engine, and the relay lens is a switching engine. Lens in the direction of the optical path; The first lens group includes A lenses, the second lens group includes B lenses, where A is a natural number greater than or equal to 2, and the B is a natural number greater than or equal to 2, and the first lens group Connecting the first switching engine and the relay lens, the second lens group connecting the relay lens and the second switching engine, and the first lens group includes at least a lens with curvature in the dispersion direction, The second lens group includes at least a lens with curvature in a dispersion direction; The output fiber collimation array includes a plurality of output ports, and the output fiber collimation array is connected to the second switching engine. The wavelength selective switch according to claim 1, wherein: The sum of the distances between the lenses in the first lens group is equal to the sum of the focal lengths of the lenses in the first lens group; The distance between the lens closest to the relay lens in the first lens group and the relay lens is equal to the focal length of the lens; The sum of the distances between the lenses in the second lens group is equal to the sum of the focal lengths of the lenses in the second lens group; The distance between the lens closest to the relay lens in the second lens group and the relay lens is equal to the focal length of the lens; The sum of A and B is an even number. The wavelength selective switch according to claim 2, wherein: The sum of the focal lengths of the lenses in the first lens group is equal to the focal length of the relay lens; The sum of the focal lengths of the lenses in the second lens group is equal to the focal length of the relay lens. The wavelength selective switch according to claim 3, wherein the wavelength selective switch further comprises: a first dispersion element and a second dispersion element; The first dispersion element is connected to the input fiber collimation array and the first switching engine, and the first dispersion element is located between the input fiber collimation array and the first switching engine; The second dispersion element is connected to the second switching engine and the output fiber collimation array, and the second dispersion element is located between the second switching engine and the output fiber collimation array. The wavelength selective switch according to claim 4, wherein the wavelength selective switch further comprises: a third lens group and a fourth lens group; The third lens group includes C lenses, the fourth lens includes D lenses, the C is a natural number greater than or equal to 2, and the D is a natural number greater than or equal to 2; The third lens group connects the input fiber collimation array and the first exchange engine, and the first dispersive element is located between the lenses of the third lens group; The fourth lens group connects the second switching engine and the second dispersive element, connects the second dispersive element and the output fiber collimating array, and the second dispersive element is located in the fourth lens group Between the lenses. The wavelength selective switch according to claim 5, wherein: The sum of the distances between the lenses in the third lens group is equal to the sum of the focal lengths of the lenses in the third lens group; The distance between the lens closest to the first exchange engine in the third lens group and the first exchange engine is equal to the focal length of the lens; The sum of the distances between the lenses in the fourth lens group is equal to the sum of the focal lengths of the lenses in the fourth lens group; The distance between the lens closest to the second exchange engine in the fourth lens group and the second exchange engine is equal to the focal length of the lens; The sum of C and D is an even number. The wavelength selective switch according to any one of claims 3 or 6, wherein the wavelength selective switch further comprises: a third dispersion element and a fourth dispersion element; The third dispersive element is located between the first switching engine and the relay lens; The fourth dispersive element is located between the relay lens and the second exchange engine. 8. The wavelength selective switch according to claim 7, wherein the wavelength selective switch further comprises: a fifth lens group and a sixth lens group; The fifth lens group includes E lenses, the sixth lens includes F lenses, the E is a natural number greater than or equal to 2, and the F is a natural number greater than or equal to 2; The fifth lens group is connected to the first exchange engine and the first lens group, and the third dispersive element is located between the lenses of the fifth lens group; The sixth lens group is connected to the second lens group and the second exchange engine, and the fourth dispersive element is located between the lenses of the sixth lens group. The wavelength selective switch according to claim 8, wherein: The sum of the distances between the lenses in the fifth lens group is equal to the sum of the focal lengths of the lenses in the fifth lens group; The distance between the lens closest to the first exchange engine in the fifth lens group and the first exchange engine is equal to the focal length of the lens; The sum of the distances between the lenses in the sixth lens group is equal to the sum of the focal lengths of the lenses in the sixth lens group; The distance between the lens closest to the second exchange engine in the sixth lens group and the second exchange engine is equal to the focal length of the lens; The sum of the E and the F is an even number. 8. The wavelength selective switch according to claim 7, wherein the wavelength selective switch specifically comprises: The third dispersive element is connected to the first lens group, and the third dispersive element is located between the first lens group; The fourth dispersive element is connected to the second lens group, and the fourth dispersive element is located between the second lens group. The wavelength selective switch according to any one of claims 3 or 6, wherein the wavelength selective switch further comprises: a seventh lens group and an eighth lens group; The seventh lens group is connected to the first exchange engine and the first lens group; The eighth lens group is connected to the second lens group and the second exchange engine; The seventh lens group includes G lenses, the eighth lens includes H lenses, the U is a natural number greater than or equal to 2, and the G is a natural number greater than or equal to 2. The wavelength selective switch according to claim 11, wherein: The sum of the distances between the lenses in the seventh lens group is equal to the sum of the focal lengths of the lenses in the seventh lens group; The distance between the lens closest to the first exchange engine in the seventh lens group and the first exchange engine is equal to the focal length of the lens; The sum of the distances between the lenses in the eighth lens group is equal to the sum of the focal lengths of the lenses in the eighth lens group; The distance between the lens closest to the second exchange engine in the eighth lens group and the second exchange engine is equal to the focal length of the lens; The sum of the G and the H is an even number. An optical splitter, characterized in that the optical splitter comprises: the wavelength selective switch according to any one of claims 1-12. A reconfigurable optical add/drop multiplexer, characterized in that the reconfigurable optical add/drop multiplexer comprises: the wavelength selective switch according to any one of claims 1-12.

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