Optical switch with reduced size fiber array and low mirror tilt angle

Abstract

The invention relates to an optical switch with a reduced-sized fiber array and a low mirror tilt angle. The optical switch may include a first array of optical ports, a first array of beam forming elements, and a first array of beam steering elements. The optical switch may also include a first set of optical elements for causing an area of a projected beam array field at a plane of the first array of beam-forming elements to be greater than an area of the first array of beam-forming elements. The first set of optical elements may be located in an optical coupling region between the first array of beam forming elements and the first array of beam steering elements. The optical switch may include a second array of beam steering elements, a second array of beam forming elements, and a second array of optical ports.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority to U.S. Provisional Patent Application No. 63 / 595,103, filed on November 1, 2023, entitled “OPTICAL SWITCH WITH REDUCED SIZE FIBER ARRAY AND LOW MIRROR TILT ANGLE”. The disclosure of that prior application is considered a part of this patent application and is incorporated by reference into this patent application. Technical Field

[0003] The present disclosure generally relates to an optical switch and an optical switch having a reduced fiber array size and a low mirror tilt angle. Background Art

[0004] In optical communication networks, optical signals having multiple optical channels at individual wavelengths (often referred to as "wavelength channels") are typically transmitted from one location to another over a length of optical fiber. An optical cross-connector is a type of optical switch that allows optical signals to be switched from one optical fiber to another. Summary of the invention

[0005] In some implementations, an optical switch includes a first optical port array; a first beam forming element array, wherein the first optical port array is optically coupled to the first beam forming element array; a first beam steering element array, wherein the first beam forming element array is optically coupled to the first beam steering element array; a first group of optical elements for making the area of ​​the projection beam array field at the plane of the first beam forming element array larger than the area of ​​the first beam forming element array, wherein the first group of optical elements is located in an optical coupling region between the first beam forming element array and the first beam steering element array; a second beam steering element array, wherein the first beam steering element array is optically coupled to the second beam steering element array; a second beam forming element array, wherein the second beam steering element array is optically coupled to the second beam forming element array; and a second optical port array, wherein the second beam forming element array is optically coupled to the second optical port array.

[0006] In some implementations, an area of ​​the beam array field at the plane of the first array of beam steering elements is larger than an area corresponding to beam forming elements in the first array of beam forming elements.

[0007] In some implementations, the first set of optical elements provides a beam spacing that matches a pitch between adjacent beam steering elements in the first array of beam steering elements.

[0008] In some implementations, the optical switch also includes a second set of optical elements, which are used to make the area of ​​the projection beam array field at the plane of the second beam forming element array larger than the area of ​​the second beam forming element array, wherein the second set of optical elements is located in the optical coupling region between the second beam steering element array and the second beam forming element array.

[0009] In some implementations, an area of ​​the beam array field at the plane of the second array of beam steering elements is larger than an area corresponding to beam forming elements in the second array of beam forming elements.

[0010] In some implementations, the second set of optical elements provides a beam spacing that matches a pitch between adjacent beam shaping elements in the second array of beam shaping elements.

[0011] In some implementations, the beam steering requirement associated with the first beam steering element array is approximately equal to half the size of the second beam steering element array divided by the distance between the first beam steering element array and the second beam steering element array.

[0012] In some implementations, in the rest position, each beam steering element in the first array of beam steering elements is used to direct a corresponding light beam to approximately the same position on the second array of beam steering elements.

[0013] In some implementations, a beam waist of a given optical beam propagating in the optical switch is located approximately midway between the first array of beam steering elements and the second array of beam steering elements.

[0014] In some implementations, dimensions of the first array of beam shaping elements are smaller than corresponding dimensions of the first array of beam steering elements.

[0015] In some implementations, the optical switch further includes an aperture element located in an optical coupling region between the second array of beam steering elements and the second array of beam forming elements.

[0016] In some implementations, the optical switch also includes a Fourier lens positioned in an optical coupling region between a first beam steering element array and a second beam steering element array, wherein a beam steering requirement associated with the first beam steering element array is approximately equal to half the size of the second beam steering element array divided by a focal length of the Fourier lens.

[0017] In some implementations, a beam waist of a given optical beam propagating in the optical switch is located approximately at the first array of beam steering elements and approximately at the second array of beam steering elements.

[0018] In some implementations, the first array of beam steering elements and the second array of beam steering elements each include a plurality of independent beam steering elements for independently directing light beams.

[0019] In some implementations, at least one of the first beam steering element array or the second beam steering element array is a reflective beam steering element array.

[0020] In some implementations, at least one optical element of the first set of optical elements located in the optical coupling region between the first array of beam shaping elements and the first array of beam steering elements is a reflective optical element.

[0021] In some implementations, an optical switch includes a first group of optical elements for making an area of ​​a projection beam array field at a plane of a first beam forming element array of an optical device larger than an area of ​​the first beam forming element array, wherein the first group of optical elements is located in an optical coupling region between the first beam forming element array and a first beam steering element array of the optical device; and a second group of optical elements for making an area of ​​a projection beam array field at a plane of a second beam forming element array of the optical device larger than an area of ​​the second beam forming element array, wherein the second group of optical elements is located in an optical coupling region between the second beam steering element array and the second beam forming element array of the optical device.

[0022] In some implementations, an area of ​​the beam array field at the plane of the first array of beam steering elements is larger than an area corresponding to beam forming elements in the first array of beam forming elements.

[0023] In some implementations, an area of ​​the beam array field at the plane of the second array of beam steering elements is larger than an area corresponding to beam forming elements in the second array of beam forming elements.

[0024] In some implementations, an optical device includes an optical port array; an array of beam forming elements optically coupled to the array of optical ports; an array of beam steering elements optically coupled to the array of beam forming elements; and a set of optical elements for making the size of a projected beam array field at a plane of the array of beam forming elements larger than the size of the array of beam forming elements, wherein the set of optical elements is located in an optical coupling region between the array of beam forming elements and the array of beam steering elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1A-1B is a diagram illustrating a conventional configuration of a high port count optical switch in a deployed arrangement.

[0026] Figure 2 is a diagram illustrating an example implementation of an optical switch that achieves reduced beam steering angle requirements and reduced optical port array and beam forming element array sizes without introducing crosstalk.

[0027] Figure 3 is a diagram of an illustrative example of a projection beam array field in the context of the optical switch described herein.

[0028] Figure 4is a diagram illustrating an example implementation of an optical switch that achieves reduced beam steering angle requirements and reduced optical port array and beam forming element array sizes.

[0029] Figure 5 is a diagram illustrating an example implementation of an optical switch that achieves reduced beam steering angle requirements. DETAILED DESCRIPTION

[0030] The following detailed description of example implementations refers to the accompanying drawings.The same reference numbers in different drawings may identify the same or similar elements.

[0031] A conventional configuration of high port count optical switches, such as optical cross connect switches (OXCs), is to direct a parallel collimated light beam to an array of tilted mirrors. Figure 1A is a diagram illustrating a conventional configuration of a high port count optical switch in an expanded arrangement. For visual clarity, the tilted mirrors in the mirror arrays MEMS1 and MEMS2 are Figure 1A is shown as a transmission beam steering element (so that the optical paths can be shown as non-overlapping). Figure 1A As shown, in a conventional optical switch, a light beam (indicated by a dotted line) is provided via a fiber array unit FAU1 and a microlens array MLA1. Figure 1A As shown, the topmost mirror t1 in the mirror array MEMS1 must be able to steer the beam within an angle range from zero angle (coupled to the topmost mirror t2 on the mirror array MEMS2) to -2θ (coupled to the bottommost mirror b2 on the mirror array MEMS2). Similarly, the bottommost mirror b1 on the mirror array MEMS1 should be able to steer the beam within an angle range from 0 (coupled to the bottommost mirror b2 on the mirror array MEMS2) to +2θ (coupled to the topmost mirror t2 on the mirror array MEMS2). Therefore, in a conventional optical switch, the required total beam steering range is 4θ.

[0032] One technique for reducing or minimizing the beam steering requirements of tilted mirrors in a mirror array is to use a lens between the two mirror arrays, an example of which is Figure 1B As shown. In this configuration, the lenses allow the beam incident on the mirror array to be collimated, which means that the fiber array unit (FAU) and microlens array (MLA) can be the same size as the mirror array while achieving a total beam steering angle range of 2θ. However, in this configuration, the lenses between the mirror arrays can be a source of crosstalk between the configured ports of the optical switch. For example, small defects in the optical surface of the lens can scatter light from one beam path to another, which means that crosstalk can be introduced, thereby degrading the performance of the optical switch.

[0033] It is worth noting that Figure 1A and Figure 1B The annotations "f" and "ω0" are used in Figure 1B In the optical switch shown, the beam waist (e.g., the location where the size of the light beam is the smallest) should be located at or near the plane of the mirror array MEMS1, so that the size of each tilted mirror of the mirror array is as small as possible (e.g., to simplify the manufacture of the mirror array MEMS1). Here, "ω0" represents the radius of the light beam at the beam waist. If the beam size and mirror size on the mirror array MEMS2 are expected to be the same as those on the mirror array MEMS1, the focal length of the lens should be equal to the Rayleigh distance of the light beam (assuming that the light beam is a Gaussian beam). Rayleigh distance is the distance at which the beam size increases to √2 of the beam size at the beam waist. Figure 1A In this case, it is assumed that the size of the tilted mirrors of the mirror array is the same as Figure 1B Therefore, if Figure 1A The optical switch should be used with Figure 1B If the same mirror array is used in , the beam waist should be located halfway between the two mirror arrays and the beam waist size should be smaller than Figure 1B The waist size in the reflector is smaller than √2, so that after propagating to the reflector in the reflector array, the beam size is Figure 1B Same as Figure 1A For a given mirror size in a conventional optical switch, the maximum spacing between mirror array MEMS1 and mirror array MEMS2 is obtained when the above condition is met (i.e., when the mirror array is located one Rayleigh distance from the beam waist). This results in Figure 1A The distance between the reflector array MEMS1 and the reflector array MEMS2 is equal to Figure 1B The focal length of the lens in is f. Therefore, Figure 1A The symbol "f" in the figure refers to the interval between the reflector array MEMS1 and the reflector array MEMS2. Figure 1B The same mirror array used in the . Note "f" and "ω0" in the following about Figure 2-Figure 5 The example implementations shown and described are similarly used.

[0034] Some implementations described herein provide an optical switch that includes an optical port array (e.g., a fiber array unit (FAU)), an array of beam forming elements optically coupled to the optical port array (e.g., a microlens array (MLA)), and an array of beam steering elements optically coupled to the beam forming element array (e.g., a microelectromechanical system (MEMS) mirror array). The optical switch also includes a set of optical elements located in an optical coupling region between the beam forming element array and the beam steering element array. In some implementations, the set of optical elements will cause the size of the projected beam array field at the plane of the beam forming element array to be larger than the size of the beam forming element array. In operation, the set of optical elements arranged in the optical coupling region between the beam forming element array and the beam steering element array can cause a light beam from a smaller size beam forming element array (and a smaller size optical port array) to be directed to the beam steering element array at a beam spacing that matches the pitch between the beam steering elements in the beam steering element array and at an appropriate beam angle, so that the beam steering requirement of the beam steering element array is minimized. That is, the optical switch described herein reduces the beam steering angle requirement of the beam steering element array (e.g., relative to the beam steering angle requirement of the beam steering element array). Figure 1A ), and no lenses are inserted between the beam steering element arrays, thereby avoiding the introduction of crosstalk (e.g., Figure 1B ). In addition, in some implementations, the optical switches described herein enable minimizing the beam steering requirements of the beam steering element array without increasing the size of the optical port array or the beam forming element array of the optical switch. More details are provided below.

[0035] Figure 2 is a diagram illustrating an example implementation of an optical switch 200 that achieves reduced beam steering angle requirements and reduced optical port array and beam forming element array sizes without introducing crosstalk. Figure 2 As shown, in one example implementation, the optical switch 200 includes a first optical port array 202a, a first beam forming element array 204a, a first set of optical elements 206a (e.g., including optical element 206a1 and optical element 206a2), a first beam steering element array 208a, a second beam steering element array 208b, a second set of optical elements 206b (e.g., including optical element 206b1 and optical element 206b2), a second beam forming element array 204b, and a second optical port array 202b. As further shown, in some implementations, the optical switch 200 may optionally include an aperture element 210. The elements of the optical switch 200 are described below, followed by an example of the operation of the optical switch 200.

[0036] The optical port array 202 is an optical fiber array that is used to couple light beams to or from the optical switch 200. For example, in some implementations, the first optical port array 202a may be an input FAU that couples light beams to the optical switch 200 (e.g., couples light beams from a set of input optical fibers), and the second optical port array 202b may be an output FAU that couples light beams out of the optical switch 200 (e.g., couples to a set of output optical fibers). In this implementation, the first optical port array 202a provides the set of light beams to the first beam forming element array 204a, and the second optical port array 202b receives the set of light beams after being collimated by the second beam forming element array 204b (e.g., the light beams are aligned with respect to the optical switch 200). Figure 2 Propagates from left to right). In some implementations, the optical port array 202 (e.g., the first optical port array 202a, the second optical port array 202b) may include a one-dimensional (1D) array, or may include a two-dimensional (2D) array. In some implementations, the optical port array 202 is optically coupled to the beam forming element array 204 (e.g., the first optical port array 202a is optically coupled to the first beam forming element array 204a, and the second optical port array 202b is optically coupled to the second beam forming element array 204b).

[0037] The beam forming element array 204 is an array of elements for collimating the set of light beams propagating through the optical switch 200. For example, the first beam forming element array 204a may include a first MLA including a microlens array for collimating the set of light beams provided by the first optical port array 202a, and the second beam forming element array 204b may include a second MLA including a microlens array for collimating the set of light beams to be provided to the second optical port array 202b (e.g., after being directed by the second beam steering element array 208b). In some implementations, the spacing and arrangement of the beam forming elements in the first beam forming element array 204a matches the spacing and arrangement of the optical ports in the first optical port array 202a (e.g., such that each optical port in the first optical port array 202a provides light to a corresponding beam forming element in the first beam forming element array 204a in a one-to-one manner). Similarly, the spacing and arrangement of the beam forming elements in the second array of beam forming elements 204b can match the spacing and arrangement of the optical ports in the second array of optical ports 202b (e.g., such that each optical port in the second array of optical ports 202b receives light from a corresponding beam forming element in the second array of beam forming elements 204b in a one-to-one manner). In some implementations, the array of beam forming elements 204 is optically coupled to the array of beam steering elements 208 (e.g., the first array of beam forming elements 204a is optically coupled to the first array of beam steering elements 208a, and the second array of beam forming elements 204b is optically coupled to the second array of beam steering elements 208b).

[0038] The set of optical elements 206 includes one or more optical elements for modifying the size or spacing of a set of light beams propagating through the optical switch 200. For example, the first set of optical elements 206a (e.g., optical element 206a1 and optical element 206a2) can include a first set of lenses for increasing the size and spacing of the set of light beams at the first beam steering element array 208a (relative to the size and spacing of the set of light beams at the first beam forming element array 204a). In some implementations, the increase in size and spacing provided by the first set of optical elements 206a matches the spacing between adjacent light beams in the set of light beams with the pitch between adjacent beam steering elements in the first beam steering element array 208a. As another example, the second set of optical elements 206b (e.g., optical element 206b1 and optical element 206b2) can include a second set of lenses for reducing the size and spacing of the set of light beams at the second beam forming element array 204b (relative to the size and spacing of the set of light beams at the second beam steering element array 208b). In some implementations, the size and spacing reduction performed by the second set of optical elements 206b causes the spacing between adjacent beams in the set of beams to match the pitch between adjacent beam-forming elements in the second array of beam-forming elements 204b.

[0039] In other words, the set of optical elements 206 may include one or more optical elements to make the area of ​​the projected beam array field at the plane of the beam forming element array 204 larger than the area of ​​the beam forming element array 204. The projected beam array field at a reference plane (e.g., the plane of the beam forming element array 204) may be determined by back-projecting the beams in the set of light beams along their incident directions and determining the smallest convex area containing the intersections of the projected beams with the reference plane. In addition, the set of optical elements 206 may make the area of ​​the beam array field at the plane of the beam steering element array 208 larger than the area corresponding to the beam forming elements in the beam forming element array 204.

[0040] Figure 3 is a diagram of an illustrative example of a projection beam array field in the context of an optical switch 200. Figure 3 In FIG. 1 , the light beams in a set of light beams pass through a set of optical elements 206a (e.g., a pair of lenses) and are incident on the beam steering element array 208a at corresponding angles. Here, the projected beam array field at the plane of the beam forming element array 204a is determined by projecting these light beams along their incident directions back to the plane of the beam forming element array 204a. Figure 3 As shown, the area of ​​the projected beam array field at the plane of the first beam forming element array 204a is larger than the area of ​​the first beam forming element array 204a. Therefore, in this example, the set of optical elements 206a causes the area of ​​the projected beam array field at the plane of the beam forming element array 204a to be larger than the area of ​​the beam forming element array 204a. It is worth noting that the projected beam array field is a geometric construction used to represent the range of angles incident on the beam steering element array, and is not a tangible element related to the operation or function of the optical switch 200. In addition, as Figure 3 As shown, the group of optical elements 206 can make the area of ​​the beam array field at the plane of the first beam steering element array 208a larger than the area corresponding to the beam forming elements in the first beam forming element array 204a. The second group of optical elements 206b can cause a similar effect. That is, the second group of optical elements 206b can make the area of ​​the projection beam array field at the plane of the second beam forming element array 204b larger than the area of ​​the second beam forming element array 204b, and can make the area of ​​the beam array field at the plane of the second beam steering element array 208b larger than the area corresponding to the beam forming elements in the second beam forming element array 204b.

[0041] As mentioned above, Figure 3 Other examples can be found in the Figure 3 Different from what is described.

[0042] Back to Figure 2In some implementations, a set of optical elements 206 is located in an optical coupling region between the beam forming element array 204 and the beam steering element array 208 (e.g., a first set of optical elements 206a is located in an optical coupling region between the first beam forming element array 204a and the first beam steering element array 208a, and a second set of optical elements 206b is located in an optical coupling region between the second beam forming element array 204b and the second beam steering element array 208b). In some implementations, a given set of optical elements 206 may include one or more lenses (e.g., Figure 2 Additionally or alternatively, a given set of optical elements 206 may include one or more curved mirrors, or another type of optical element capable of increasing or decreasing the size or spacing of the set of light beams.

[0043] The beam steering element array 208 includes an array of adjustable elements for directing (i.e., steering) the group of light beams within the optical switch 200. For example, the first beam steering element array 208a may include an array of beam steering elements associated with directing each light beam in the group of light beams toward the second beam steering element array 208b. In some implementations, the first beam steering element array 208a includes a plurality of independent beam steering elements for independently directing the light beams in the group of light beams. Similarly, the second beam steering element array 208b may include a plurality of independent beam steering elements for independently directing the light beams in the group of light beams. That is, each of the first beam steering element array 208 and the second beam steering element array 208 may include a plurality of independent beam steering elements for independently directing the light beams in the group of light beams. In some implementations, the first beam steering element array 208a is optically coupled to the second beam steering element array 208b.

[0044] In some implementations, the beam steering element array 208 (e.g., the first beam steering element 208a array, the second beam steering element array 208b) may include a tiltable MEMS mirror array, wherein each tiltable MEMS mirror may be used to direct one or more light beams incident thereon. In some implementations, the size (e.g., width, height, etc.) of the first beam steering element array 208a is larger than the corresponding size of the first optical port array 202a (i.e., the size of the first optical port array 202a is smaller than the corresponding size of the first beam steering element array 208a). Similarly, in some implementations, the size (e.g., width, height, etc.) of the second beam steering element array 208b is larger than the corresponding size of the second optical port array 202b (i.e., the size of the second optical port array 202b is smaller than the corresponding size of the second beam steering element array 208b). In some implementations, due to the increase and decrease in the size and spacing of the light beams provided by the above-mentioned set of optical elements 206, a relatively small optical port array 202 can be used.

[0045] The aperture element 210 is an optional element used to reduce crosstalk between light beams propagating through the optical switch 200. In some implementations, such as Figure 2 As shown, the aperture element 210 can be arranged in the optical coupling region between the second beam steering element array 208b and the second beam forming element array 204b. In some implementations, the aperture element 210 can be arranged at a position where all beams in the group of beams intersect. In this way, the aperture element 210 can reduce crosstalk between beam paths, especially during switch reconfiguration operations. For example, during a switch reconfiguration operation, when the beam steering elements in the first beam steering element array 208a are being reconfigured, the beams incident on the middle, already configured beam steering elements in the second beam steering element array 208b will be incident on the aperture element 210 at an off-axis position. Therefore, these beams will be blocked by the aperture element 210 (e.g., so that these beams will not be incident on the second beam forming element array 204b), which means that crosstalk is avoided. In some implementations, the second aperture element 210 can be arranged in the optical coupling region between the first beam forming element array 204a and the first beam steering element array 208a, such as when the optical switch 200 is a bidirectional optical switch.

[0046] In an example operation of the optical switch 200, the first optical port array 202a provides a set of light beams to the first beam forming element array 204a. The first beam forming element array 204a collimates the set of light beams provided by the first optical port array 202a. After the set of light beams are collimated by the first beam forming element array 204a, the first set of optical elements 206a increases the size and spacing of the set of light beams at the first beam steering element array 208a (relative to the size and spacing of the set of light beams at the first beam forming element array). That is, the first set of optical elements 206a can make the area of ​​the projected beam array field at the plane of the first beam forming element array 204a larger than the area of ​​the first beam forming element array 204a. In addition, the first set of optical elements 206a can make the area of ​​the beam array field at the plane of the first beam steering element array 208a larger than the area corresponding to the beam forming elements in the first beam forming element array 204a.

[0047] Then, the first beam steering element array 208a guides (e.g., based on the switching configuration) the group of light beams. Here, each beam steering element in the first beam steering element array 208a guides the light beam incident thereon toward the beam steering element in the second beam steering element array 208b. As described above, each beam steering element in the first beam steering element array 208a independently guides one or more light beams incident thereon. In some implementations, the beam waist of a given light beam in the group of light beams is located near the midpoint in the optical coupling region between the first beam steering element array 208a and the second beam steering element array 208b. After being guided by the first beam steering element array 208a, the second beam steering element array 208b further guides (e.g., based on the switching configuration) the group of light beams. Here, each beam steering element in the second beam steering element array 208b guides the light beam incident thereon toward the beam forming element in the second beam forming element array 204b. As described above, each beam steering element in the second beam steering element array 208b independently guides one or more light beams incident thereon. After being directed by the second beam steering element array 208b, the second set of optical elements 206b reduces the size and spacing of the set of light beams at the second beam forming element array 204b (relative to the size and spacing of the set of light beams at the second beam steering element array 208b). Then, the second beam forming element array 204b collimates the set of light beams after being reduced in size and spacing by the second set of optical elements 206b, and the second optical port array 202b receives the set of light beams after being collimated by the second beam forming element array 204b. Here, the second set of optical elements 206b can cause the area of ​​the projected beam array field at the plane of the second beam forming element array 204b to be larger than the area of ​​the second beam forming element array 204b. In addition, the second set of optical elements 206b can cause the area of ​​the beam array field at the plane of the second beam steering element array 208b to be larger than the area corresponding to the beam forming elements in the second beam forming element array 204b.

[0048] In the above operation of the optical switch 200, the light beam is converged onto the first beam steering element array 208a to minimize the required beam steering angle. In addition, the first set of optical elements 206 is used to increase the light beam size in the optical coupling region between the first optical port array 202a and the first beam steering element array 208a, which enables the use of a reduced size first optical port array 202a and a reduced size first beam forming element array 204a while also providing a low beam steering angle. In addition, there are no optical elements in the optical coupling region between the first beam steering element array 208a and the second beam steering element array 208b, thereby avoiding crosstalk while achieving the above benefits.

[0049] In some implementations, as described above, the first set of optical elements 206a is arranged in the optical coupling region between the first optical port array 202a and the first beam steering element array 208a (e.g., on the input side of the optical switch 200). As described above, this configuration is used to increase the beam size and spacing at the beam steering element array 208a (on the input side) (e.g., relative to the beam size and spacing at the first beam forming element array 204a), which means that the size (e.g., width, height) of the first optical port array 202a and the size of the first beam forming element array 204a can be reduced, so that the sizes of the first optical port array 202a and the first beam forming element array 204a are smaller than the corresponding sizes of the first beam steering element array 208a. Similarly, the second set of optical elements 206b is arranged in the optical coupling region between the second beam steering element array 208b and the second optical port array 202b (e.g., on the output side of the optical switch 200). As described above, this configuration is used to reduce (on the output side) the beam size and spacing at the second beam shaping element array 204b (e.g., relative to the beam size and spacing at the second beam steering element array 208b), which means that the size (e.g., width, height) of the second optical port array 202b and the size of the second beam shaping element array 204b can be reduced, so that the size of the second optical port array 202b and the second beam shaping element array 204b are smaller than the corresponding size of the second beam steering element array 208b. In addition, the set of optical elements 206a provides an angle for the beam on the beam steering element array 208a, which means that the beam steering angle requirement of the beam steering element array 208a is reduced.

[0050] Figure 2 One advantage of the configuration of the optical switch 200 shown is that such configuration reduces the beam steering requirements of the beam steering element arrays 208 (e.g., the required total beam steering angle is 2θ compared to 4θ). In some implementations, the beam steering requirement of a given beam steering element array 208 is approximately equal to half the size of the given beam steering element array 208 divided by the distance between the first beam steering element array 208a and the second beam steering element array 208b. In other words, the beam steering requirement can be such that, in a rest position (e.g., when a control voltage of 0 volts (V) is applied to the beam steering elements in a given beam steering element array 208), each beam steering element is to direct a corresponding light beam to approximately the same position on the other beam steering element array 208. Figure 2 Another advantage of the illustrated configuration of the optical switch 200 is that such configuration does not require any optical elements in the optical coupling region between the first beam steering element array 208a and the second beam steering element array 208b. Thus, crosstalk between the beam paths is avoided.

[0051] In some implementations, the number of adjustable parameters associated with the optical switch 200 is greater than the number of constraints, which provides flexibility in designing the optical switch 200 to achieve desired characteristics. Figure 2 As shown, the optical switch 200 may have five parameters that may be changed to achieve the above functions: focal length f1 (e.g., focal length of optical element 206a1, focal length of optical element 206b2), focal length f2 (e.g., focal length of optical element 206a2, focal length of optical element 206b1), distance d1 (e.g., distance between first beam forming element array 204a and optical element 206a1, distance between optical element 206b2 and second beam forming element array 204b), distance d2 (e.g., distance between optical element 206a1 and optical element 206a2, distance between optical element 206b1 and optical element 206b2), and distance d3 (e.g., distance between optical element 206a2 and first beam steering element array 208a, distance between second beam steering element array 208b and optical element 206b1). Constraints will include the position and angle of the beam at the beam steering element 208a, and the size and position of the beam waist. Here, because there are more adjustable parameters than constraints, and there is at least one free parameter, for example, distance d3 can be fixed so that optical element 206a2 is a preferred or convenient distance from first beam steering element array 208a (and so that optical element 206b1 is a preferred or convenient distance from second beam steering element array 208b), and the remaining parameters can be optimized to obtain a set of desired characteristics.

[0052] As mentioned above, Figure 2 Other examples can be found in the Figure 2 Different from what is described. Figure 2 The number and arrangement of the elements shown are provided as examples only. Figure 2 There may be more elements, fewer elements, different elements, or differently arranged elements than shown. Figure 2 Two or more of the elements shown may be implemented in a single element, or Figure 2 The single element shown may be implemented as multiple distributed elements. Additionally or alternatively, Figure 2 The illustrated set of elements (e.g., one or more elements) may perform the operations described as being performed by Figure 2 Another group of components is shown performing one or more functions.

[0053] Figure 4 is a diagram illustrating an example implementation of an optical switch 200 that achieves reduced beam steering angle requirements and reduced optical port array and beam forming element array sizes. Figure 4As shown, in some implementations, the optical switch 200 may include an optical element 402 located in an optical coupling region between the first beam steering element array 208a and the second beam steering element array 208b. The optical element 302 may be, for example, a lens (e.g., a Fourier lens). It is worth noting that Figure 4 The configuration of the optical switch 200 shown is similar to Figure 2 The configuration of the optical switch 200 shown is different in that the light beam incident on the first beam steering element array 208a is parallel and the beam waist is located at the beam steering element array 208. Figure 4 The optimization conditions for each set of optical elements 206 in the configuration shown are different from Figure 2 Optimization conditions for the configuration shown.

[0054] One solution is that the magnification provided by the first set of optical elements 206a located in the optical coupling region between the first optical port array 202a and the first beam steering element array 208a is equal to f1 / f2, the distance between the first optical port array 202a and the optical element 206a1 is equal to f1, the distance between the optical element 206a1 and the optical element 206a2 is equal to f1+f2, and the distance between the optical element 206a2 lens and the first beam steering element array 208a is equal to f2, where f1 and f2 are the focal lengths of the optical element 206a1 and the optical element 206a2, respectively. This configuration is advantageous because any fiber position error in the optical port array 202a (resulting in a beam angle error after being collimated by the first beam forming element array 204a) can be corrected by adjusting the corresponding beam steering element angle, which can be done during calibration of the optical switch 200. In addition, Figure 4 The configuration of the optical switch 200 in achieves low insertion loss because the aperture of the first beam steering element array 208a is located at the image of the aperture of the first beam forming element array 204a, which means that after the beam is clipped by the aperture of the first beam forming element array 204a, there is no additional light loss in the beam clipping performed at the first beam steering element array 208a. In some implementations, the configuration of the optical switch 200 including the optical element 402 can be used when, for example, the risk of crosstalk is acceptable or the crosstalk can be controlled or eliminated in other ways.

[0055] As mentioned above, Figure 4 Other examples can be found in the Figure 4 Different from what is described. Figure 4 The number and arrangement of the elements shown are provided as examples only. Figure 4 There may be more elements, fewer elements, different elements, or differently arranged elements than shown. Figure 4Two or more of the elements shown may be implemented in a single element, or Figure 4 The single element shown may be implemented as multiple distributed elements. Additionally or alternatively, Figure 4 The illustrated set of elements (e.g., one or more elements) may perform the operations described as being performed by Figure 4 Another group of components is shown performing one or more functions.

[0056] Figure 5 is a diagram illustrating an example implementation of an optical switch 200 that achieves a reduced beam steering angle requirement. Another technique for reducing the beam steering angle requirement of the beam steering element array 208 is to direct the light beams incident on the first beam steering element array 208 so that at zero steering angle, each light beam is directed to a center beam steering element on the second beam steering element array 208. Figure 5 is a diagram illustrating such a configuration of the optical switch 200 .

[0057] In this configuration, an input light beam is incident on the first beam steering element array 208a at an angle such that if the beam steering elements in the beam steering element array 208a are stationary (e.g., have zero tilt), the light beam incident thereon is directed to the center beam steering element in the beam steering element array 208b. In this implementation, in order to direct the light beam to the topmost beam steering element on the second beam steering element array 208b, the beam steering elements in the first beam steering element array 208 may need to steer the light beam to an angle corresponding to +θ. Similarly, in order to steer the light beam to the bottommost beam steering element on the beam steering element array 208b, the beam steering elements may need to steer the light beam to an angle corresponding to -θ. This condition applies to each beam steering element on the first beam steering element array 208a, and therefore the total beam steering angle is 2θ. An advantage of this configuration is that the number of elements in the optical switch is reduced, which can reduce the cost of the optical switch 200 or the complexity of assembling the optical switch 200. However, it is worth noting that in such a configuration, the optical port array 202 and the beam forming element array 204 need to be appropriately sized (eg, the size of the optical port array 202 and the beam forming element array 204 may need to be increased).

[0058] As mentioned above, Figure 5 Other examples can be found in the Figure 5 Different from what is described. Figure 5 The number and arrangement of the elements shown are provided as examples only. Figure 5 There may be more elements, fewer elements, different elements, or differently arranged elements than shown. Figure 5 Two or more of the elements shown may be implemented in a single element, or Figure 5The single element shown may be implemented as multiple distributed elements. Additionally or alternatively, Figure 5 The illustrated set of elements (e.g., one or more elements) may perform the operations described as being performed by Figure 5 Another group of components is shown performing one or more functions.

[0059] It is worth noting that, for the sake of clarity, Figure 2-Figure 5 The optical axis of the optical switch 200 is depicted in a linearly deployed orientation. In a physical implementation, any one or more of the elements along the optical path of the optical switch 200 can be configured to deflect or reflect the optical path to fold or multiply the optical path of the folded optical switch 200. Such an implementation can be used to reduce the actual size or dimensions of the optical switch 200 and / or may result in some physical overlap of the referenced "areas" of the optical switch 200. However, in combination Figure 2-Figure 5 The linear descriptions provided and the functional roles of the individual regions of the optical switch 200 herein maintain their properties even in the presence of such optical folding and / or overlapping. Thus, in some implementations, the first beam steering element array 208a and / or the second beam steering element array 208b may include reflective beam steering element arrays. In one example, both the first beam steering element array 208a and the second beam steering element array 208b are reflective beam steering element arrays (e.g., such that a z-shaped light path is formed in the optical switch 200). Similarly, in some implementations, one or more optical elements in the first set of optical elements 206a (e.g., one or more optical elements located in an optical coupling region between the first beam forming element array 204a and the first beam steering element array 208a) may be reflective optical elements, and / or one or more optical elements in the second set of optical elements 206b (e.g., one or more optical elements located in an optical coupling region between the second beam steering element array 208b and the second beam forming element array 204b) may be reflective optical elements. For example, such an implementation may be used to further fold the optical path of the optical switch 200 (eg, to reduce or control the physical size and dimensions of the optical switch 200).

[0060] The above disclosure provides illustration and description, but is not intended to be exhaustive or to limit the implementation to the precise form disclosed. Modifications and variations may be made based on the above disclosure, or may be obtained from the practice of the implementation. In addition, any implementation described herein may be combined, unless the above disclosure explicitly provides reasons why one or more implementations cannot be combined.

[0061] Although the specific combination of features is cited in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of various implementations. In fact, many of these features can be combined in a manner that is not specifically cited in the claims and / or is not disclosed in the specification. Although each dependent claim listed below can only directly depend on one claim, the disclosure of various implementations includes the combination of each dependent claim with each other claim in the claim set. As used herein, the phrase "at least one" in the referenced item list refers to any combination of these items, including single members. For example, "at least one of a, b or c" is intended to cover a, b, c, ab, ac, bc and abc, and the combination of multiple items in the same item.

[0062] When an element or one or more elements (e.g., an optical element, one or more optical elements, or a group of optical elements) is described or claimed (either within a single claim or across multiple claims) as performing multiple operations or being configured to perform multiple operations, such language is intended to broadly cover a variety of architectures and environments. For example, unless otherwise expressly required (e.g., via the use of "first element" and "second element" or other language that distinguishes elements in the claims), the language is intended to cover a single element performing or being configured to perform all operations, a group of elements collectively performing or being configured to perform all operations, a first element performing or being configured to perform a first operation and a second element performing or being configured to perform a second operation, or any combination of elements performing or being configured to perform the operations. For example, when a claim is of the form "One or more elements are configured to: perform X; perform Y; perform Z," the claim should be interpreted as "One or more elements are configured to perform X; one or more (possibly different) elements are configured to perform Y; and one or more (possibly different) elements are configured to perform Z."

[0063] Unless explicitly stated, any element, behavior or instruction used in this article should not be interpreted as critical or essential. In addition, as used in this article, the article "one" and "an" are intended to include one or more projects, and can be used interchangeably with "one or more". In addition, as used in this article, the article "said" is intended to include one or more projects quoted in combination with the article "said", and can be used interchangeably with "one or more". In addition, the word "set" used in this article is intended to include one or more projects (for example, a combination of related projects, unrelated projects, or related and unrelated projects), and can be used interchangeably with "one or more". If only one project is intended to be used, the phrase "only one" or similar language is used. In addition, as used in this article, the term "having", "having", "containing" etc. is intended to be an open term. In addition, unless otherwise explicitly stated, the word "based on" is intended to represent "at least partially based on". In addition, as used in this article, the term "or" is inclusive when used in series, and can be used interchangeably with "and / or", unless otherwise explicitly stated (for example, if used in combination with "any one of ... or "only one of ... "). Additionally, for ease of description, spatially relative terms (such as "below," "lower," "above," "upper," etc.) may be used herein to describe the relationship of one element or feature to other elements or features shown in the figures. Spatially relative terms are intended to encompass different orientations of the device, equipment, and / or elements in use or operation in addition to the orientations shown in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein may be interpreted accordingly.

Claims

1. An optical switch, comprising: a first optical port array; a first array of beam-forming elements, wherein the first array of optical ports is optically coupled to the first array of beam-forming elements; a first array of beam steering elements, wherein the first array of beam shaping elements is optically coupled to the first array of beam steering elements; a first set of optical elements for making the area of ​​the projection beam array field at the plane of the first array of beam forming elements larger than the area of ​​the first array of beam forming elements, wherein the first group of optical elements is located in an optical coupling region between the first array of beam forming elements and the first array of beam steering elements; a second array of beam steering elements, wherein the first array of beam steering elements is optically coupled to the second array of beam steering elements; a second array of beam forming elements, wherein the second array of beam steering elements is optically coupled to the second array of beam forming elements; as well as A second array of optical ports, wherein the second array of beam shaping elements is optically coupled to the second array of optical ports.

2. The optical switch of claim 1, wherein an area of ​​a beam array field at a plane of the first array of beam steering elements is larger than an area corresponding to beam forming elements in the first array of beam forming elements.

3. The optical switch of claim 1, wherein the first set of optical elements provides a beam spacing that matches a pitch between adjacent beam steering elements in the first array of beam steering elements.

4. The optical switch according to claim 1 further includes a second group of optical elements, which are used to make the area of ​​the projection beam array field at the plane of the second beam forming element array larger than the area of ​​the second beam forming element array, wherein the second group of optical elements is located in the optical coupling region between the second beam steering element array and the second beam forming element array.

5. The optical switch of claim 4, wherein an area of ​​a beam array field at a plane of the second array of beam steering elements is larger than an area corresponding to beam forming elements in the second array of beam forming elements.

6. The optical switch of claim 4, wherein the second set of optical elements provides a beam spacing that matches a pitch between adjacent beam forming elements in the second array of beam forming elements.

7. An optical switch according to claim 1, wherein the beam steering requirement associated with the first beam steering element array is approximately equal to half the size of the second beam steering element array divided by the distance between the first beam steering element array and the second beam steering element array.

8. The optical switch of claim 1, wherein in a rest position, each beam steering element in the first array of beam steering elements is configured to direct a corresponding light beam to approximately the same position on the second array of beam steering elements.

9. The optical switch of claim 1, wherein a beam waist of a given optical beam propagating in the optical switch is located near a midpoint between the first array of beam steering elements and the second array of beam steering elements.

10. The optical switch of claim 1, wherein dimensions of the first array of beam shaping elements are smaller than corresponding dimensions of the first array of beam steering elements.

11. The optical switch of claim 1, further comprising an aperture element located in an optical coupling region between the second array of beam steering elements and the second array of beam forming elements.

12. The optical switch according to claim 1 further includes a Fourier lens, which is located in the optical coupling region between the first beam steering element array and the second beam steering element array, wherein the beam steering requirement associated with the first beam steering element array is approximately equal to half the size of the second beam steering element array divided by the focal length of the Fourier lens.

13. The optical switch of claim 12, wherein a beam waist of a given optical beam propagating in the optical switch is located approximately at the first array of beam steering elements and approximately at the second array of beam steering elements.

14. The optical switch of claim 1, wherein the first array of beam steering elements and the second array of beam steering elements each comprise a plurality of independent beam steering elements for independently directing light beams.

15. The optical switch of claim 1, wherein at least one of the first beam steering element array or the second beam steering element array is a reflective beam steering element array.

16. The optical switch of claim 1, wherein at least one optical element of the first set of optical elements located in an optical coupling region between the first array of beam shaping elements and the first array of beam steering elements is a reflective optical element.

17. An optical switch, comprising: a first set of optical elements for making the area of ​​the projection beam array field at the plane of the first array of beam-forming elements of the optical device larger than the area of ​​the first array of beam-forming elements, wherein the first set of optical elements is located in an optical coupling region between the first array of beam forming elements and a first array of beam steering elements of the optical device; as well as a second set of optical elements for making the area of ​​the projection beam array field at the plane of the second array of beam-forming elements of the optical device larger than the area of ​​the second array of beam-forming elements, The second group of optical elements is located in an optical coupling region between a second beam steering element array and a second beam forming element array of the optical device.

18. The optical switch of claim 17, wherein an area of ​​a beam array field at a plane of the first array of beam steering elements is larger than an area corresponding to beam forming elements in the first array of beam forming elements.

19. The optical switch of claim 17, wherein an area of ​​a beam array field at a plane of the second array of beam steering elements is larger than an area corresponding to beam forming elements in the second array of beam forming elements.

20. An optical device comprising: Optical port array; an array of beam forming elements optically coupled to the array of optical ports; an array of beam steering elements optically coupled to the array of beam forming elements; as well as a set of optical elements for making the size of the projection beam array field at the plane of the beam forming element array larger than the size of the beam forming element array, Wherein the set of optical elements is located in an optical coupling region between the array of beam forming elements and the array of beam steering elements.

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