Method for controlling output frequency of wavelength selective switch, and wavelength selective switch

Abstract

The present invention relates to the technical field of optics, and in particular to a method for controlling the output frequency of a wavelength selective switch, and a wavelength selective switch. In the present invention, the method comprises: acquiring a shared pixel column between adjacent first and second channels on a wavelength distribution diagram of an LCOS chip; calculating a first ratio of the first channel occupying the shared pixel column, and a second ratio of the second channel occupying the shared pixel column; and finally, allocating pixels in the shared pixel column to the first channel and the second channel respectively on the basis of the first ratio and the second ratio. The bandwidths of the first channel and the second channel can be balanced, and the two channels each obtain a required bandwidth while sharing the pixels. Existing frequency adjustment precision is approximately 6.25 GHz, while the frequency adjustment precision of the present solution can reach 0.5 GHz, thereby achieving more precise frequency adjustment and reducing noise and distortion in signals. Even when an external environment changes, precise frequency control can be maintained, thereby significantly improving system stability.

Description

A method for controlling the output frequency of a wavelength selective switch and the wavelength selective switch itself.

[0001] Cross-reference of related applications

[0002] This application claims priority to the following patent application:

[0003] (1) A Chinese patent application filed on August 29, 2024, with application number 202411201696.4, entitled “A method for controlling the output frequency of a wavelength selective switch and a wavelength selective switch”. Technical Field

[0004] This invention relates to the field of optical technology, and in particular to a method for controlling the output frequency of a wavelength selective switch and a wavelength selective switch. Background Technology

[0005] With the development of wavelength division multiplexing (WDM) systems, people have increasingly higher requirements for system flexibility. Wavelength selective switches (WSS) are optical devices that can attenuate, switch, or block any wavelength or wavelength combination at any output port. Coupled with their precise optical power attenuation control function, they have become key components of reconfigurable optical add-drop multiplexer (ROADM) systems and have been widely used in intelligent optical networks.

[0006] A waveguide-based optical signal controller (WSS) consists of basic optical coupling elements and a core optical chip. Currently, the core optical chip is primarily based on Liquid Crystal on Silicon (LCOS). In existing technology, the frequency control precision for WSS is generally approximately equivalent to that of a single pixel in an LCOS chip, around 6.25 GHz. In dense waveguide or fiber optic communication systems, finer bandwidth adjustment precision is required to transmit multiple signals simultaneously within the fiber. Insufficient frequency control precision may prevent the achievement of the necessary channel spacing, thus limiting system capacity and failing to meet the demands of high-precision WSS applications.

[0007] Therefore, overcoming the shortcomings of the existing technology is an urgent problem to be solved in this technical field.

[0008] Application content

[0009] The technical problem to be solved by this invention is how to improve the frequency control accuracy of wavelength selective switches.

[0010] The present invention adopts the following technical solution:

[0011] Firstly, a method for controlling the output frequency of a wavelength selective switch is provided. This method controls the output frequency of a wavelength selective switch based on an LCOS chip, including:

[0012] Obtain the shared pixel column between adjacent first and second channels on the wavelength distribution map of the LCOS chip;

[0013] Obtain a first proportion of the first channel occupying the shared pixel column, and a second proportion of the second channel occupying the shared pixel column;

[0014] The pixels in the shared pixel column are assigned to the first channel and the second channel respectively according to the first ratio and the second ratio, and the phase of each pixel in the shared pixel column is configured according to the channel to which the pixel belongs.

[0015] Preferably, obtaining the shared pixel column between adjacent first and second channels on the wavelength distribution map of the LCOS chip includes:

[0016] The frequency ranges of the first channel and the second channel are preset respectively, and the common frequency at the common point of the two channels is obtained according to the corresponding frequency range;

[0017] The pixel column in which the shared frequency is located is obtained according to the pre-stored frequency table, and the obtained pixel column is the shared pixel column.

[0018] Preferably, obtaining the first proportion of the first channel occupying the shared pixel column and the second proportion of the second channel occupying the shared pixel column includes:

[0019] The first frequency of the pixel column adjacent to the shared pixel column in the first channel is obtained according to the pre-stored frequency table;

[0020] The second frequency of the pixel column adjacent to the shared pixel column in the second channel is obtained according to the pre-stored frequency table;

[0021] The first ratio and the second ratio are calculated based on the shared frequency, the first frequency, and the second frequency.

[0022] Preferably, the first ratio is calculated as follows: λ2=1-λ1

[0023] Wherein, λ1 is the first ratio, λ2 is the second ratio, f is the shared frequency, f(j) is the first frequency, and f(j+1) is the second frequency.

[0024] Preferably, the step of allocating pixels in the shared pixel column to the first channel and the second channel respectively according to the first ratio and the second ratio, and configuring the phase of each pixel in the shared pixel column according to the channel to which the pixel belongs includes:

[0025] Obtain the total number of pixels in the shared pixel column, and obtain the first phase distribution map corresponding to the first channel and the second phase distribution map corresponding to the second channel;

[0026] In the shared pixel column, a unique marker is added to each pixel from bottom to top;

[0027] In the shared pixel column, a first proportion of pixels from the total number of pixels are taken from bottom to top, and the phase of the obtained pixels is configured using the first phase distribution map and the unique marker corresponding to each pixel;

[0028] The phase of the remaining pixels is configured using the second phase distribution map and the unique marker corresponding to each pixel.

[0029] Preferably, the step of allocating pixels in the shared pixel column to the first channel and the second channel respectively according to the first ratio and the second ratio, and configuring the phase of each pixel in the shared pixel column according to the channel to which the pixel belongs, further includes:

[0030] Obtain the total number of pixels in the shared pixel column, and obtain the first phase distribution map corresponding to the first channel and the second phase distribution map corresponding to the second channel;

[0031] In the shared pixel column, a unique marker is added to each pixel from bottom to top;

[0032] In the shared pixel column, at each preset number of pixels, a first proportion of the total number of pixels are taken from bottom to top, and the phase of the obtained pixels is configured by the first phase distribution map and the unique label corresponding to each pixel;

[0033] The phase of the remaining pixels is configured using the second phase distribution map and the unique marker corresponding to each pixel.

[0034] Preferably, configuring the phase of the acquired pixels using the first phase distribution map and the unique marker corresponding to each pixel includes:

[0035] The abscissa of the first phase distribution map is mapped one-to-one with the unique marker corresponding to each pixel to configure the phase of each acquired pixel; the configuration of the phase of the remaining pixels using the second phase distribution map and the unique marker corresponding to each pixel includes:

[0036] The horizontal coordinates of the second phase distribution map are mapped one-to-one with the unique marker corresponding to each pixel to configure the phase of each remaining pixel. Preferably, the control method further includes:

[0037] The frequency variation of the wavelength selection switch under different temperature and pressure environments was calibrated using temperature and pressure sensors.

[0038] The output frequency of the wavelength selection switch is dynamically compensated based on the frequency change to control the output frequency of the wavelength selection switch.

[0039] In a second aspect, a wavelength selective switch is provided, comprising: an LCOS chip 210 and at least three collimators 201, wherein the LCOS chip 210 is coupled to the at least three collimators 201;

[0040] At least one of the collimators 201 is used to receive incident light including at least two wavelengths, and at least two of the collimators 201 are used to output outgoing light of different wavelengths respectively.

[0041] The LCOS chip 210 is used to change the transmission direction of the incident light and obtain at least two different wavelengths of the outgoing light. The phase of each pixel in the common pixel column on the LCOS chip (210) is configured according to the control method of the output frequency of the wavelength selection switch as described in any one of claims 1-8.

[0042] Preferably, the wavelength selection switch further includes a grating 205, which is located between the at least three collimators 201 and the LCOS chip 210, and is coupled to the at least three collimators 201 and the LCOS chip 210 respectively; the grating 205 is used to diffract and split the incident light to form corresponding light spots, and the light spots cover different areas on the surface of the LCOS chip 210 respectively.

[0043] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0044] This invention obtains the shared pixel column between adjacent first and second channels on the wavelength distribution map of an LCOS chip, calculates a first proportion of the shared pixel column occupied by the first channel, and a second proportion of the shared pixel column occupied by the second channel, and finally allocates the pixels in the shared pixel column to the first and second channels respectively according to the first and second proportions. This balances the bandwidth of the first and second channels, allowing each channel to obtain the required bandwidth while sharing pixels, thus meeting specific frequency width requirements. Secondly, while existing frequency adjustment accuracy is approximately 6.25 GHz, this solution achieves an accuracy of 0.5 GHz, enabling finer frequency adjustment and reducing noise and distortion in the signal. Furthermore, it maintains precise frequency control even when the external environment changes, significantly improving system stability. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 is a flowchart illustrating a frequency control method for a wavelength selective switch provided in an embodiment of the present invention;

[0047] Figure 2 is a schematic diagram of the wavelength distribution of an LCOS chip provided in an embodiment of the present invention;

[0048] Figure 3 is a phase distribution diagram of an LCOS chip provided in an embodiment of the present invention;

[0049] Figure 4 is a phase distribution diagram of another LCOS chip provided in an embodiment of the present invention;

[0050] Figure 5 is a combined phase distribution diagram of an LCOS chip provided in an embodiment of the present invention;

[0051] Figure 6 is a combined phase distribution diagram of another LCOS chip provided in an embodiment of the present invention;

[0052] Figure 7 illustrates another frequency control method for a wavelength selective switch provided in an embodiment of the present invention.

[0053] Figure 8 is an optical schematic diagram of a wavelength selective switch based on an LCOS chip provided in an embodiment of the present invention;

[0054] Figure 9 is a schematic diagram of the y-direction of a wavelength selection switch based on an LCOS chip provided in an embodiment of the present invention;

[0055] Figure 10 is a schematic diagram of the x-direction of a wavelength selection switch based on an LCOS chip provided in an embodiment of the present invention. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0057] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as openly inclusive, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples; that is, although they may be incorporated into embodiments or examples using the above terms for reasons such as order and position, it does not limit them to be incorporated in combination by a single embodiment or example.

[0058] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more. Furthermore, for example, the description may use the prefix "A" or "B" to describe the same type of nouns as two independent entities. In this case, the corresponding features defined with "A" and "B" are used only to distinguish between similar entities and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features.

[0059] In describing some embodiments, the terms "coupled," "coupled," and "connected," and their derivative expressions, may be used. For example, the term "connected" may be used in describing some embodiments to indicate that two or more components have direct physical or electrical contact with each other. Similarly, the term "coupled" may be used in describing some embodiments to indicate that two or more components have direct physical or electrical contact. However, the terms "connected" or "coupled" may also refer to two or more components that do not have direct contact with each other but still cooperate or interact with each other, such as "optical coupling," "wireless connection," etc. The embodiments disclosed herein are not necessarily limited to the scope of this invention.

[0060] Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0061] Example 1:

[0062] In a WSS based on an LCOS chip, different wavelengths of light from the WSS are sequentially distributed across different regions of the LCOS chip. When a user sets a channel, a corresponding area is defined on the LCOS chip. Generally, the left and right edges of a channel are not exactly between two pixels; they are usually located in the middle of a column of pixels, occupying a certain proportion of that column. Therefore, if the entire column of pixels corresponding to these edges is used, it will occupy the frequency space of adjacent channels, increasing the bandwidth of the current channel while decreasing the bandwidth of adjacent channels. Conventional control methods typically only allow for bandwidth control precision down to one pixel (approximately 6.25 GHz), which is insufficient for high-precision wavelength selective switching applications.

[0063] To meet the requirements of high-precision wavelength selective switches, this embodiment proposes a method for controlling the output frequency of a wavelength selective switch. The method controls the output frequency of a wavelength selective switch based on an LCOS chip, including: obtaining a shared pixel column between adjacent first and second channels on the wavelength distribution map of the LCOS chip; obtaining a first proportion of the first channel occupying the shared pixel column and a second proportion of the second channel occupying the shared pixel column; allocating pixels in the shared pixel column to the first and second channels respectively according to the first and second proportions; and configuring the phase of each pixel in the shared pixel column according to the channel to which the pixel belongs, thereby allocating the bandwidth of the first and second channels.

[0064] First, it's necessary to obtain information about the wavelength distribution map on the LCOS chip, typically involving the intensity distribution of light signals of different wavelengths on the chip. In an LCOS chip, different channels may share some pixels. The proportion of the shared pixel column occupied by each channel is calculated. Based on the proportions of the shared pixel column occupied by the two channels, these pixels are allocated to the corresponding channels. In this way, the output bandwidth of each channel can be controlled. For example, if the first proportion of the shared pixel column occupied by the first channel is calculated to be 50%, and the second proportion is calculated to be 50%, then the two channels will equally divide the pixels in the shared pixel column. Through the above pixel allocation, the frequency distribution of the WSS output port can be adjusted, thereby achieving control of the output frequency. The specific calculation methods for the first and second proportions, and how to allocate the pixels on the shared pixel column to the two channels based on the first and second proportions, will be explained in detail below.

[0065] The method for controlling the output frequency will be explained in detail below.

[0066] In one embodiment, as shown in FIG1, the method for controlling the output frequency includes:

[0067] Step 101: Obtain the shared pixel column between adjacent first and second channels on the wavelength distribution map of the LCOS chip.

[0068] Among them, the first channel and the second channel are two adjacent wavelength selection channels.

[0069] In one embodiment, as shown in FIG2, the first channel is the region between boundary line 211 and boundary line 212, and the second channel is the region between boundary line 212 and boundary line 213. The shared pixel column between the first channel and the second channel is the column of pixels located at boundary line 212.

[0070] Step 101 specifically includes: presetting the frequency ranges of the first channel and the second channel respectively, and obtaining the common frequency at the common point of the two channels according to the corresponding frequency range; obtaining the pixel column where the common frequency is located according to the pre-stored frequency table, wherein the obtained pixel column is the common pixel column.

[0071] On the wavelength distribution map of the LCOS chip, each column of pixels is a period, and each period corresponds to a frequency. Since the frequency is continuous, the frequency range in the first channel can be F1-F2, and the frequency range in the second channel can be F2-F3. Since the two channels share a common frequency F2, the column of pixels corresponding to frequency F2 can be found in the pre-stored frequency table of the LCOS chip stored in the WSS. The obtained column of pixels is the shared column of pixels, which is the column of squares where the dividing line 212 in Figure 2 is located.

[0072] It is worth noting that the frequency range of the two channels is designed by the user according to the needs of each channel. Therefore, after obtaining the common pixel column, and then allocating the common pixel column according to the following steps, the frequency width of the two channels can be kept consistent with the user setting, thereby achieving the purpose of frequency control.

[0073] Step 102: Obtain the first proportion of the first channel occupying the shared pixel column, and the second proportion of the second channel occupying the shared pixel column.

[0074] In one embodiment, step 102 specifically includes: obtaining a first frequency of a pixel column adjacent to the shared pixel column in the first channel according to the pre-stored frequency table; obtaining a second frequency of a pixel column adjacent to the shared pixel column in the second channel according to the pre-stored frequency table; and calculating a first ratio and a second ratio based on the shared frequency, the first frequency, and the second frequency.

[0075] In one embodiment, the first ratio is calculated as follows: λ2=1-λ1

[0076] Wherein, λ1 is the first ratio, λ2 is the second ratio, f is the shared frequency, f(j) is the first frequency, and f(j+1) is the second frequency.

[0077] In one embodiment, in Figure 2, let the common frequency of the shared pixel column be f, the pixel column number with a frequency less than or equal to f be j (i.e., the pixel column adjacent to the shared pixel column in the first channel), and the column number with a frequency greater than or equal to f be j+1 (i.e., the pixel column adjacent to the shared pixel column in the second channel). The frequency values ​​corresponding to these two columns are f(j) and f(j+1), respectively. Then there exists an inequality f(j)≤f≤f(j+1). Therefore, the first proportion λ1 of the shared pixel column occupied by the first channel is λ1=(ff(j)) / (f(j+1)-f(j)), and the second proportion λ2 of the shared pixel column occupied by the second channel is λ2=1-λ1.

[0078] Step 103: Assign the pixels in the shared pixel column to the first channel and the second channel respectively according to the first ratio and the second ratio, and configure the phase of each pixel in the shared pixel column according to the channel to which the pixel belongs.

[0079] In this embodiment, the phase of each pixel in the shared pixel column is configured according to the phase distribution map of the channel to which the pixel belongs.

[0080] Among them, the phase distribution diagram refers to the position distribution diagram of the light wave at a specific moment in its cycle. It is a scale for whether the light wave is at a peak, trough or a point in between. When light is transmitted in the transmission medium, it is transmitted in a continuous reflection manner at a certain incident angle. The light wave changes in a periodic manner. When the waveform of the light wave completes one cycle, the corresponding angle is 360°, which is also the corresponding radian is 2π.

[0081] More precisely, the phase distribution map of each channel is the phase distribution map of the non-shared pixel column, which reflects the phase of each pixel in that column. A non-shared pixel column refers to a pixel column that belongs only to one channel (the first channel or the second channel) and is not shared by other channels. The phase distribution map of each non-shared pixel column in each channel is identical. Figure 3 shows the phase distribution map of each non-shared pixel column in the first channel (i.e., 301); Figure 4 shows the phase distribution map of each non-shared pixel column in the second channel (i.e., 302).

[0082] In one embodiment, the horizontal axis of the phase distribution map is the marker of each pixel corresponding to the corresponding channel along the Y-axis direction in the wavelength distribution map (i.e., corresponding to each rectangular square in Figure 2); the vertical axis represents the phase value corresponding to each pixel, i.e., the phase ranges from 0 to 2π.

[0083] Taking Figures 2 and 3 as examples, in Figure 2, each column of pixels includes 40 pixels, and each pixel corresponds to a unique identifier. For example, each pixel can be numbered from bottom to top, and the pixel number can be used as the unique identifier for that pixel. Therefore, the 40 pixels are uniquely identified as 1-40. In Figure 3, the horizontal axis 1-40 represent the unique identifiers of the 40 pixels. For example, horizontal axis 1 represents the first pixel from the bottom up, and horizontal axis 2 represents the second pixel from the bottom up. Of course, other methods can also be used to label each column of pixels; this embodiment does not impose specific limitations.

[0084] In one embodiment, the wavelength selection principle of the WSS based on the LCOS chip will be explained below. In the WSS, port switching is achieved by controlling the LCOS chip. The control of the LCOS chip is implemented using the phase distribution diagrams of the LCOS chip shown in Figures 3 and 4. The phase distribution diagrams of each pixel along the y-axis of the LCOS chip form a blazed grating (the principle of the blazed grating will be explained below). Assuming the pixel size of the LCOS chip is d, and the number of pixels in one blazed grating period is N, the relationship between wavelength λ and emission angle θ is as follows: N × d × sinθ = λ. For the same wavelength λ, adjusting the number of pixels N in the blazed grating period can obtain different emission angles θ. Then, through other devices in the WSS, the wavelength of light can be selected and output.

[0085] Based on the above principle, after allocating the pixels in the shared pixel column according to the first ratio and the second ratio, it is also necessary to configure the phase of each pixel.

[0086] In this embodiment, step 103 includes at least two possible implementation methods.

[0087] The first possible implementation of step 103 is as follows: Obtain the total number of pixels in the shared pixel column, and obtain the first phase distribution map corresponding to the first channel and the second phase distribution map corresponding to the second channel; in the shared pixel column, add a unique marker to each pixel sequentially, for example, adding a unique marker to each pixel sequentially from bottom to top or from top to bottom; in the shared pixel column, sequentially take a first proportion of pixels from the total number of pixels, for example, taking a first proportion of pixels from the total number of pixels sequentially from bottom to top or from top to bottom; configure the phase of the obtained pixels using the first phase distribution map and the unique marker corresponding to each pixel; configure the phase of the remaining pixels using the second phase distribution map and the unique marker corresponding to each pixel.

[0088] Obtaining the total number of pixels in the shared pixel column is to determine the total number of pixels contained in the shared pixel column. This is the basis for subsequent phase adjustment, requiring prior knowledge of how many pixels in the shared pixel column need to be allocated and adjusted. The phase distribution map of the first channel describes the phase information of the pixels in the first channel, and the phase distribution map of the second channel describes the phase information of the pixels in the second channel. Adding a unique marker to each pixel from bottom to top means, in Figure 2, within the shared pixel column where the boundary line 212 is located, assigning a marker such as pixel 1, pixel 2, pixel N, etc., from bottom to top to each pixel (i.e., each square).

[0089] In one embodiment, as shown in Figures 2 and 3, the first channel is the region between boundary line 211 and boundary line 212, and the second channel is the region between boundary line 212 and boundary line 213. In each column of pixels between boundary line 211 and boundary line 212, each pixel, from bottom to top (i.e., along the Y-axis), corresponds to a horizontal coordinate in Figure 3. Each increment of 1 in the horizontal coordinate represents one pixel. The corresponding Y-axis has a phase. The phase configuration of pixels in each column of pixels between boundary line 211 and boundary line 212 is performed in this manner. Each column of pixels between boundary line 212 and boundary line 213 corresponds to the phase distribution diagram in Figure 4, which will not be elaborated upon in this embodiment.

[0090] In one embodiment, the specific method for configuring the phase of each pixel in the shared pixel column is as follows: the horizontal coordinate of the first phase distribution map is mapped one-to-one with the unique marker corresponding to each pixel to configure the phase of each acquired pixel; the horizontal coordinate of the second phase distribution map is mapped one-to-one with the unique marker corresponding to each pixel to configure the phase of each remaining pixel.

[0091] In one embodiment, for example, in Figure 2, the total number of pixels in a column is 40. If the first ratio is calculated to be 0.4, then the second ratio is 0.6. Starting from the bottom of the shared pixel column, along the Y-axis direction, 40 × 0.4 = 16 pixels are taken upwards sequentially. These 16 pixels belong to the first channel, and the remaining 24 pixels belong to the second channel.

[0092] The 16 pixels belonging to the first channel are phase-adjusted using the first phase distribution map of the first channel. In the first phase distribution map, the horizontal coordinate 1 corresponds to pixel 1, and the phase corresponding to the horizontal coordinate 1 is the phase of pixel 1; the horizontal coordinate 2 corresponds to pixel 2, and the phase corresponding to the horizontal coordinate 2 is the phase of pixel 2, and so on, until the phase of all 16 pixels is configured.

[0093] The remaining 24 pixels belong to the second channel. Starting with pixel 17, phase adjustment is performed from bottom to top according to the second phase distribution map of the second channel. In the second phase distribution map, the horizontal coordinate 17 corresponds to pixel 17, and the phase corresponding to the horizontal coordinate 17 is the phase of pixel 17; the horizontal coordinate 18 corresponds to pixel 18, and the phase corresponding to the horizontal coordinate 18 is the phase of pixel 18, and so on, until the phases of all 24 pixels are configured. Thus, the pixels in the shared pixel column are allocated to the two channels according to the first and second ratios.

[0094] A second possible implementation of step 103 is as follows: Obtain the total number of pixels in the shared pixel column, and obtain the first phase distribution map corresponding to the first channel and the second phase distribution map corresponding to the second channel; in the shared pixel column, add a unique marker to each pixel sequentially, for example, adding a unique marker to each pixel sequentially from bottom to top or from top to bottom; in the shared pixel column, at every preset number of pixels, sequentially take a first proportion of pixels from the total number of pixels, for example, taking a first proportion of pixels from the total number of pixels sequentially from bottom to top or from top to bottom; configure the phase of the obtained pixels using the first phase distribution map and the unique marker corresponding to each pixel; configure the phase of the remaining pixels using the second phase distribution map and the unique marker corresponding to each pixel.

[0095] The preset number of intervals can be determined based on the total number of pixels in the actual shared pixel column, and is not specifically limited in this embodiment.

[0096] Unlike the first possible method, the second possible method allocates pixels at preset intervals of a certain number of pixels.

[0097] For example, in Figure 2, the total number of pixels is 40. If the first ratio is calculated to be 0.5, then the second ratio is 0.5. Starting from the bottom of the shared pixel column along the Y-axis, every preset number of pixels (e.g., 1) are taken upwards, taking 40 × 0.5 = 20 pixels. If each unique marker in the shared pixel column from bottom to top is pixel 1, 2, 3, 4, 5, 6, 7, 8, 9, 10...40, then pixels numbered 1, 3, 5, 7, 9...39 are taken. These 20 pixels are configured according to the first phase distribution image. The phase configuration method is the same as the first achievable method mentioned above, and will not be repeated here.

[0098] The remaining pixels numbered 2, 4, 6, 8, 10...40 are adjusted in phase according to the second phase distribution image. The phase configuration method is the same as the first feasible method mentioned above, and will not be repeated here.

[0099] In summary, by labeling each pixel in the shared pixel column and then mapping this label to the horizontal coordinates of the first and second phase distribution maps, the phase of each pixel in the shared pixel column can be configured.

[0100] After configuring the pixels of the shared pixel column in accordance with step 103, the phase distribution map of the shared pixel column can be as shown in Figure 5 and Figure 6, where Figure 5 and Figure 6 show two different ratios and configurations based on different pixel number intervals.

[0101] In one embodiment, the shared pixel column may contain several hundred pixels, and the pixels are allocated according to the above configuration method. This will not be described in detail in this embodiment.

[0102] Through the two methods described above, precise control of the wavelength selection switch output frequency can be achieved on the LCOS chip, ensuring signal stability and accuracy.

[0103] In one embodiment, as shown in FIG7, the control method further includes:

[0104] Step 201: Calibrate the frequency change of the wavelength selection switch under different temperature and pressure environments using temperature and pressure sensors.

[0105] Since the frequency of WSS is generally affected by factors such as temperature and pressure, the actual change in frequency when environmental conditions change is determined by measuring the frequency of the wavelength selection switch under different temperature and pressure environments.

[0106] Step 202: Dynamically compensate the output frequency of the wavelength selection switch according to the frequency change, so as to control the output frequency of the wavelength selection switch.

[0107] In one embodiment, a model relating frequency change to temperature and pressure is developed using the measurement results from step 201. In actual frequency control, the current temperature and pressure are monitored in real time, and the compensation amount for the wavelength selection switch is calculated based on the monitored parameters. Finally, the output frequency of the wavelength selection switch is dynamically adjusted through steps 101-103 to compensate for the effects of environmental changes, ensuring stable and accurate frequency output.

[0108] This embodiment obtains the shared pixel column between adjacent first and second channels on the wavelength distribution map of the LCOS chip, calculates a first proportion of the shared pixel column occupied by the first channel, and a second proportion of the shared pixel column occupied by the second channel, and finally allocates the pixels in the shared pixel column to the first and second channels respectively according to the first and second proportions. This balances the bandwidth of the first and second channels, allowing each channel to obtain the required bandwidth while sharing pixels, thus meeting specific frequency width requirements. Secondly, while existing frequency adjustment accuracy is approximately 6.25 GHz, this solution achieves an accuracy of 0.5 GHz, enabling finer frequency adjustment and reducing noise and distortion in the signal. Furthermore, it maintains precise frequency control even when the external environment changes, significantly improving system stability.

[0109] Example 2:

[0110] In Example 1, a method for controlling the output frequency of a wavelength selective switch was proposed. In this example, a wavelength selective switch will be proposed.

[0111] The following description, in conjunction with specific structural features, will explain the internal structure of the wavelength selective switch proposed in this embodiment. In one embodiment, as shown in Figure 8, the wavelength selective switch includes: an LCOS chip 210 and at least three collimators 201, wherein the LCOS chip 210 is coupled to the at least three collimators 201; at least one of the collimators 201 is used to receive incident light including at least two wavelengths, and at least two of the collimators 201 are used to output outgoing light of different wavelengths respectively; the LCOS chip 210 is used to change the transmission direction of the incident light and obtain at least two different wavelengths of outgoing light respectively, and the phase of each pixel in the common pixel column on the LCOS chip 210 is configured according to the output frequency control method of the wavelength selective switch in the aforementioned embodiment 1.

[0112] In order to transmit a light beam in an optical fiber to the wavelength selective switch, or to transmit a light beam through the wavelength selective switch to an optical fiber, in this embodiment, the wavelength selective switch includes at least three collimators 201, which are arranged in an array. Specifically, the at least three collimators 201 include: at least one collimator 201 serving as an initial port from which incident light enters; and at least two collimators 201 serving as target ports from which outgoing light exits.

[0113] The collimator 201 is an optical element used for input and output in optical fiber communication devices. It is a device that can collimate the light beam coming out of the optical fiber, or emit the collimated light beam into the optical fiber. It has the advantage of protecting the light source from the influence of the surrounding environment. It is transformed into a parallel beam (i.e., a Gaussian beam) by a front-mounted convex lens. Its function is to couple the light beam into the wavelength selection switch with maximum efficiency.

[0114] In one specific implementation, the collimator 201 is directly contacted with the bare optical fiber and permanently fixed on the bare optical fiber, thereby improving the stability of the beam during transmission; correspondingly, the incident light includes light of at least two wavelengths, wherein the incident light enters through the at least one collimator 201 and exits through the at least two collimators 201 respectively.

[0115] It should be noted that Figure 8 shows four collimators 201. The incident light includes three wavelengths of light (λ1, λ2, λ3). As shown in Figures 8-10, the four collimators 201 are arranged in an array along the y-axis. One collimator 201 serves as the initial port, while the other three collimators 201 serve as the target ports. The incident light of the three wavelengths enters through one collimator 201 simultaneously, and after being split by the LCOS chip, three outgoing lights are obtained, which are then emitted through the other three collimators 201 respectively.

[0116] To separate light of different wavelengths in the incident light, in one embodiment, as shown in FIG9, the wavelength selection switch further includes a grating 205, which is located between the at least three collimators 201 and the LCOS chip 210, and is coupled to the at least three collimators 201 and the LCOS chip 210 respectively; the grating 205 is used to diffract and split the incident light to form corresponding light spots, and the light spots cover different areas on the surface of the LCOS chip 210 respectively.

[0117] The grating 205 is an optical device that produces diffraction by being composed of a large number of parallel slits of equal width and spacing. It has thousands or even tens of thousands of grooves engraved within a 1cm width. The light beam passing through the grating 205 will form a light spot. The periodic structure on the grating separates light of different wavelengths. It is classified into a transmission grating and a reflection grating according to whether the light beam is transmitted or reflected in the grating.

[0118] In this embodiment, the grating 205 used is mainly a reflection grating. Furthermore, the grating 205 is etched into a sawtooth-shaped groove cross-section, so that the light energy of the grating is concentrated in a predetermined direction, so that the light energy is transferred from the zero-order light spot to a certain order light spot. When detected from this predetermined direction, the intensity of the spectrum is the greatest, which constitutes a blazed grating.

[0119] As shown in Figure 10, three different wavelengths of light (λ1, λ2, λ3) are formed by the grating 205, each forming a light spot corresponding to its wavelength. These light spots are projected onto different areas of the LCOS chip surface (λ1, λ2, λ3 as shown in Figure 2). The surface of the LCOS chip is composed of a uniformly distributed pixel matrix, where each cell represents a pixel. The three different wavelengths of light (λ1, λ2, λ3) cover multiple pixels along the y-axis. The combinations of these pixels are projected onto the surface of the LCOS chip, forming corresponding blazed gratings. To form the desired blazed grating, the phase of each pixel is adjustable within a period of 0 to 2π. The phase of the multiple pixels is determined according to the phase distribution map, thereby forming the desired blazed grating.

[0120] To convert the light beams of different wavelengths into two beams and allow them to propagate along different optical paths to form a larger light spot, while facilitating subsequent adjustment of the optical paths of the light beams of different wavelengths, in one embodiment, as shown in FIG10, the wavelength selection switch further includes a polarizer 202. The polarizer 202 is located between the at least three collimators 201 and the grating 205, and is coupled to the at least three collimators 201 and the grating 205 respectively. The polarizer 202 is used to split the incident light passing through at least one of the collimators 201 into two mutually perpendicular linearly polarized beams and input them into the grating 205 respectively. The polarizer 202 is also used to combine the outgoing light passing through the grating 205 into one beam and output it to at least two of the collimators 201 respectively.

[0121] The polarizer 202 is a device that converts unpolarized light into polarized light. There are linear polarizers and circular polarizers. The function of a circular polarizer is to convert the input light signal into circularly polarized light output, while the function of a linear polarizer is to convert the input light signal into linearly polarized light output. According to the different implementation principles of linear polarizers, they can be further divided into absorption-type linear polarizers and beam-splitting linear polarizers. Beam-splitting linear polarizers use birefringent crystals, such as Nikkor prisms or Wollaston prisms, to split the input light signal into two beams, with at least one beam being linearly polarized and the other being linearly polarized or partially polarized. Absorption-type linear polarizers use polarizers to absorb polarized light that is not aligned with the transmission axis of the polarizer, while transmitting polarized light that is aligned with the transmission axis of the polarizer.

[0122] In this embodiment, the polarizer 202 is preferably a beam-splitting linear polarizer. By applying the polarizer 202, the beams of different wavelengths are converted into two beams, and the beams of different wavelengths are transmitted on different optical paths.

[0123] In one embodiment, as shown in FIG10, the wavelength selection switch further includes a first lateral beam-expanding cylindrical lens 203, a second lateral beam-expanding cylindrical lens 204, a longitudinal switching cylindrical lens 206, and a lateral focusing cylindrical lens 207. The first lateral beam-expanding cylindrical lens 203 is coupled to the second lateral beam-expanding cylindrical lens 204, and the longitudinal switching cylindrical lens 206 is coupled to the lateral focusing cylindrical lens 207. The first lateral beam-expanding cylindrical lens 203 and the second lateral beam-expanding cylindrical lens 204 are sequentially disposed in the optical path of the incident light and located at the... Between the polarizer 202 and the grating 205, the first lateral beam-expanding cylindrical lens 203 and the second lateral beam-expanding cylindrical lens 204 are coupled to the polarizer 202 and the grating 205, respectively; the longitudinal switching cylindrical lens 206 and the lateral focusing cylindrical lens 207 are sequentially disposed in the optical path of the emitted light and located between the grating 205 and the LCOS chip 210, and the longitudinal switching cylindrical lens 206 and the lateral focusing cylindrical lens 207 are coupled to the grating 205 and the LCOS chip 210, respectively.

[0124] The following description, using a specific beam transmission line, explains the implementation principle of the wavelength selection switch in this embodiment. Along the y-axis, as shown in Figure 10, after the incident light (λ1, λ2, λ3) is collimated by the collimator 201, it is split into two mutually perpendicular linearly polarized beams (0° linearly polarized light along the x-direction and 90° linearly polarized light along the y-direction) by the polarizer 202. The 90° linearly polarized light in the y-direction, after passing through a 45° half-wave plate, rotates its polarization state by 90°, becoming 0° linearly polarized light along the x-direction. The two mutually perpendicular linearly polarized beams become parallel linearly polarized beams, meaning their polarization states are consistent. After passing through the longitudinal switching lens 206, the incident light (λ1, λ2, λ3) is focused onto the LCOS chip 210. Along the y-axis, the incident light (λ1, λ2, λ3) is not separated and shares different optical paths. The incident light (λ1, λ2, λ3) is reflected by the LCOS chip 210 after passing through it, changing its polarity. The incident light (λ1, λ2, λ3) is converted into the outgoing light (λ1, λ2, λ3), and the optical path of the outgoing light (λ1, λ2, λ3) is opposite to that of the incident light (λ1, λ2, λ3) in the y-axis direction.

[0125] Specifically, along the x-axis, as shown in Figure 10, after the incident light (λ1, λ2, λ3) is collimated by the collimator 201, it is expanded by the first lateral beam-expanding cylindrical lens 203 and the second lateral beam-expanding cylindrical lens 204, respectively. After diffraction and dispersion by the grating 205, the beams of different wavelengths are separated from each other. The lateral focusing cylindrical lens 207 then focuses the beams of different wavelengths onto different regions of the LCOS chip 210, as shown in Figure 2. Based on their different wavelengths, the beams of different wavelengths correspond to different regions on the surface of the LCOS chip 210. Along the x-axis, the incident light (λ1, λ2, λ3) is separated from each other. The incident light (λ1, λ2, λ3) is reflected by the LCOS chip 210 after passing through it, changing its polarity. The incident light (λ1, λ2, λ3) is converted into the outgoing light (λ1, λ2, λ3), and the optical path of the outgoing light (λ1, λ2, λ3) is opposite to that of the incident light (λ1, λ2, λ3) in the x-axis direction.

[0126] The specific process of the control method for the output frequency of the wavelength selection switch is described in Example 1, and will not be explained in detail in this example.

[0127] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for controlling the output frequency of a wavelength selective switch, characterized in that, The control method is used to control the output frequency of a wavelength selective switch based on an LCOS chip, including: Obtain the shared pixel column between adjacent first and second channels on the wavelength distribution map of the LCOS chip; Obtain a first proportion of the first channel occupying the shared pixel column, and a second proportion of the second channel occupying the shared pixel column; The pixels in the shared pixel column are assigned to the first channel and the second channel respectively according to the first ratio and the second ratio, and the phase of each pixel in the shared pixel column is configured according to the channel to which the pixel belongs.

2. The method for controlling the output frequency of a wavelength selective switch according to claim 1, characterized in that, The step of obtaining the shared pixel column between adjacent first and second channels on the wavelength distribution map of the LCOS chip includes: The frequency ranges of the first channel and the second channel are preset respectively, and the common frequency at the common point of the two channels is obtained according to the corresponding frequency range; The pixel column in which the shared frequency is located is obtained according to the pre-stored frequency table, and the obtained pixel column is the shared pixel column.

3. The method for controlling the output frequency of a wavelength selective switch according to claim 2, characterized in that, The step of obtaining the first proportion of the first channel occupying the shared pixel column and the second proportion of the second channel occupying the shared pixel column includes: The first frequency of the pixel column adjacent to the shared pixel column in the first channel is obtained according to the pre-stored frequency table; The second frequency of the pixel column adjacent to the shared pixel column in the second channel is obtained according to the pre-stored frequency table; The first ratio and the second ratio are calculated based on the shared frequency, the first frequency, and the second frequency.

4. The method for controlling the output frequency of a wavelength selective switch according to claim 3, characterized in that, The first ratio is calculated as follows: The second ratio is calculated as follows: λ2=1-λ1 Wherein, λ1 is the first ratio, λ2 is the second ratio, f is the shared frequency, f(j) is the first frequency, and f(j+1) is the second frequency.

5. The method for controlling the output frequency of a wavelength selective switch according to claim 1, characterized in that, The step of allocating pixels in the shared pixel column to the first channel and the second channel respectively according to the first ratio and the second ratio, and configuring the phase of each pixel in the shared pixel column according to the channel to which the pixel belongs includes: Obtain the total number of pixels in the shared pixel column, and obtain the first phase distribution map corresponding to the first channel and the second phase distribution map corresponding to the second channel; In the shared pixel column, a unique marker is added to each pixel in turn; In the shared pixel column, a first proportion of pixels from the total number of pixels are taken in sequence, and the phase of the obtained pixels is configured by the first phase distribution map and the unique tag corresponding to each pixel; The phase of the remaining pixels is configured using the second phase distribution map and the unique marker corresponding to each pixel.

6. The method for controlling the output frequency of a wavelength selective switch according to claim 1, characterized in that, The step of allocating pixels in the shared pixel column to the first channel and the second channel respectively according to the first ratio and the second ratio, and configuring the phase of each pixel in the shared pixel column according to the channel to which the pixel belongs, further includes: Obtain the total number of pixels in the shared pixel column, and obtain the first phase distribution map corresponding to the first channel and the second phase distribution map corresponding to the second channel; In the shared pixel column, a unique marker is added to each pixel in turn; In the shared pixel column, at every preset number of pixels, a first proportion of pixels from the total number of pixels are taken sequentially, and the phase of the obtained pixels is configured using the first phase distribution map and the unique marker corresponding to each pixel; The phase of the remaining pixels is configured using the second phase distribution map and the unique marker corresponding to each pixel.

7. The method for controlling the output frequency of a wavelength selective switch according to claim 5 or 6, characterized in that, The step of configuring the phase of the acquired pixels using the first phase distribution map and the unique marker corresponding to each pixel includes: The horizontal coordinates of the first phase distribution map are mapped one-to-one with the unique marker corresponding to each pixel in order to configure the phase of each acquired pixel. The step of configuring the phase of the remaining pixels using the second phase distribution map and the unique marker corresponding to each pixel includes: The horizontal coordinates of the second phase distribution map are mapped one-to-one with the unique marker corresponding to each pixel in order to configure the phase of each remaining pixel.

8. The method for controlling the output frequency of a wavelength selective switch according to claim 1, characterized in that, The control method further includes: The frequency variation of the wavelength selection switch under different temperature and pressure environments was calibrated using temperature and pressure sensors. The output frequency of the wavelength selection switch is dynamically compensated based on the frequency change to control the output frequency of the wavelength selection switch.

9. The method for controlling the output frequency of a wavelength selective switch according to claim 5 or 6, characterized in that, The phase distribution map of each channel is the phase distribution map of the non-shared pixel column, and the phase distribution map reflects the phase of each pixel in the column; Among them, non-shared pixel columns refer to pixel columns that belong only to the first or second channel and are not shared by other channels. The phase distribution map of each non-shared pixel column in each channel is the same.

10. The method for controlling the output frequency of a wavelength selective switch according to claim 5 or 6, characterized in that, The horizontal axis of the phase distribution map represents the marker of each pixel along the Y-axis of the corresponding channel in the wavelength distribution map; the vertical axis represents the phase value of each pixel, i.e., the phase ranges from 0 to 2π.

11. The method for controlling the output frequency of a wavelength selective switch according to claim 1, characterized in that, The pixel size of the LCOS chip is d, and the number of pixels in one blazed grating cycle is N. The relationship between the wavelength λ and the emission angle θ is as follows: N×d×sinθ=λ; For the same wavelength λ, different emission angles θ can be obtained by adjusting the number N of pixels in the blazed grating period.

12. A wavelength selective switch, characterized in that, include: An LCOS chip (210) and at least three collimators (201), wherein the LCOS chip (210) is coupled to the at least three collimators (201); At least one of the collimators (201) is used to receive incident light including at least two wavelengths, and at least two of the collimators (201) are used to output outgoing light of different wavelengths respectively; The LCOS chip (210) is used to change the transmission direction of the incident light and obtain at least two different wavelengths of the outgoing light. The phase of each pixel in the common pixel column on the LCOS chip (210) is configured according to the control method of the output frequency of the wavelength selection switch as described in any one of claims 1-11.

13. The wavelength selective switch according to claim 12, characterized in that, The collimator (201) is directly contacted with the bare optical fiber and fixed on the bare optical fiber; The incident light enters through the at least one collimator (201) and exits through the at least two collimators (201) respectively.

14. The wavelength selective switch according to claim 12, characterized in that, The wavelength selection switch further includes a grating (205), which is located between the at least three collimators (201) and the LCOS chip (210), and is coupled to the at least three collimators (201) and the LCOS chip (210) respectively; the grating (205) is used to diffract and split the incident light to form corresponding light spots, and the light spots cover different areas on the surface of the LCOS chip (210) respectively.

15. The wavelength selective switch according to claim 14, characterized in that, The wavelength selection switch further includes a polarizer (202), which is located between the at least three collimators (201) and the grating (205), and is coupled to the at least three collimators (201) and the grating (205) respectively. The polarizer (202) is used to split the incident light passing through at least one of the collimators (201) into two mutually perpendicular linearly polarized lights and input them into the grating (205) respectively. The polarizer (202) is also used to combine the outgoing light passing through the grating (205) into one light and output it into at least two of the collimators (201).

16. The wavelength selective switch according to claim 15, characterized in that, The wavelength selection switch further includes a first lateral beam-expanding cylindrical lens (203), a second lateral beam-expanding cylindrical lens (204), a longitudinal switching cylindrical lens (206), and a lateral focusing cylindrical lens (207). The first lateral beam-expanding cylindrical lens (203) is coupled to the second lateral beam-expanding cylindrical lens (204), and the longitudinal switching cylindrical lens (206) is coupled to the lateral focusing cylindrical lens (207). The first transverse beam-expanding cylindrical lens (203) and the second transverse beam-expanding cylindrical lens (204) are sequentially disposed in the optical path of the incident light and located between the polarizer (202) and the grating (205). The first transverse beam-expanding cylindrical lens (203) and the second transverse beam-expanding cylindrical lens (204) are coupled to the polarizer (202) and the grating (205) respectively. The longitudinal switching cylindrical lens (206) and the transverse focusing cylindrical lens (207) are sequentially disposed in the optical path of the emitted light and located between the grating (205) and the LCOS chip (210). The longitudinal switching cylindrical lens (206) and the transverse focusing cylindrical lens (207) are coupled to the grating (205) and the LCOS chip (210) respectively.

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