A channel switching device

Abstract

This invention provides a channel switching device, comprising an AWG array, a grating, and an optical deflector array. The channel switching device transmits an incident WDM signal to the optical deflector array via the AWG array and the grating. The AWG array disperses the WDM signal along the y-direction, and the grating disperses the WDM signal along the x-direction, which is perpendicular to the x-direction. The optical deflector array deflects the dispersed WDM signal at different angles along the x-direction. The AWG array and the grating also combine the deflected WDM signal and output the combined WDM signal. This invention can improve the spectral bandwidth of the switchable optical signal and increase the channel density in the spectrum.

Description

Technical Field

[0001] This invention relates to the field of optical communication technology, and in particular to a channel switching device. Background Technology

[0002] The minimum channel spacing and spectral range that a wavelength selective switch (WSS) can perform optical switching largely depend on the dispersion method used. Currently, most dispersion units in wavelength selective switches use gratings for dispersion because the spectral range of gratings can completely cover the communication band. The dispersion capability of a grating is related to its grating density. Due to limitations in grating manufacturing processes and materials, the grating grating density that can support near-infrared dispersion is mostly less than 1800 lines / mm. Therefore, gratings can only support a minimum channel spacing of 50 GHz. Furthermore, using multiple gratings for multiple dispersions places extremely high demands on the uniformity of grating manufacturing. After the beam passes through the grating multiple times, it is difficult to obtain an ideal spot shape, which makes further processing by the optical switching engine impossible. Therefore, achieving dense channel dispersion below 50 GHz using gratings is very difficult. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a channel switching device that, by setting up an AWG array and a grating, can increase the spectral width of the switchable optical signal and increase the channel density in the spectrum.

[0004] This invention provides a channel switching device, which includes: an AWG array, a grating, and an optical deflector array;

[0005] The channel switching device transmits the incident WDM signal to the optical deflector array through an AWG array and a grating. The AWG array is used to disperse the WDM signal along the y-direction, and the grating is used to disperse the WDM signal along the x-direction. The y-direction is perpendicular to the x-direction.

[0006] An optical deflector array is used to deflect the dispersed WDM signal at different angles in the x-direction;

[0007] The AWG array and grating are also used to combine the deflected WDM signals and output the combined WDM signals.

[0008] Optionally, the channel switching device further includes: a lens group;

[0009] The demultiplexing / multiplexing ports, lens groups, and optical deflector array on the AWG array are arranged sequentially along the z-direction. The lens group includes multiple lenses arranged along the z-direction, and the grating is located between the multiple lenses. The z-direction is perpendicular to the y-direction and the x-direction, respectively.

[0010] The lens group is used to convert the angular offset of the deflected WDM signal in the x-direction into a position offset along the x-direction, so that the grating and AWG array can combine the offset WDM signal.

[0011] Optionally, the lens group includes: cylindrical lenses and spherical lenses;

[0012] The cylindrical lens, grating, and spherical lens are arranged sequentially along the z-direction. The cylindrical lens and the spherical lens have the same focal length. The grating is located on the rear focal plane of the cylindrical lens and on the front focal plane of the spherical lens. The distance between the spherical lens and the optical deflector array is the focal length of the cylindrical lens.

[0013] A spherical lens is used to convert the angular offset of the deflected WDM signal in the x-direction into a position offset along the x-direction.

[0014] Optionally, the channel switching device further includes: a collimating lens array;

[0015] The plane containing the collimating lens array is perpendicular to the z-direction and is located between the splitting / combining port and the lens group in the z-direction.

[0016] Optionally, the plane where the wave splitting / combining port is located is parallel to the plane where the collimating lens array is located, the wave splitting / combining port corresponds one-to-one with the collimating lens in the collimating lens array, the plane where the wave splitting / combining port is located is parallel to the plane where the collimating lens is located, and the distance between the plane where the wave splitting / combining port is located and the plane where the collimating lens is located is the focal length of the collimating lens.

[0017] Optionally, the AWG array includes multiple AWGs arranged along the x-direction.

[0018] Optionally, each AWG includes an input / output port at one end and multiple demultiplexing / multiplexing ports at the other end, with the multiple demultiplexing / multiplexing ports on each AWG arranged along the y-direction.

[0019] Optionally, the optical deflector array includes: a microelectromechanical system micromirror array.

[0020] Optionally, the grating is a one-dimensional grating.

[0021] The channel switching device provided in this invention improves the spectral width of the switchable optical signal and increases the channel density in the spectrum by setting an AWG array and a grating, realizing all-optical switching of wide-spectrum ultra-dense channels and improving the efficiency of optical communication. At the same time, this channel switching device utilizes MEMS micromirror deflection to ensure low insertion loss and switching speed, meeting the requirements of cascading multiple channel switching devices and fast switching in complex optical networks. Thus, this channel switching device can be applied to multi-channel optical switching of large nodes in optical networks and supports ultra-dense channel spacing, resulting in a lower probability of network request blocking compared to optical networks with large channel spacing. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic structural diagram of a channel switching device according to an embodiment of the present application, wherein (a) is a schematic structural diagram in the yz plane and (b) is a schematic structural diagram in the xz plane;

[0024] Figure 2 This is a schematic diagram of the arrangement of an AWG array according to an embodiment of this application;

[0025] Figure 3 This is a schematic diagram of the light spot distribution on a micromirror array of a microelectromechanical system according to an embodiment of this application.

[0026] Figure label:

[0027] 1. AWG array; 2. Grating; 3. Optical deflector array; 4. Lens group; 41. Cylindrical lens; 42. Spherical lens; 5. Collimating lens array. Detailed Implementation

[0028] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0030] Spatial relation terms such as "below," "under," "below," "below," "above," and "above" are used here to describe the relationship between one element or feature shown in the figure and other elements or features. Similarly, "directly above" can be used here to describe an element or feature shown in the figure that coincides in a vertical straight line direction, which may be partial or complete, depending on the actual situation or the content of the illustration. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, the element or feature described as "below," "below," or "below" of other elements will be oriented "above" other elements or features. Therefore, the exemplary terms "below" and "below" can include both upper and lower orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein will be interpreted accordingly.

[0031] It should be noted that when an element is referred to as "fixedly connected" to another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intervening element. Conversely, when an element is referred to as being "directly on" another element, there is no intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0032] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.

[0033] The digital transformation of various industries and the increasing number of mobile smart devices have placed high demands on communication capacity. Wavelength Division Multiplexing (WDM), as a mature technology, supports the simultaneous transmission of multiple wavelengths through channels and has become one of the main means of expanding optical communication networks. However, with the increasing number of channels in optical transmission networks, channel management has become an important issue. Reconfigurable Optical Add / Drop Multiplexer (ROADM) technology can be remotely operated via software to control the uploading or downloading of any number of wavelength combinations in optical network nodes, flexibly allocating different wavelengths. Compared with fixed switching methods, this reduces the risk of communication congestion and greatly improves communication efficiency.

[0034] Wavelength selective switches (WSS), as an all-optical switching component in the ROADM architecture, can switch any wavelength channel in the WDM signal at the input port to any output port, playing a crucial role in numerous current and future information exchange scenarios. Currently, the switching technologies for WSS are mainly spatial light modulators (SLMs) or micro-electro-mechanical systems (MEMS). MEMS technology primarily uses MEMS micromirrors to deflect the light beam, thereby achieving optical switching. Compared to SLMs, MEMS micromirrors offer advantages such as faster response speed and lower insertion loss.

[0035] However, with the rapid growth in communication demand, the C-band spectrum utilization rate with a minimum channel spacing of 50 GHz is approaching its limit. More and more C+L band optical network-related devices are being developed and commercialized, and the ability to support wideband optical signal processing has become the future development direction of optical communication devices.

[0036] Dense channel technology, compared to spread spectrum, is another means of increasing the number of communication channels. Besides offering greater flexibility and spectrum utilization in meeting user demands for different communication rates, dense channel technology can also effectively reduce the probability of optical network request congestion. Against this backdrop, a wideband dense channel solution (WSS) needs to be proposed.

[0037] Furthermore, compared to gratings, arrayed waveguide gratings (AWGs) can achieve ultra-dense wavelength division multiplexing (WDM) with channel spacing below 50 GHz, and their transmission spectrum passband varies periodically with the free-space spectral range (FSR). However, designing a large number of channels for narrow-channel-spacing AWGs is very difficult, making it hard to match the spectral width of the communication band. In terms of dispersion, achieving a wide spectral range requires a wide channel spacing, while achieving a narrow channel spacing requires a narrow spectral range. Therefore, WSS designs cannot simultaneously meet the requirements of ultra-dense wavelength division multiplexing and a wide spectrum.

[0038] One embodiment of the present invention provides a channel switching device, specifically a wavelength selective switch based on a MEMS micromirror array, see [link to relevant documentation]. Figure 1 The wavelength selection switch includes: AWG array 1, grating 2 and optical deflector array 3.

[0039] A wavelength selective switch transmits the incident WDM signal to an optical deflector array 3 via an AWG array 1 and a grating 2. The AWG array 1 disperses the WDM signal along the y-direction, and the grating 2 disperses the WDM signal along the x-direction, which is perpendicular to the x-direction. The optical deflector array 3 includes a MEMS micromirror array or a liquid crystal on silicon (LCoS) cell array, etc. In this embodiment, the optical deflector array 3 is a MEMS micromirror array.

[0040] Optical deflector array 3 is used to deflect the dispersed WDM signal at different angles in the x-direction. AWG array 1 and grating 2 are also used to combine the deflected WDM signal and output the combined WDM signal.

[0041] The channel switching device provided in this embodiment of the invention, by setting up an AWG array 1 and a grating 2, increases the spectral width of the switchable optical signal and increases the channel density in the spectrum, realizing all-optical switching of wide-spectrum ultra-dense channels and improving the efficiency of optical communication. Furthermore, the channel switching device provided in this embodiment utilizes an optical deflector array 3 to reflect the dispersed WDM signal back to the AWG array 1 and grating 2 for multiplexing, which not only improves the space utilization of the channel switching device but also ensures low insertion loss and switching speed. This meets the requirements of cascading multiple channel switching devices and rapid switching in complex optical networks, making the channel switching device particularly suitable for multi-channel optical switching of large nodes in optical networks and supporting ultra-dense channel spacing, resulting in a lower network request blocking probability compared to optical networks with large channel spacing.

[0042] Furthermore, the channel switching device also includes: lens group 4.

[0043] The demultiplexing / multiplexing ports on the AWG array 1 are arranged sequentially with the lens group 4 and the optical deflector array 3 along the z-direction. The lens group 4 includes multiple lenses arranged along the z-direction, and the grating 2 is located between the multiple lenses. The z-direction is perpendicular to the y-direction and the x-direction, respectively.

[0044] Lens group 4 is used to convert the angular offset of the deflected WDM signal in the x-direction into a position offset along the x-direction, so that grating 2 and AWG array 1 can combine the offset WDM signal.

[0045] In this embodiment, the lens group 4 includes a cylindrical lens 41 and a spherical lens 42. The cylindrical lens 41, the grating 2, and the spherical lens 42 are arranged sequentially along the z-direction. The cylindrical lens 41 and the spherical lens 42 have the same focal length. The grating 2 is located on the rear focal plane of the cylindrical lens 41 and on the front focal plane of the spherical lens 42. The distance between the spherical lens 42 and the optical deflector array 3 is the focal length of the cylindrical lens 41. The spherical lens 42 is used to convert the angular shift of the deflected WDM signal in the x-direction into a positional shift along the x-direction.

[0046] Furthermore, the channel switching device also includes a collimating lens array 5.

[0047] The collimating lens array 5 is located in a plane perpendicular to the z-direction and between the demultiplexing / multiplexing port and the lens group 4 in the z-direction. The collimating lens array 5 and the lens group 4 are used to transmit the dispersed WDM signal to the optical deflector array 3, so that the optical deflector array 3 reflects the dispersed WDM signal. The reflected WDM signal is then transmitted to the output of the channel switching device through the lens group 4 and the collimating lens array 5.

[0048] It should be noted that the focal length of the collimating lens in the collimating lens array 5 is not exactly the same in different orientations. This embodiment does not make specific limitations on this or the distance between the collimating lens and the cylindrical lens.

[0049] The plane containing the wave splitter / combiner port is parallel to the plane containing the collimating lens array 5. The wave splitter / combiner port corresponds one-to-one with the collimating lens in the collimating lens array 5. The distance between the plane containing the wave splitter / combiner port and the plane containing the collimating lens is the focal length of the collimating lens.

[0050] Understandably, in combination Figure 2 The AWG array 1 includes multiple AWGs. These AWGs can be arranged along the x-direction or the y-direction. In this embodiment, the multiple AWGs can be arranged along the x-direction, and the grating 2 is a one-dimensional grating 2 used to disperse the WDM signal to be incident on the MEMS micromirror array along the x-direction.

[0051] Each AWG has an input / output port at one end and multiple demultiplexing / multiplexing ports at the other end. The multiple demultiplexing / multiplexing ports on each AWG are arranged along the y-direction.

[0052] The working principle of the channel switching device provided in this embodiment is as follows: the light of each port of the AWG, namely the wavelength division / multiplexing port and the input / output port, is transmitted in the form of optical fiber; the input / output port of the AWG serves as the input / output port of the WSS, and the wavelength division / multiplexing port of the AWG is arranged in a rectangular array.

[0053] Combination Figure 1 The WDM signal input to the channel switching device is dispersed by an AWG (Automatic Wavelength Gear) and then decomposed into m narrow-channel WDM signals arranged along the y-direction at the m demultiplexing / multiplexing ports of the AWG. Each demultiplexing / multiplexing port contains n wavelength channels with mutually spaced FSR (Frequency Sequencer) spectral widths. This invention does not limit the specific values ​​of m and n; in this embodiment, both m and n are 3. Subsequently, each beam of light, i.e., the WDM signal, is collimated by the collimating lens array 5. When the light enters the lens group 4, in the yz plane, a 1:1 4f system composed of a cylindrical lens 41 with a focal length of f and a spherical lens 42 with a focal length of f controls the size of the light spot on the MEMS micromirror array in the y-direction. In the xz plane, the light is decomposed by the grating 2 into n wavelength channels dispersed along the x-direction, combined with... Figure 3 , where λ m1 , λ m2 ..., λ mn This refers to the dispersion of light along one of the optical paths by grating 2, i.e., the result of grating 2 dispersing light along one of the optical paths; λ 11 , λ 21 ..., λ m1 This refers to the dispersion of light along one optical path by an AWG (Automatic Light Array), specifically the dispersion of light along that path by an AWG. On the MEMS micromirror array plane, by controlling the angle of the micromirrors, light of different wavelengths is deflected at different angles in the x-direction, while the light remains undeflected in the y-direction, thus returning along its original path. The reflected light passes through a 2f system composed of spherical lenses 42 with a focal length f in the x-direction, converting the different angular offsets into positional offsets along the x-direction, i.e., transforming different angular offsets into different off-axis displacements along the x-direction. After being combined by grating 2, the light is further combined by the input / output ports of at least one other AWG, thus switching the different wavelength light signals to input / output ports other than the AWG receiving the initial WDM signal.

[0054] The channel switching device provided in this embodiment is based on the characteristics of MEMS micromirror arrays, which have fast deflection speed and low insertion loss. This channel switching device can be applied to high-capacity dense wavelength division multiplexing communication scenarios with large nodes in optical networks, and plays an important role in applications that require fast response and cascading.

[0055] In the description of this specification, the references to terms such as "some embodiments," "other embodiments," "ideal embodiments," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example that are included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0056] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0057] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A channel switching device, characterized in that, The channel switching device includes: an AWG array, a grating, and an optical deflector array; The channel switching device transmits the incident WDM signal to the optical deflector array through the AWG array and the grating, wherein the AWG array is used to disperse the WDM signal along the y-direction, and the grating is used to disperse the WDM signal along the x-direction, wherein the y-direction is perpendicular to the x-direction; The optical deflector array is used to deflect the dispersed WDM signal at different angles in the x direction; The AWG array and the grating are also used to combine the deflected WDM signal and output the combined WDM signal. The channel switching device further includes: a lens group; The wave splitting / combining ports on the AWG array are arranged sequentially with the lens group and the optical deflector array along the z-direction. The lens group includes multiple lenses arranged along the z-direction, and the grating is located between the multiple lenses. The z-direction is perpendicular to the y-direction and the x-direction, respectively. The lens group is used to convert the angular offset of the deflected WDM signal in the x-direction into a position offset along the x-direction, so that the grating and the AWG array can combine the offset WDM signal.

2. The channel switching device according to claim 1, characterized in that, The lens group includes: cylindrical lenses and spherical lenses; The cylindrical lens, the grating, and the spherical lens are arranged sequentially along the z-direction. The cylindrical lens and the spherical lens have the same focal length. The grating is located on the rear focal plane of the cylindrical lens and on the front focal plane of the spherical lens. The distance between the spherical lens and the optical deflector array is the focal length of the cylindrical lens. The spherical lens is used to convert the angular offset of the deflected WDM signal in the x-direction into a position offset along the x-direction.

3. The channel switching device according to claim 2, characterized in that, The channel switching device further includes: a collimating lens array; The plane containing the collimating lens array is perpendicular to the z-direction and is located between the wave splitting / combining port and the lens group in the z-direction.

4. The channel switching device according to claim 3, characterized in that, The plane containing the wave splitter / combiner is parallel to the plane containing the collimating lens array. Each wave splitter / combiner corresponds to a collimating lens in the collimating lens array. The distance between the plane containing the wave splitter / combiner and the plane containing the collimating lens is the focal length of the collimating lens.

5. The channel switching device according to claim 1, characterized in that, The AWG array includes multiple AWGs, which are arranged along the x-direction.

6. The channel switching device according to claim 5, characterized in that, Each AWG has an input / output port at one end and multiple demultiplexing / multiplexing ports at the other end, with the multiple demultiplexing / multiplexing ports on each AWG arranged along the y-direction.

7. The channel switching apparatus according to any one of claims 1 to 6, characterized in that, The optical deflector array includes: a microelectromechanical system micromirror array.

8. The channel switching apparatus according to any one of claims 1 to 6, characterized in that, The grating is a one-dimensional grating.

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