CN116413861A

CN116413861A - Wavelength selective switch

Info

Publication number: CN116413861A
Application number: CN202111640047.0A
Authority: CN
Inventors: 贾伟; 邓宁; 吴云飞
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-12-29
Filing date: 2021-12-29
Publication date: 2023-07-11
Also published as: WO2023125516A1

Abstract

The application discloses a wavelength selective switch for improving signal transmission's stability. The signal light input ports and the dummy light input ports are distributed along a first direction. The first dispersion element is used for decomposing the signal light from the signal light input port into a plurality of sub-wavelength signal lights in the second direction and decomposing the spurious light from the spurious light input port into a plurality of sub-wavelength spurious lights in the second direction. Wherein the second direction is perpendicular to the first direction. The first optical switch array is used for adjusting the deflection directions of the plurality of sub-wavelength signal lights. The sub-wavelength signal light and the sub-wavelength spurious light of the same wavelength are incident on the second optical switch array at the same position. The second optical switch array is used for adjusting the deflection direction of the incident light at each incident position so that the sub-wavelength signal light or sub-wavelength pseudo light of each wavelength is transmitted to the output port. The second optical switch array is used for selecting one of sub-wavelength signal light and sub-wavelength false light of each wavelength, and the selected light is transmitted to the output port.

Description

Wavelength selective switch

Technical Field

The present application relates to the field of optical communications, and in particular, to a wavelength selective switch.

Background

With the rapid increase of data traffic in networks, the demand for network transmission capacity is also increasing. The network transmission capacity can be increased, for example, by increasing the channel operating spectral width (the number of channels), for example, by expanding the original C-band to the C-band and L-band.

However, as the channel spectrum width increases, in a multi-wavelength transmission system link, there is an effect of stimulated raman scattering (Stimulated Raman Scattering, SRS), and transmission power of a short band is shifted to transmission power of a long band. In the steady state where no up-or down-wave occurs, power transfer between the multi-wavelength signals due to SRS effect is stable. When the up-wave or down-wave occurs, the number, distribution, position and the like of the multi-wavelength signals are randomly changed, so that the SRS effect is complex to change, the bearing capacity of the system is possibly exceeded, and the stability of signal transmission is reduced.

Disclosure of Invention

The embodiment of the application provides a wavelength selective switch (Wavelength Selective Switch, WSS) for improving stability of signal transmission.

In a first aspect, the present application provides a wavelength selective switch. The wavelength selective switch includes: the optical fiber comprises a signal light input port, a false light input port, an output port, a first dispersion element, a second dispersion element, a first optical switch array, a second optical switch array, a first lens group, a second lens group and a third lens group. Wherein the signal light input ports and the dummy light input ports are distributed along the first direction.

The first dispersion element is used for decomposing the signal light from the signal light input port into a plurality of sub-wavelength signal lights in the second direction and decomposing the spurious light from the spurious light input port into a plurality of sub-wavelength spurious lights in the second direction. Wherein the second direction is perpendicular to the first direction. The first lens group is used for collimating the plurality of sub-wavelength signal lights and the plurality of sub-wavelength false lights in a second direction. The first optical switch array is used for adjusting the deflection directions of a plurality of sub-wavelength signal lights from the first lens. The second lens group is used for guiding the sub-wavelength signal light from the first optical switch array and the sub-wavelength false light from the first lens group to the second optical switch array. Wherein the incidence positions of the sub-wavelength signal light and the sub-wavelength spurious light of the same wavelength on the second optical switch array are the same. The second optical switch array is used for adjusting the deflection direction of the incident light at each incident position so that the sub-wavelength signal light or sub-wavelength pseudo light of each wavelength is transmitted to the output port. The third lens group is used for converging the sub-wavelength signal light and/or sub-wavelength false light from the second optical switch array in the second direction. The second dispersive element is used for combining sub-wavelength signal light and/or sub-wavelength false light from the third lens group and guiding the combined light to the output port.

In this embodiment, even if a signal light with a certain wavelength drops during the transmission process, the second optical switch array may select the spurious light with the certain wavelength to upload the spurious light, so as to fill the channel of the dropped signal light, thereby maintaining a full wave state, stabilizing the SRS effect, and improving the stability of signal transmission. In addition, the second optical switch array is adopted only by switching in two output directions, so that the adjusting speed is higher, and the signal light and the false light can be rapidly uploaded.

In some possible embodiments, if the energy attenuation of the signal light of the first sub-wavelength incident at the first incident position on the second optical switch array is greater than or equal to a preset value, the spurious light of the first sub-wavelength incident at the first incident position is transmitted to the output port through the second optical switch array. If the energy attenuation of the first sub-wavelength signal light incident at the first incident position on the second optical switch array is smaller than a preset value, the first sub-wavelength signal light is transmitted to the output port through the second optical switch array.

In this embodiment, the sub-wavelength signal light and the sub-wavelength spurious light with the same wavelength can be reasonably selected by detecting the energy of the sub-wavelength signal light incident on the second optical switch array, so that the normally transmitted sub-wavelength signal light can still continue to be transmitted, and the abnormally transmitted sub-wavelength signal light can be ensured to be in a full-wave state after passing through the WSS by uploading the sub-wavelength spurious light.

In some possible implementations, the plurality of sub-wavelength spurious lights from the first set of mirrors are transmitted through the first optical switch array to the second set of mirrors. That is, the first optical switch array can also adjust the deflection direction of the incident sub-wavelength spurious light, which expands the application scenario of the scheme.

In some possible embodiments, the first optical switch array is further configured to adjust a deflection direction of the second sub-wavelength spurious light from the first lens group. Wherein the second sub-wavelength spurious light whose deflection direction is adjusted is not directed to the second optical switch array. The second optical switch array is used for adjusting the deflection direction of the second sub-wavelength signal light from the second lens group so as to attenuate the energy transmitted by the second sub-wavelength signal light to the output port. Wherein the second sub-wavelength spurious light is the same wavelength as the second sub-wavelength signal light. In this embodiment, before the second sub-wavelength signal light is attenuated by the second optical switch array, the first optical switch array is required to block the second sub-wavelength spurious light, so as to avoid the second sub-wavelength spurious light being enhanced while the second sub-wavelength signal light is attenuated, and ensure the attenuation effect.

In some possible embodiments, the third sub-wavelength signal light is not directed to the second optical switch array after the first optical switch array adjusts the deflection direction. The second optical switch array is used for adjusting the deflection direction of the third sub-wavelength false light from the second lens group so as to attenuate the energy transmitted by the third sub-wavelength false light to the output port. Wherein the third sub-wavelength spurious light is the same wavelength as the third sub-wavelength signal light. In this embodiment, before the third sub-wavelength spurious light is attenuated by the second optical switch array, the first optical switch array is required to block the third sub-wavelength signal light, so as to avoid the third sub-wavelength spurious light from being attenuated and enhance the third sub-wavelength signal light, thereby ensuring the attenuation effect.

In some possible implementations, the WSS further includes a fourth lens group and a fifth lens group. The fourth lens group is used for collimating and beam shaping the signal light from the signal light input port and guiding the signal light to the first dispersing element, and collimating and beam shaping the false light from the false light input port and guiding the false light to the first dispersing element. The fifth mirror group is used to first collimate and beam shape the combined light from the second dispersive element and redirect the collimated light to the output port. By the mode, the light can be collimated and shaped before dispersion and after wave combination, and the practicability of the scheme is enhanced.

In some possible embodiments, the first lens group includes a first lens, a second lens, and a third lens. The first lens is used for transmitting the plurality of sub-wavelength signal lights from the first dispersing element or refracting the plurality of sub-wavelength signal lights from the first dispersing element in a first direction. The second lens is used for transmitting the plurality of sub-wavelength false lights from the first dispersing element or refracting the plurality of sub-wavelength false lights from the first dispersing element in a first direction. The third lens is used for collimating the plurality of sub-wavelength signal lights from the first lens in the second direction and collimating the plurality of sub-wavelength false lights from the second lens. By the mode, the specific implementation mode of the first lens group is provided, and the feasibility of the scheme is improved. In a scene having a plurality of signal light input ports, the multiplexed signal light may be focused to the same position of the first optical switch array in the first direction by the first lens, and the dummy light may be directed to other positions of the first optical switch array in the first direction by the second lens.

In some possible embodiments, the second lens group includes a fourth lens, a fifth lens, and a sixth lens. The fourth lens is used for converging the sub-wavelength signal light from the first optical switch array in the second direction and converging the sub-wavelength false light from the first lens group. The fifth lens is used for converging the sub-wavelength signal light and the sub-wavelength spurious light from the fourth lens in the first direction. The sixth lens is used for collimating the sub-wavelength signal light and the sub-wavelength spurious light from the fifth lens in the second direction and guiding the sub-wavelength signal light and the sub-wavelength spurious light to the second optical switch array. By the mode, a specific implementation mode of the second lens group is provided, and the feasibility of the scheme is improved.

In some possible embodiments, the third lens group includes a seventh lens and an eighth lens. The seventh lens is used for converging the sub-wavelength signal light from the second optical switch array in the second direction and converging the sub-wavelength spurious light from the second optical switch array. The eighth lens is used for carrying out beam shaping on the sub-wavelength signal light and the sub-wavelength false light from the seventh lens. Through the mode, a specific implementation mode of the third lens group is provided, and the feasibility of the scheme is improved.

In some possible implementations, the first optical switch array is a liquid crystal on silicon (Liquid Crystal on Silicon, LCOS) and the second optical switch array is a digital light processor (Digital Light Processer, DLP). It should be appreciated that LCOS can support adjustment of any deflection direction, and the application scenario is wider. DLPs typically support only two deflection directions, and polarization direction switching can be achieved more quickly.

In some possible embodiments, the WSS further includes a controller, where the first optical switch array and the second optical switch array are controlled by the controller, so as to control the first optical switch array to perform wavelength selection according to practical situations, and control the second optical switch array to perform one of sub-wavelength signal light and sub-wavelength spurious light with the same wavelength according to practical situations.

In a second aspect, the present application provides a wavelength selective switch. The wavelength selective switch includes: the optical fiber comprises a signal light input port, a false light input port, an output port, a first dispersion element, a second dispersion element, an optical switch array, a first polarization conversion device, a second polarization conversion device, a polarization beam combiner, a polarization conversion array, a polarization separator, a first lens group, a second lens group and a third lens group. Wherein the signal light input ports and the dummy light input ports are distributed along the first direction.

The first polarization conversion device is used for converting the signal light from the signal light input port into a first polarization state. The second polarization conversion device is used for converting the false light from the false light input port into a second polarization state. Wherein the first polarization state and the second polarization state are orthogonal to each other. The first dispersion element is used for decomposing the signal light from the first polarization conversion device into a plurality of sub-wavelength signal lights in the second direction and decomposing the spurious light from the second polarization conversion device into a plurality of sub-wavelength spurious lights in the second direction. Wherein the second direction is perpendicular to the first direction. The first lens group is used for collimating the plurality of sub-wavelength signal lights and the plurality of sub-wavelength false lights in a second direction. The optical switch array is used for adjusting the deflection directions of the plurality of sub-wavelength signal lights from the first lens. The second lens group is used for guiding the sub-wavelength signal light from the optical switch array and the sub-wavelength false light from the first lens group to the polarization beam combiner. The polarization beam combiner is used for combining the sub-wavelength signal light from the second lens group and the sub-wavelength false light and guiding the combined sub-wavelength signal light and sub-wavelength false light to the polarization conversion array. Wherein the incidence positions of the sub-wavelength signal light and the sub-wavelength false light with the same wavelength on the polarization conversion array are the same. The polarization conversion array is used for adjusting the polarization state of incident light at each incident position to select the polarization state of each sub-wavelength signal light output from the polarization conversion array and the polarization state of each sub-wavelength pseudo light. Wherein the sub-wavelength signal light of the same wavelength output from the polarization conversion array and the sub-wavelength pseudo light have different polarization states. The polarization separator is used for transmitting sub-wavelength signal light and/or sub-wavelength false light with a first polarization state from the polarization conversion array and reflecting sub-wavelength signal light and/or sub-wavelength false light with a second polarization state from the polarization conversion array. The third lens group is used for converging the sub-wavelength signal light and/or sub-wavelength false light transmitted by the polarization separator in the second direction. The second dispersive element is used for combining sub-wavelength signal light and/or sub-wavelength false light from the third lens group and guiding the combined light to the output port.

In this embodiment, even if a signal light with a certain wavelength drops during transmission, the spurious light with the certain wavelength can be selected by the polarization conversion array and the deflection separator to upload the spurious light, so as to fill the channel of the dropped signal light, thereby maintaining a full wave state, stabilizing SRS effect, and improving stability of signal transmission. In addition, the polarization conversion array is adopted, only the incident light needs to be converted between two polarization states, the adjusting speed is higher, and the signal light and the false light can be rapidly uploaded.

In some possible embodiments, if the energy attenuation of the first sub-wavelength signal light incident at the first incident position on the polarization conversion array is greater than or equal to a preset value, the first sub-wavelength spurious light incident at the first incident position has a first polarization state after passing through the polarization conversion array, and the first sub-wavelength signal light has a second polarization state after passing through the polarization conversion array. If the energy attenuation of the first sub-wavelength signal light incident at the first incident position on the second optical switch array is smaller than a preset value, the first sub-wavelength false light has a second polarization state after passing through the polarization conversion array, and the first sub-wavelength signal light has a first polarization state after passing through the polarization conversion array.

In this embodiment, the sub-wavelength signal light and the sub-wavelength spurious light with the same wavelength can be reasonably selected by detecting the energy of the sub-wavelength signal light incident on the polarization conversion array, so that the normally transmitted sub-wavelength signal light can still be continuously transmitted, and the abnormally transmitted sub-wavelength signal light can be in a full-wave state by uploading the sub-wavelength spurious light so as to ensure that the light passing through the WSS is in a full-wave state.

In some possible implementations, the plurality of sub-wavelength spurious lights from the first set of mirrors are transmitted through the optical switch array to the second set of mirrors. That is, the optical switch array can also adjust the deflection direction of the incident sub-wavelength false light, and expands the application scene of the scheme.

In some possible embodiments, the optical switch array is further configured to adjust a direction of deflection of the second sub-wavelength spurious light from the first mirror group, wherein the second sub-wavelength spurious light with the adjusted direction of deflection is not directed to the polarization beam combiner. The polarization conversion array is used for adjusting the polarization state of the second sub-wavelength signal light from the polarization beam combiner to attenuate the energy transmitted by the second sub-wavelength signal light to the output port. Wherein the second sub-wavelength spurious light is the same wavelength as the second sub-wavelength signal light. In this embodiment, before the second sub-wavelength signal light is attenuated by the polarization conversion array, the second sub-wavelength spurious light needs to be blocked by the optical switch array, so that the second sub-wavelength spurious light is prevented from being enhanced while the second sub-wavelength signal light is attenuated, and the attenuation effect is ensured.

In some possible embodiments, the third sub-wavelength signal light is not directed to the polarization beam combiner after the deflection direction is adjusted by the optical switch array. The polarization conversion array is used for adjusting the polarization state of the third sub-wavelength pseudo light from the polarization beam combiner to attenuate the energy transmitted by the third sub-wavelength pseudo light to the output port. Wherein the third sub-wavelength spurious light is the same wavelength as the third sub-wavelength signal light. In this embodiment, before the third sub-wavelength spurious light is attenuated by the polarization conversion array, the optical switch array is required to block the third sub-wavelength signal light, so as to avoid the third sub-wavelength spurious light from being attenuated and enhance the third sub-wavelength signal light, thereby ensuring the attenuation effect.

In some possible implementations, the WSS further includes a fourth lens group and a fifth lens group. The fourth lens group is used for collimating and beam shaping the signal light from the signal light input port and guiding the signal light to the first polarization conversion device, and collimating and beam shaping the false light from the false light input port and guiding the false light to the first polarization conversion device. The fifth mirror group is used to first collimate and beam shape the combined light from the second dispersive element and redirect the collimated light to the output port. By the mode, the light can be collimated and shaped before dispersion and after wave combination, and the practicability of the scheme is enhanced.

In some possible embodiments, the first lens group includes a first lens, a second lens, and a third lens. The first lens is used for transmitting the plurality of sub-wavelength signal lights from the first dispersing element or refracting the plurality of sub-wavelength signal lights from the first dispersing element in a first direction. The second lens is used for transmitting the plurality of sub-wavelength false lights from the first dispersing element or refracting the plurality of sub-wavelength false lights from the first dispersing element in a first direction. The third lens is used for collimating the plurality of sub-wavelength signal lights from the first lens in the second direction and collimating the plurality of sub-wavelength false lights from the second lens. By the mode, the specific implementation mode of the first lens group is provided, and the feasibility of the scheme is improved. In a scene with multiple signal light input ports, multiple signal lights can be focused to the same position of the optical switch array in the first direction through a first lens, and false lights can be guided to other positions of the optical switch array in the first direction through a second lens.

In some possible embodiments, the second lens group includes a fourth lens, a fifth lens, a sixth lens, a seventh lens, and a mirror. The fourth lens is used for converging the sub-wavelength signal light from the optical switch array in the second direction and converging the sub-wavelength false light from the first lens group. The fifth lens is used for carrying out beam shaping on the sub-wavelength signal light from the fourth lens. The sixth lens is used for collimating the sub-wavelength signal light from the fifth lens in the second direction and guiding the sub-wavelength signal light to the polarization beam combiner. The seventh lens is used for beam shaping the sub-wavelength spurious light from the fourth lens. The mirror is used for reflecting the sub-wavelength spurious light from the seventh lens to the polarization beam combiner. By the mode, a specific implementation mode of the second lens group is provided, and the feasibility of the scheme is improved.

In some possible embodiments, the third lens group includes an eighth lens and a ninth lens. The eighth lens is used for converging the sub-wavelength signal light from the polarization separator in the second direction and converging the sub-wavelength false light from the polarization separator. The ninth lens is for beam shaping the sub-wavelength signal light and the sub-wavelength spurious light from the eighth lens. Through the mode, a specific implementation mode of the third lens group is provided, and the feasibility of the scheme is improved.

In some possible implementations, the optical switch array is an LCOS and the polarization conversion array is a ferroelectric liquid crystal on silicon (Ferroelectric Liquid Crystal on Silicon, F-LCOS). It should be appreciated that LCOS can support adjustment of any deflection direction, and the application scenario is wider. F-LCOS generally only supports two polarization states, and polarization state switching can be achieved more quickly.

In some possible embodiments, the WSS further includes a controller, and the optical switch array and the polarization conversion array are controlled by the controller, so that the optical switch array is controlled to perform wavelength selection according to practical situations, and the polarization conversion array is controlled to adjust the polarization state of incident light according to practical situations, and the polarization separator is combined to perform one-to-one selection on sub-wavelength signal light and sub-wavelength false light with the same wavelength.

In the embodiment of the application, the WSS is provided with a signal light input port and a fake light input port, wherein the fake light is a light beam which does not bear information. The signal light and the spurious light are dispersed after passing through the dispersion element, and are decomposed into a plurality of sub-wavelength signal lights and a plurality of sub-wavelength spurious lights. The first optical switch array is used for adjusting the deflection directions of a plurality of sub-wavelength signal lights so as to select the sub-wavelength signal lights transmitted to the second optical switch array. The incidence positions of the sub-wavelength signal light and the sub-wavelength false light with the same wavelength on the second optical switch array are the same, and the second optical switch array is used for adjusting the deflection direction of the incident light at each incidence position, so that the sub-wavelength signal light and the sub-wavelength false light with each wavelength are selected, and the selected sub-wavelength signal light or the sub-wavelength false light can be transmitted to the output port. In this way, even if the signal light with a certain wavelength drops in the transmission process, the second optical switch array can select the spurious light with the wavelength to realize the uploading of the spurious light so as to fill the channel of the dropped signal light, thereby maintaining the full wave state, stabilizing the SRS effect and improving the stability of signal transmission. In addition, the second optical switch array is adopted only by switching in two output directions, so that the adjusting speed is higher, and the signal light and the false light can be rapidly uploaded.

Drawings

Fig. 1 is a schematic diagram of an optical transmission system according to an embodiment of the present application;

fig. 2 (a) is a schematic diagram of a first optical path of a WSS in a dispersion direction according to an embodiment of the present application;

fig. 2 (b) is a schematic diagram of a first optical path of the WSS in the port direction in the embodiment of the present application;

FIG. 3 (a) is a schematic diagram showing the distribution of the sub-wavelength signal light and sub-wavelength spurious light spots on the first optical switch array;

FIG. 3 (b) is a schematic diagram of the spot distribution of sub-wavelength signal light and sub-wavelength spurious light on the second optical switch array;

fig. 4 (a) is a schematic diagram of a second optical path of the WSS in the dispersion direction in the embodiment of the present application;

fig. 4 (b) is a schematic diagram of a second optical path of the WSS in the port direction in the embodiment of the present application;

fig. 5 (a) is a schematic diagram of a third optical path of the WSS in the dispersion direction in the embodiment of the present application;

fig. 5 (b) is a schematic diagram of a third optical path of the WSS in the port direction in the embodiment of the present application;

fig. 6 (a) is a schematic diagram of a fourth optical path of the WSS in the dispersion direction in the embodiment of the present application;

fig. 6 (b) is a schematic diagram of a fourth optical path of the WSS in the port direction in the embodiment of the present application.

Detailed Description

The embodiment of the application provides a wavelength selective switch (Wavelength Selective Switch, WSS), which can maintain a full wave state by rapidly uploading false light to fill a channel of a signal light of a wave-down, has stable SRS effect and improves the stability of signal transmission. The terms first, second and the like in the description and in the claims of the present application and in the above-described figures, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and are merely illustrative of the manner in which the embodiments of the application described herein have been described for objects of the same nature. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Fig. 1 is a schematic diagram of an optical transmission system according to an embodiment of the present application. As shown in fig. 1, the optical transmission system includes an optical amplifier 1, an optical amplifier 2, a wavelength selective switch 1, a wavelength selective switch 2, an Add Drop WSS (ADWSS) 1, and an Add/Drop wavelength selective switch 2. It should be appreciated that the channel should be in a full wave state in order to ensure that the SRS effect is stable. The light transmitted on the channel may include signal light and spurious light, where spurious light is light that does not carry a signal. That is, part of the idle channels that do not transmit signal light may be filled with dummy light. As an example, the light passing through the optical amplifier 1 is in a full wave state in which the wavelengths of the signal light are λ1 to λ4 and the wavelengths of the pseudo light are λ5 and λ6. After the full wave light passes through the wavelength selective switch 1, the signal light having the wavelength λ1 is downloaded to the upper and lower wavelength selective switches 1. Then, the spurious light of the wavelength λ5 and the wavelength λ6 is blocked by the wavelength selective switch 1, and the upper and lower wavelength selective switches 2 upload the signal light of the wavelength λ5 and the wavelength λ6 to the wavelength selective switch 2. Further, the wavelength selective switch 2 also subjects the upper carrier wave to a spurious light of a length λ1 so that the light output from the wavelength selective switch 2 to the optical amplifier 2 is still in a full wave state.

Through the above description, when light with certain wavelengths suddenly and passively drops due to the influence of the damage of a laser light source or the failure of an optical amplifier, the WSS needs to be able to quickly upload false light to fill channels of the dropped signals, so as to reduce signal power fluctuation and damage caused by transient effects or SRS effects of the optical amplifier to the greatest extent. The WSS provided in the embodiments of the present application will be described in detail below.

For convenience of description, in the following embodiments, the transmission direction of light is generally defined as the Z direction, the distribution direction of ports is defined as the X direction, and the dispersion direction of light is defined as the Y direction. Wherein, the X direction is perpendicular to the Z direction, the Y direction is perpendicular to the Z direction, and the X direction is perpendicular to the Y direction. In addition, the present application does not limit the number of signal light input ports, dummy light input ports, and output ports, and the number shown in the drawings is only one example.

Fig. 2 (a) is a schematic diagram of a first optical path of the WSS in a dispersion direction in an embodiment of the present application. Fig. 2 (b) is a schematic diagram of a first optical path of the WSS in the port direction in the embodiment of the present application. As shown in fig. 2 (a) and 2 (b), the wavelength selective switch includes: a signal light input port 10, a false light input port 20, a first dispersive element 30, a first optical switch array 40, a second optical switch array 50, a second dispersive element 60, an output port 70, a mirror group 1, a mirror group 2, and a mirror group 3. Wherein the signal light input ports 10 and the dummy light input ports 20 are distributed in the X direction. Optionally, the wavelength selective switch may further comprise a lens group 4 and a lens group 5.

Specifically, the lens group 4 is used to first collimate and beam-shape the signal light from the signal light input port 10 and then redirect the signal light to the first dispersive element 30, and to first collimate and beam-shape the spurious light from the spurious light input port 20 and then redirect the spurious light to the first dispersive element 30. The first dispersion element 30 is for decomposing the signal light from the signal input port 10 into a plurality of sub-wavelength signal lights in the Y direction, and decomposing the pseudolight from the pseudolight input port 20 into a plurality of sub-wavelength pseudolights in the Y direction. Wherein the wavelengths of the plurality of sub-wavelength signal lights are different from each other, and the wavelengths of the plurality of sub-wavelength spurious lights are different from each other. The lens group 1 is configured to collimate a plurality of sub-wavelength signal lights and a plurality of sub-wavelength spurious lights in the Y direction, so as to convert an angular difference in the wavelength direction into a position difference in the wavelength direction, wherein the plurality of sub-wavelength signal lights are respectively incident on different positions of the first optical switch array 40, and the plurality of sub-wavelength spurious lights are respectively incident on different positions of the first optical switch array 40. The first optical switch array 40 is used to adjust the deflection direction of the incident plurality of sub-wavelength signal lights and the plurality of sub-wavelength spurious lights. The mirror group 2 is for guiding the plurality of sub-wavelength signal lights and the plurality of sub-wavelength spurious lights from the first optical switch array 40 to the second optical switch array 50 to convert the positional difference of the port direction into the angular difference of the port direction. Wherein the sub-wavelength signal light and the sub-wavelength spurious light of the same wavelength are incident on the second optical switch array 50 at the same position but at different angles. The second optical switch array 50 is used to adjust the deflection direction of the incident light at each incident position so that sub-wavelength signal light or sub-wavelength pseudo light of each wavelength is transmitted to the output port 70. Corresponding to the sub-wavelength signal light and sub-wavelength spurious light of each wavelength being alternatively selected by the second optical switch array 50, wherein the selected sub-wavelength signal light or sub-wavelength spurious light is transmitted to the output port 70. The lens group 3 is used to converge sub-wavelength signal light and/or sub-wavelength spurious light from the second optical switch array 50 in the Y direction. The second dispersive element 60 is used for combining sub-wavelength signal light and/or sub-wavelength spurious light from the mirror group 3. The lens group 5 is used for beam shaping and collimating the combined light and redirecting the light to the output port 70.

Fig. 3 (a) is a schematic diagram of the spot distribution of the sub-wavelength signal light and the sub-wavelength spurious light on the first optical switch array. Fig. 3 (b) is a schematic diagram of the spot distribution of the sub-wavelength signal light and the sub-wavelength spurious light on the second optical switch array. As shown in fig. 3 (a), the spot shown by the solid line is the spot of the sub-wavelength signal light, and the spot shown by the broken line is the spot of the sub-wavelength pseudolight. The light spots of the sub-wavelength signal light and the light spots of the sub-wavelength pseudolight are arranged along the Y direction. In the first optical switch array 40, the spot of the sub-wavelength signal light and the spot of the sub-wavelength spurious light have a positional deviation. As shown in fig. 3 (b), on the second optical switch array 50, the spot of the sub-wavelength signal light and the spot of the sub-wavelength spurious light of the same wavelength overlap. It should be understood that, in practical applications, the light spots of the sub-wavelength signal light of the same wavelength and the light spots of the sub-wavelength spurious light may be considered to be identical in incidence position on the second optical switch array 50.

It should be noted that, the first optical switch array 40 and the second optical switch array 50 are controlled by a controller (not shown). The controller performs a wavelength selection function by controlling the first optical switch array 40, i.e., the first optical switch array 40 can direct sub-wavelength signal light and/or sub-wavelength spurious light of a specified wavelength to the second optical switch array 50 by adjusting the deflection direction of the incident light. The controller controls the second optical switch array 50 to select the sub-wavelength signal light and the sub-wavelength spurious light, i.e. the second optical switch array 50 can select the sub-wavelength signal light and the sub-wavelength spurious light with the same wavelength by adjusting the deflection direction of the incident light. It will be appreciated that the first optical switch array 40 has the capability of adjusting in any deflection direction, while the second optical switch array 50 can be switched in only two deflection directions. Therefore, the second optical switch array 50 is adjusted faster relative to the first optical switch array 40, and rapid uploading of signal light and false light can be achieved. As one example, for sub-wavelength signal light and sub-wavelength spurious light of the same wavelength, if the second optical switch array 50 does not change the deflection direction of the incident light, the sub-wavelength signal light is transmitted toward the output port 70; if the second optical switch array 50 changes the deflection direction of the incident light, sub-wavelength pseudo light is transmitted to the output port 70.

In some possible embodiments, if both sub-wavelength signal light and sub-wavelength spurious light of the same wavelength are incident on the second optical switch array 50, the second optical switch array 50 will select to transmit sub-wavelength signal light, i.e. sub-wavelength signal light is transmitted to the output port 70 through the second optical switch array 50. If the sub-wavelength signal light is not incident on the second optical switch array 50 or the energy attenuation of the sub-wavelength signal light is large, the second optical switch array 50 selects to transmit the sub-wavelength spurious light with the same wavelength, that is, the sub-wavelength spurious light is transmitted to the output port 70 through the second optical switch array 50. As an example, the energy of sub-wavelength signal light incident on the second optical switch array 50 may be detected by an optical performance detection (Optical Performance Monitoring, OPM) device. Assuming that the energy attenuation of the first sub-wavelength signal light incident at the first incident position on the second optical switch array 50 is greater than or equal to a preset value, the second optical switch array 50 selects to upload the first sub-wavelength pseudolight having the same wavelength as the first sub-wavelength signal light. Conversely, the second optical switch array 50 selects to upload the first sub-wavelength signal light. The preset value is specifically based on practical application, for example, 5dB, which is not limited herein. It should be appreciated that by detecting the energy of the sub-wavelength signal light incident on the second optical switch array 50, the sub-wavelength signal light and the sub-wavelength spurious light of the same wavelength can be reasonably selected, so that the sub-wavelength signal light of normal transmission can still continue to be transmitted, and the sub-wavelength signal light of abnormal transmission can be uploaded to ensure that the light passing through the WSS is in a full wave state.

It should be noted that the specific types of the first optical switch array 40 and the second optical switch array 50 are not limited in the present application. As one example, the first optical switch array 40 employs liquid crystal on silicon (Liquid Crystal on Silicon, LCOS) and the second optical switch array 50 employs a digital light processor (Digital Light Processer, DLP). It should be appreciated that DLP may also be referred to as a digital micromirror device (Digital Micromirror Device, DMD). The particular types of first dispersive element 30 and second dispersive element 60 are also not limited by the present application. As an example, the first and second dispersive elements 30, 60 may employ gratings, diffractive optical elements (Difractive Optical Element, DOE), or super-surface elements, or the like.

In some possible embodiments, the sub-wavelength signal light or sub-wavelength spurious light may also be attenuated using the WSS shown in fig. 2 (a) and 2 (b) above. It will be appreciated that attenuation is performed by adjusting the deflection direction of the sub-wavelength signal light or sub-wavelength spurious light, in particular by the second optical switch array 50. Before attenuating the sub-wavelength signal light, the sub-wavelength spurious light of the same wavelength needs to be prevented from entering the second optical switch array 50. Because, if both sub-wavelength signal light and sub-wavelength spurious light of the same wavelength are incident on the second optical switch array 50, the sub-wavelength spurious light is enhanced while attenuating the sub-wavelength signal light, affecting the attenuation effect of the sub-wavelength signal light. That is, reducing a portion of the sub-wavelength signal light transmitted to the output port 70 by the second optical switch array 50 correspondingly increases a portion of the sub-wavelength spurious light transmitted to the output port 70, which are in a relationship to each other. Similarly, before attenuating the sub-wavelength spurious light, it is also necessary to prevent the sub-wavelength signal light of the same wavelength from entering the second optical switch array 50. The following detailed description describes specific embodiments respectively.

Embodiment 1: attenuating the sub-wavelength signal light.

The first optical switch array 40 adjusts the deflection direction of the incident second sub-wavelength spurious light such that the second sub-wavelength spurious light is not directed to the second optical switch array 50. The second optical switch array 50 adjusts the deflection direction of the incident second sub-wavelength signal light to attenuate the energy transmitted by the second sub-wavelength signal light toward the output port 70. Wherein the second sub-wavelength signal light has the same wavelength as the second sub-wavelength spurious light.

Embodiment 2: attenuating sub-wavelength spurious light.

The first optical switch array 40 adjusts the deflection direction of the incident third sub-wavelength signal light such that the third sub-wavelength signal light is not directed to the second optical switch array 50. The second optical switch array 50 adjusts the deflection direction of the third sub-wavelength artificial light to attenuate the energy transmitted by the third sub-wavelength artificial light to the output port 70. Wherein the third sub-wavelength signal light has the same wavelength as the third sub-wavelength spurious light.

It should be noted that, the present application is not limited to the above-mentioned modes of composing the lens group 1, the lens group 2, the lens group 3, the lens group 4 and the lens group 5, and a specific implementation is provided below.

As shown in fig. 2 (a) and 2 (b), the lens group 1 includes a lens 1, a lens 2, and a lens 3, the lens group 2 includes a lens 4, a lens 5, and a lens 6, the lens group 3 includes a lens 7 and a lens 8, the lens group 4 includes a lens 9 and a lens 10, and the lens group 5 includes a lens 11 and a lens 12. Specifically, the lens 9 is used for collimating the incident signal light and the spurious light, and the lens 10 is used for beam-shaping the incident signal light and the spurious light. The lens 1 is used for converging multiple sub-wavelength signal lights from the multiple signal light input ports 10 in the X direction, taking 3 signal light input ports 10 as shown in fig. 2 (b) as an example, one sub-wavelength signal light transmitted along the optical axis of the lens 1 is transmitted to the first optical switch array 40 through the lens 1, the other two sub-wavelength signal lights are refracted to the first optical switch array 40 through the lens 1, and the three sub-wavelength signal lights are converged to the same position of the first optical switch array 40 in the X direction. The lens 2 functions similarly to the lens 1 to transmit or refract incident sub-wavelength pseudo light in the X direction so that the sub-wavelength pseudo light incident to the first optical switch array 40 is different from the incident position of the sub-wavelength signal light in the X direction. The lens 3 is used to collimate the incident plurality of sub-wavelength signal lights and the plurality of sub-wavelength pseudolights in the Y direction. The lens 4 is used for converging the incident sub-wavelength signal light and converging the incident sub-wavelength spurious light in the Y direction, the lens 5 is used for converging the incident sub-wavelength signal light and the sub-wavelength spurious light in the X direction, and the lens 6 is used for collimating the incident sub-wavelength signal light and the sub-wavelength spurious light in the Y direction. The lens 7 is for converging the incident sub-wavelength signal light and converging the incident sub-wavelength spurious light in the Y direction, and the lens 8 is for beam shaping the incident sub-wavelength signal light and the sub-wavelength spurious light. The lens 11 is used for beam shaping the light after combining by the second dispersive element 60 and the lens 12 is used for collimating the combined light.

In one possible embodiment, as shown in fig. 2 (a), the front focal plane of lens 10 coincides with the back focal plane of lens 9. The first dispersive element 30 is located at the back focal plane of the lens 10 and at the front focal plane of the lens 3. The first optical switch array 40 is located at the back focal plane of the lens 3 and at the front focal plane of the lens 4. The back focal plane of lens 4 coincides with the front focal plane of lens 6. The second optical switch array 50 is located at the back focal plane of the lens 6 and at the front focal plane of the lens 7. The second dispersive element 60 is located at the back focal plane of the lens 7 and at the front focal plane of the lens 11. Lens 11 is located at the front focal plane of lens 12. As shown in fig. 2 (b), the lens 1 is positioned close to the first dispersive element 30, and the lens 8 is positioned close to the second dispersive element 60. The front focal plane of lens 1 coincides with the back focal plane of lens 9. The first optical switch array 40 is located at the back focal plane of the lens 1. The front focal plane of lens 2 coincides with the back focal plane of lens 9. The first optical switch array 40 is located at the back focal plane of the lens 2. The first optical switch array 40 is located at the front focal plane of the lens 5 and the second optical switch array 50 is located at the back focal plane of the lens 5. The second optical switch array 50 is located at the front focal plane of the lens 8. The back focal plane of lens 8 coincides with the front focal plane of lens 12.

It should be noted that, on the basis of the WSS shown in fig. 2 (a) and 2 (b), the modification may be further performed so that the plurality of sub-wavelength spurious lights from the lens group 1 are directly transmitted to the lens group 2 without passing through the first optical switch array 40. The following description is made with reference to the accompanying drawings.

Fig. 4 (a) is a schematic diagram of a second optical path of the WSS in the dispersion direction in the embodiment of the present application. Fig. 4 (b) is a schematic diagram of a second optical path of the WSS in the port direction in the embodiment of the present application. It should be understood that fig. 4 (a) shows a schematic view of the optical path of the spurious light in the dispersion direction in this embodiment. The beam schematic of the signal light in the dispersion direction in this embodiment is the same as that of fig. 2 (a) described above. As shown in fig. 4 (a) and 4 (b), the sub-wavelength signal light passes through the first optical switch array 40, and the sub-wavelength spurious light does not pass through the first optical switch array 40. In this embodiment, the first optical switch array 40 does not need to adjust the direction of deflection of sub-wavelength spurious light, each of which is incident on the second optical switch array 50. Thus, a first optical switch array 40 of smaller size may be employed, reducing costs. However, this embodiment cannot be applied in a scene where attenuation of sub-wavelength signal light is required. It will be appreciated that this embodiment is similar to the embodiment of fig. 2 (a) and 2 (b) described above except for the differences described above, and that otherwise identical features may be referred to in connection with the embodiment of fig. 2 (a) and 2 (b), and the description will not be repeated here.

As is apparent from the description of the above embodiments, the incident positions of the sub-wavelength signal light and the sub-wavelength spurious light of the same wavelength on the second optical switch array are the same, and the second optical switch array functions to adjust the deflection direction of the incident light at each incident position, so that the sub-wavelength signal light and the sub-wavelength spurious light of each wavelength are selected, and the selected sub-wavelength signal light or sub-wavelength spurious light can be transmitted to the output port. In this way, even if the signal light with a certain wavelength drops in the transmission process, the second optical switch array can select the spurious light with the wavelength to realize the uploading of the spurious light so as to fill the channel of the dropped signal light, thereby maintaining the full wave state, stabilizing the SRS effect and improving the stability of signal transmission. In addition, the second optical switch array is adopted only by switching in two output directions, so that the adjusting speed is higher, and the signal light and the false light can be rapidly uploaded.

The above embodiments introduce one of the WSS structures provided in the present application, mainly by adjusting the incident light deflection direction to select the upload signal light or the dummy light. Another WSS structure provided by the present application will be described below, in which the upload signal light or the pseudolight is selected primarily by adjusting the polarization state of the light.

Fig. 5 (a) is a schematic diagram of a third optical path of the WSS in the dispersion direction in the embodiment of the present application. Fig. 5 (b) is a schematic diagram of a third optical path of the WSS in the port direction in the embodiment of the present application. As shown in fig. 5 (a) and 5 (b), the wavelength selective switch includes: a signal light input port 10, a false light input port 20, a first dispersion element 30, an optical switch array 40, a second dispersion element 60, an output port 70, a first polarization conversion device 80, a second polarization conversion device 90, a polarization beam combiner 100, a polarization conversion array 110, a polarization separator 120, a lens group 1, a lens group 2, and a lens group 3. Wherein the signal light input ports 10 and the dummy light input ports 20 are distributed in the X direction. Optionally, the wavelength selective switch may further comprise a lens group 4 and a lens group 5.

Specifically, the signal light from the signal light input port 10 has components in both the first polarization state and the second polarization state, and the false light from the false light input port 20 has components in both the first polarization state and the second polarization state. Wherein the first polarization state and the second polarization state are orthogonal to each other. The first polarization conversion device 80 is used for converting the signal light from the signal light input port 10 into a first polarization state. The second polarization conversion device 90 is used to convert the spurious light from the spurious light input port 20 to a second polarization state. The lens group 4 is used for first collimating and beam shaping the signal light from the signal light input port 10 and then guiding the signal light to the first dispersing element 30, and first collimating and beam shaping the spurious light from the spurious light input port 20 and then guiding the spurious light to the first dispersing element 30. The first dispersion element 30 is configured to decompose the incident signal light into a plurality of sub-wavelength signal lights in the Y direction and to decompose the incident pseudolight into a plurality of sub-wavelength pseudolights in the Y direction. Wherein the wavelengths of the plurality of sub-wavelength signal lights are different from each other, and the wavelengths of the plurality of sub-wavelength spurious lights are different from each other. The lens group 1 is configured to collimate a plurality of sub-wavelength signal lights and a plurality of sub-wavelength spurious lights in the Y direction, so as to convert an angular difference in the wavelength direction into a position difference in the wavelength direction, wherein the plurality of sub-wavelength signal lights are respectively incident on different positions of the optical switch array 40, and the plurality of sub-wavelength spurious lights are respectively incident on different positions of the optical switch array 40. The optical switch array 40 is used to adjust the deflection direction of the incident plurality of sub-wavelength signal lights and the plurality of sub-wavelength spurious lights. The mirror group 2 is used to guide the plurality of sub-wavelength signal lights and the plurality of sub-wavelength pseudo lights from the optical switch array 40 to the polarization beam combiner 100. The polarization beam combiner 100 is configured to combine the input sub-wavelength signal light and sub-wavelength spurious light, and to guide the combined sub-wavelength signal light and sub-wavelength spurious light to the polarization conversion array 110. Wherein the sub-wavelength signal light and the sub-wavelength spurious light of the same wavelength are incident on the polarization conversion array 110 at the same position. The polarization conversion array 110 is used to adjust the polarization state of the incident light at each incident position to select the polarization state of each sub-wavelength signal light output from the polarization conversion array 110 and the polarization state of each sub-wavelength pseudo light. Wherein the sub-wavelength signal light of the same wavelength output from the polarization conversion array 110 and the sub-wavelength pseudo light have different polarization states. The polarization splitter 120 is configured to transmit the input sub-wavelength signal light and/or sub-wavelength spurious light having the first polarization state and reflect the input sub-wavelength signal light and/or sub-wavelength spurious light having the second polarization state. The lens group 3 is used to collect the sub-wavelength signal light and/or sub-wavelength spurious light transmitted by the polarization splitter 120 in the Y direction. The second dispersive element 60 is used for combining sub-wavelength signal light and/or sub-wavelength spurious light from the mirror group 3. The lens group 5 is used for beam shaping and collimating the combined light and redirecting the light to the output port 70.

In this embodiment, the light spot distribution of the sub-wavelength signal light and the sub-wavelength spurious light on the optical switch array 40 may be as shown in fig. 3 (a), and the light spot distribution of the sub-wavelength signal light and the sub-wavelength spurious light on the polarization conversion array 110 may be as shown in fig. 3 (b). The full overlap or partial overlap of the spots of sub-wavelength signal light and sub-wavelength pseudolight of the same wavelength may be considered as the same location of incidence on the polarization conversion array 110.

It should be noted that, the optical switch array 40 and the polarization conversion array 110 are controlled by a controller (not shown). The controller performs the wavelength selection function by controlling the optical switch array 40, i.e., the optical switch array 40 may direct sub-wavelength signal light and/or sub-wavelength spurious light of a specified wavelength to the polarization conversion array 110 by adjusting the deflection direction of the incident light. The controller performs polarization conversion on the sub-wavelength signal light and the sub-wavelength spurious light of the same wavelength by controlling the polarization conversion array 110, and performs one of the sub-wavelength signal light and the sub-wavelength spurious light of the same wavelength in combination with the polarization separator 120. It should be understood that the polarization conversion array 110 only needs to perform polarization state conversion on the incident light, so that the adjustment speed is faster, and the signal light and the false light can be quickly uploaded. As one example, for sub-wavelength signal light and sub-wavelength spurious light of the same wavelength, if polarization conversion array 110 does not change the polarization state of incident light, the sub-wavelength signal light will be transmitted through polarization splitter 120 to output port 70; if the polarization conversion array 110 changes the polarization state of incident light, sub-wavelength spurious light is transmitted through the polarization splitter 120 to the output port 70.

In some possible embodiments, if both sub-wavelength signal light and sub-wavelength spurious light of the same wavelength are incident on the polarization conversion array 110, the sub-wavelength signal light output from the polarization conversion array 110 will remain in the first polarization state, i.e., the sub-wavelength signal light may be transmitted to the output port 70 through the polarization splitter 120. If the sub-wavelength signal light is not incident on the polarization conversion array 110 or the energy attenuation of the sub-wavelength signal light is large, the polarization conversion array 110 converts the sub-wavelength spurious light of the same wavelength into the first polarization state, that is, the sub-wavelength spurious light may be transmitted to the output port 70 through the polarization splitter 120. As one example, the energy of sub-wavelength signal light incident on the polarization conversion array 110 may be detected by an OPM device. Assuming that the energy attenuation of the first sub-wavelength signal light incident at the first incident position on the polarization conversion array 110 is greater than or equal to a preset value, the first sub-wavelength pseudolight output by the polarization conversion array 110 has a first polarization state. Conversely, the first sub-wavelength signal light output by the second optical switch array 50 remains in the first polarization state. The preset value is specifically based on practical application, for example, 5dB, which is not limited herein. It should be appreciated that by detecting the energy of the sub-wavelength signal light incident on the polarization conversion array 110, the sub-wavelength signal light and the sub-wavelength spurious light with the same wavelength can be reasonably selected, so that the sub-wavelength signal light with normal transmission can still continue to be transmitted, and the sub-wavelength signal light with abnormal transmission can be uploaded with the sub-wavelength spurious light to ensure that the light passing through the WSS is in a full wave state.

It should be noted that the specific types of the optical switch array 40 and the polarization conversion array 110 are not limited in the present application. As one example, optical switch array 40 employs LCOS and polarization conversion array 110 employs ferroelectric liquid crystal on silicon (Ferroelectric Liquid Crystal on Silicon, F-LCOS). The particular types of first dispersive element 30 and second dispersive element 60 are also not limited by the present application. As an example, the first dispersive element 30 and the second dispersive element 60 may employ gratings, DOEs, super surface elements, or the like.

In some possible embodiments, the sub-wavelength signal light or sub-wavelength spurious light may also be attenuated using the WSS shown in fig. 5 (a) and 5 (b) above. It should be appreciated that attenuation is performed by adjusting the polarization state of the sub-wavelength signal light or sub-wavelength pseudolight, in particular, by the polarization conversion array 110. Before attenuating the sub-wavelength signal light, it is also necessary to prevent the same wavelength sub-wavelength spurious light from entering the polarization conversion array 110. Because, if both sub-wavelength signal light and sub-wavelength spurious light of the same wavelength are incident to the polarization conversion array 110, the sub-wavelength spurious light is enhanced while attenuating the sub-wavelength signal light, affecting the attenuation effect of the sub-wavelength signal light. That is, reducing a portion of the sub-wavelength signal light transmitted to output port 70 by polarization conversion array 110 correspondingly increases a portion of the sub-wavelength spurious light transmitted to output port 70, which are in a relationship to one another. Similarly, before attenuating the sub-wavelength spurious light, it is also necessary to prevent the sub-wavelength signal light of the same wavelength from entering the polarization conversion array 110. The following detailed description describes specific embodiments respectively.

Embodiment 1: attenuating the sub-wavelength signal light.

The optical switch array 40 adjusts the deflection direction of the incident second sub-wavelength spurious light such that the second sub-wavelength spurious light is not directed to the polarization beam combiner 100. Polarization conversion array 110 adjusts the polarization state of the incident second sub-wavelength signal light to attenuate the energy transmitted by the second sub-wavelength signal light toward output port 70. Wherein the second sub-wavelength signal light has the same wavelength as the second sub-wavelength spurious light.

Embodiment 2: attenuating sub-wavelength spurious light.

The optical switch array 40 adjusts the deflection direction of the incident third sub-wavelength signal light such that the third sub-wavelength signal light is not directed to the polarization beam combiner 100. Polarization conversion array 110 adjusts the direction of deflection of the third sub-wavelength pseudolight to attenuate the energy transmitted by the third sub-wavelength pseudolight to output port 70. Wherein the third sub-wavelength signal light has the same wavelength as the third sub-wavelength spurious light.

As shown in fig. 5 (a) and 5 (b), the lens group 1 includes a lens 1, a lens 2, and a lens 3, the lens group 2 includes a lens 4, a lens 5, a lens 6, a lens 13, and a mirror, the lens group 3 includes a lens 7 and a lens 8, the lens group 4 includes a lens 9 and a lens 10, and the lens group 5 includes a lens 11 and a lens 12. Specifically, the lens 9 is used for collimating the incident signal light and the spurious light, and the lens 10 is used for beam-shaping the incident signal light and the spurious light. The lens 1 is used for converging multiple sub-wavelength signal lights from the multiple signal light input ports 10 in the X direction, taking 3 signal light input ports 10 as shown in fig. 5 (b) as an example, one sub-wavelength signal light transmitted along the optical axis of the lens 1 is transmitted to the optical switch array 40 through the lens 1, the other two sub-wavelength signal lights are refracted to the optical switch array 40 through the lens 1, and the three sub-wavelength signal lights are converged to the same position of the optical switch array 40 in the X direction. The lens 2 functions similarly to the lens 1 for transmitting or refracting the incident sub-wavelength pseudo light in the X direction so that the sub-wavelength pseudo light incident to the optical switch array 40 is different from the incident position of the sub-wavelength signal light in the X direction. The lens 3 is used to collimate the incident plurality of sub-wavelength signal lights and the plurality of sub-wavelength pseudolights in the Y direction. The lens 4 is used for converging the incident sub-wavelength signal light in the Y direction and converging the incident sub-wavelength spurious light, the lens 5 is used for beam shaping the incident sub-wavelength signal light, and the lens 6 is used for collimating the incident sub-wavelength signal light in the Y direction. The lens 13 is used to beam-shape the incident sub-wavelength spurious light and the mirror is used to reflect the sub-wavelength spurious light from the lens 13 to the polarization beam combiner 100. The lens 7 is for converging the incident sub-wavelength signal light and converging the incident sub-wavelength spurious light in the Y direction, and the lens 8 is for beam shaping the incident sub-wavelength signal light and the sub-wavelength spurious light. The lens 11 is used for beam shaping the light after combining by the second dispersive element 60 and the lens 12 is used for collimating the combined light.

In one possible embodiment, as shown in fig. 5 (a), the front focal plane of lens 10 coincides with the back focal plane of lens 9. The first dispersive element 30 is located at the back focal plane of the lens 10 and at the front focal plane of the lens 3. The optical switch array 40 is located at the back focal plane of the lens 3 and at the front focal plane of the lens 4. The back focal plane of lens 4 coincides with the front focal plane of lens 6. The polarization conversion array 110 is located at the back focal plane of the lens 6 and at the front focal plane of the lens 7. The second dispersive element 60 is located at the back focal plane of the lens 7 and at the front focal plane of the lens 11. Lens 11 is located at the front focal plane of lens 12. As shown in fig. 5 (b), the lens 1 is positioned close to the first dispersive element 30, and the lens 8 is positioned close to the second dispersive element 60. The front focal plane of lens 1 coincides with the back focal plane of lens 9. The optical switch array 40 is located at the back focal plane of the lens 1. The front focal plane of lens 2 coincides with the back focal plane of lens 9. The optical switch array 40 is located at the back focal plane of the lens 2. The optical switch array 40 is located at the front focal plane of the lens 5 and the second optical switch array 50 is located at the back focal plane of the lens 5. The optical switch array 40 is located at the front focal plane of the lens 13 and the second optical switch array 50 is located at the back focal plane of the lens 13. The polarization conversion array 110 is located at the front focal plane of the lens 8. The back focal plane of lens 8 coincides with the front focal plane of lens 12.

It should be noted that, on the basis of the WSS shown in fig. 5 (a) and 5 (b), the modification may be further performed so that the plurality of sub-wavelength spurious lights from the lens group 1 are directly transmitted to the lens group 2 without passing through the optical switch array 40. The following description is made with reference to the accompanying drawings.

Fig. 6 (a) is a schematic diagram of a fourth optical path of the WSS in the dispersion direction in the embodiment of the present application. Fig. 6 (b) is a schematic diagram of a fourth optical path of the WSS in the port direction in the embodiment of the present application. It should be understood that fig. 6 (a) shows a schematic view of the optical path of the spurious light in the dispersion direction in the present embodiment. The beam schematic of the signal light in the dispersion direction in this embodiment is the same as that of fig. 5 (a) described above. As shown in fig. 6 (a) and 6 (b), sub-wavelength signal light passes through the optical switch array 40, and sub-wavelength spurious light does not pass through the optical switch array 40. In this embodiment, the optical switch array 40 does not need to adjust the direction of deflection of sub-wavelength spurious light, each of which is incident on the polarization beam combiner 100. Thus, a smaller size optical switch array 40 may be used, reducing costs. However, this embodiment cannot be applied in a scene where attenuation of sub-wavelength signal light is required. It will be appreciated that this embodiment is similar to the embodiment of fig. 5 (a) and 5 (b) described above except for the differences described above, and that otherwise identical features may be referred to in connection with the embodiment of fig. 5 (a) and 5 (b), and the description will not be repeated here.

As is apparent from the description of the above embodiments, the incident positions of the sub-wavelength signal light and the sub-wavelength spurious light of the same wavelength on the polarization conversion array are the same, and the polarization conversion array is used to adjust the polarization state of the incident light at each incident position, and the polarization separator is combined to perform a selection between the sub-wavelength signal light and the sub-wavelength spurious light of each wavelength, so that the selected sub-wavelength signal light or sub-wavelength spurious light can be transmitted to the output port. In this way, even if the signal light with a certain wavelength drops in the transmission process, the spurious light with the certain wavelength can be selected by the polarization conversion array and the deflection separator to upload the spurious light so as to fill the channel of the dropped signal light, thereby maintaining the full wave state, stabilizing the SRS effect and improving the stability of signal transmission. In addition, the polarization conversion array is adopted, only the incident light needs to be converted between two polarization states, the adjusting speed is higher, and the signal light and the false light can be rapidly uploaded.

It should be noted that, the embodiments provided above are described with reference to the transmissive optical switch array 40. In some possible embodiments, a reflective optical switch array 40 may also be employed. That is, the output port 70 in the WSS is located on the same side as the signal light input port 10 and the dummy light input port 20, and a folded optical path is employed. It should be appreciated that embodiments employing reflective optical switch arrays 40 may be readily adapted based on the above examples, and that the illustrations and descriptions are not provided herein.

It should be noted that the above embodiments are only for illustrating the technical solution of the present application, and are not limiting. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions.

Claims

1. A wavelength selective switch WSS, comprising: the optical fiber comprises a signal light input port, a false light input port, an output port, a first dispersion element, a second dispersion element, a first optical switch array, a second optical switch array, a first lens group, a second lens group and a third lens group, wherein the signal light input port and the false light input port are distributed along a first direction;

the first dispersion element is used for decomposing the signal light from the signal light input port into a plurality of sub-wavelength signal lights in a second direction, and decomposing the false light from the false light input port into a plurality of sub-wavelength false lights in the second direction, and the second direction is perpendicular to the first direction;

The first lens group is used for collimating the plurality of sub-wavelength signal lights and the plurality of sub-wavelength false lights in the second direction;

the first optical switch array is used for adjusting the deflection directions of a plurality of sub-wavelength signal lights from the first lens;

the second lens group is used for guiding the sub-wavelength signal light from the first optical switch array and the sub-wavelength false light from the first lens group to the second optical switch array, wherein the incidence positions of the sub-wavelength signal light and the sub-wavelength false light with the same wavelength on the second optical switch array are the same;

the second optical switch array is used for adjusting the deflection direction of the incident light at each incident position so as to enable sub-wavelength signal light or sub-wavelength pseudo light of each wavelength to be transmitted to the output port;

the third lens group is used for converging sub-wavelength signal light and/or sub-wavelength false light from the second optical switch array in the second direction;

the second dispersion element is used for combining sub-wavelength signal light and/or sub-wavelength false light from the third lens group and guiding the combined light to the output port.

2. The WSS of claim 1, wherein if an energy attenuation of a first sub-wavelength signal light incident at a first incident location on the second optical switch array is greater than or equal to a preset value, then transmitting the first sub-wavelength spurious light incident at the first incident location through the second optical switch array to the output port;

And if the energy attenuation of the first sub-wavelength signal light incident at the first incident position on the second optical switch array is smaller than the preset value, transmitting the first sub-wavelength signal light to the output port through the second optical switch array.

3. A WSS according to claim 1 or 2, wherein a plurality of sub-wavelength spurious light from the first set of mirrors is transmitted through the first array of optical switches to the second set of mirrors.

4. A WSS according to claim 3, wherein the first optical switch array is further configured to adjust a deflection direction of a second sub-wavelength spurious light from the first set of mirrors, wherein the second sub-wavelength spurious light with the adjusted deflection direction is not directed to the second optical switch array;

the second optical switch array is used for adjusting the deflection direction of the second sub-wavelength signal light from the second lens group so as to attenuate the energy transmitted by the second sub-wavelength signal light to the output port, and the second sub-wavelength spurious light is the same as the wavelength of the second sub-wavelength signal light.

5. A WSS according to any one of claims 1 to 4, wherein third sub-wavelength signal light is not directed to said second optical switch array after being deflected by said first optical switch array;

The second optical switch array is configured to adjust a deflection direction of third sub-wavelength spurious light from the second lens group to attenuate energy transmitted by the third sub-wavelength spurious light to the output port, where the third sub-wavelength spurious light is the same wavelength as the third sub-wavelength signal light.

6. The WSS according to any one of claims 1 to 5, further comprising a fourth lens group and a fifth lens group;

the fourth lens group is used for collimating and beam shaping the signal light from the signal light input port and guiding the signal light to the first dispersing element, and collimating and beam shaping the spurious light from the spurious light input port and guiding the spurious light to the first dispersing element;

the fifth mirror group is used to first collimate and beam-shape the combined light from the second dispersive element and redirect the collimated light to the output port.

7. The WSS according to any one of claims 1 to 6, wherein the first lens group comprises a first lens, a second lens, and a third lens;

the first lens is configured to transmit the plurality of sub-wavelength signal lights from the first dispersion element or to refract the plurality of sub-wavelength signal lights from the first dispersion element in the first direction;

The second lens is used for transmitting the plurality of sub-wavelength false lights from the first dispersing element or refracting the plurality of sub-wavelength false lights from the first dispersing element in the first direction;

the third lens is configured to collimate the plurality of sub-wavelength signal lights from the first lens in the second direction and to collimate the plurality of sub-wavelength spurious lights from the second lens.

8. The WSS according to any one of claims 1 to 7, wherein the second lens group comprises a fourth lens, a fifth lens, and a sixth lens;

the fourth lens is used for converging the sub-wavelength signal light from the first optical switch array in the second direction and converging the sub-wavelength false light from the first lens group;

the fifth lens is used for converging the sub-wavelength signal light and the sub-wavelength false light from the fourth lens in the first direction;

the sixth lens is used for collimating the sub-wavelength signal light and the sub-wavelength false light from the fifth lens in the second direction and guiding the sub-wavelength signal light and the sub-wavelength false light to the second optical switch array.

9. A WSS according to any one of claims 1 to 8, wherein the third lens group comprises a seventh lens and an eighth lens;

The seventh lens is used for converging the sub-wavelength signal light from the second optical switch array in the second direction and converging the sub-wavelength false light from the second optical switch array;

the eighth lens is used for carrying out beam shaping on the sub-wavelength signal light and the sub-wavelength false light from the seventh lens.

10. The WSS according to any one of claims 1 to 9, wherein the first optical switch array is a liquid crystal on silicon LCOS and the second optical switch array is a digital light processor DLP.

11. A WSS according to any one of claims 1 to 10, further comprising a controller, wherein the first and second arrays of optical switches are controlled by the controller.

12. A wavelength selective switch WSS, comprising: the optical fiber comprises a signal light input port, a false light input port, an output port, a first dispersion element, a second dispersion element, an optical switch array, a first polarization conversion device, a second polarization conversion device, a polarization beam combiner, a polarization conversion array, a polarization separator, a first lens group, a second lens group and a third lens group, wherein the signal light input port and the false light input port are distributed along a first direction;

The first polarization conversion device is used for converting the signal light from the signal light input port into a first polarization state;

the second polarization conversion device is used for converting the false light from the false light input port into a second polarization state, and the first polarization state and the second polarization state are mutually orthogonal;

the first dispersing element is used for decomposing the signal light from the first polarization conversion device into a plurality of sub-wavelength signal lights in a second direction, and decomposing the false light from the second polarization conversion device into a plurality of sub-wavelength false lights in the second direction, and the second direction is perpendicular to the first direction;

the optical switch array is used for adjusting the deflection directions of a plurality of sub-wavelength signal lights from the first lens;

the second lens group is used for guiding the sub-wavelength signal light from the optical switch array and the sub-wavelength false light from the first lens group to the polarization beam combiner;

the polarization beam combiner is used for combining the sub-wavelength signal light from the second lens group and the sub-wavelength false light, and guiding the combined sub-wavelength signal light and sub-wavelength false light to the polarization conversion array, wherein the incidence positions of the sub-wavelength signal light and sub-wavelength false light with the same wavelength on the polarization conversion array are the same;

The polarization conversion array is used for adjusting the polarization state of incident light at each incident position so as to select the polarization state of each sub-wavelength signal light output from the polarization conversion array and the polarization state of each sub-wavelength artificial light, wherein the polarization states of sub-wavelength signal light and sub-wavelength artificial light of the same wavelength output from the polarization conversion array are different;

the polarization separator is used for transmitting sub-wavelength signal light and/or sub-wavelength false light with a first polarization state from the polarization conversion array and reflecting sub-wavelength signal light and/or sub-wavelength false light with a second polarization state from the polarization conversion array;

the third lens group is used for converging the sub-wavelength signal light and/or sub-wavelength false light transmitted by the polarization separator in the second direction;

13. The WSS of claim 12, wherein if the energy attenuation of the first sub-wavelength signal light incident at the first incident location on the polarization conversion array is greater than or equal to a preset value, the first sub-wavelength spurious light incident at the first incident location has a first polarization state after passing through the polarization conversion array, and the first sub-wavelength signal light has a second polarization state after passing through the polarization conversion array;

If the energy attenuation of the first sub-wavelength signal light incident at the first incident position on the second optical switch array is smaller than the preset value, the first sub-wavelength false light has a second polarization state after passing through the polarization conversion array, and the first sub-wavelength signal light has a first polarization state after passing through the polarization conversion array.

14. A WSS according to claim 12 or 13, wherein a plurality of sub-wavelength spurious light from the first set of mirrors is transmitted through the optical switch array to the second set of mirrors.

15. The WSS of claim 14 wherein said optical switch array is further configured to adjust a direction of deflection of second sub-wavelength spurious light from said first set of mirrors, wherein said second sub-wavelength spurious light with the direction of deflection adjusted is not directed to said polarization beam combiner;

the polarization conversion array is used for adjusting the polarization state of second sub-wavelength signal light from the polarization beam combiner so as to attenuate the energy transmitted by the second sub-wavelength signal light to the output port, wherein the second sub-wavelength false light has the same wavelength as the second sub-wavelength signal light.

16. A WSS according to any one of claims 12 to 14 wherein third sub-wavelength signal light is not directed to the polarizing beam combiner after being deflected by the optical switch array;

The polarization conversion array is used for adjusting the polarization state of third sub-wavelength pseudo light from the polarization beam combiner to attenuate the energy transmitted by the third sub-wavelength pseudo light to the output port, wherein the wavelength of the third sub-wavelength pseudo light is the same as that of the third sub-wavelength signal light.

17. A WSS according to any one of claims 12 to 16, further comprising a fourth lens group and a fifth lens group;

the fourth lens group is used for collimating and beam shaping the signal light from the signal light input port and guiding the signal light to the first polarization conversion device, and collimating and beam shaping the spurious light from the spurious light input port and guiding the spurious light to the first polarization conversion device;

18. A WSS according to any one of claims 12 to 17, wherein the first lens group comprises a first lens, a second lens and a third lens;

19. A WSS according to any one of claims 12 to 18 wherein the second lens group comprises a fourth lens, a fifth lens, a sixth lens, a seventh lens and a mirror;

the fourth lens is used for converging the sub-wavelength signal light from the optical switch array in the second direction and converging the sub-wavelength false light from the first lens group;

the fifth lens is used for carrying out beam shaping on the sub-wavelength signal light from the fourth lens;

the sixth lens is used for collimating the sub-wavelength signal light from the fifth lens in the second direction and guiding the sub-wavelength signal light to the polarization beam combiner;

the seventh lens is used for carrying out beam shaping on the sub-wavelength false light from the fourth lens;

The reflector is used for reflecting the sub-wavelength spurious light from the seventh lens to the polarization beam combiner.

20. A WSS according to any one of claims 12 to 19, wherein the third lens group comprises an eighth lens and a ninth lens;

the eighth lens is used for converging the sub-wavelength signal light from the polarization separator in the second direction and converging the sub-wavelength false light from the polarization separator;

the ninth lens is used for carrying out beam shaping on the sub-wavelength signal light and the sub-wavelength false light from the eighth lens.

21. A WSS according to any one of claims 12 to 20, wherein the optical switch array is a liquid crystal on silicon LCOS and the polarization conversion array is a ferroelectric liquid crystal on silicon F-LCOS.

22. A WSS according to any one of claims 12 to 21, further comprising a controller, wherein the optical switch array and the polarization conversion array are controlled by the controller.