Interlocked N*N wavelength selective switch

Abstract

An interlocked N * N wavelength selective switch (WSS) includes a fast input port, a fast output port, a passive optical system, an array of switching elements, and N pairs of insert and drop ports. In each pair, the insertion port and the corresponding drop port are arranged relative to the fast input port and the fast output port, the interlocked N * N WSS is configured such that signals can be simultaneously reflected from the insertion port to the fast output port and from the fast input port to the corresponding drop port by the same switching element through the passive optical system, thereby enabling the interlocked N * N WSS to simultaneously insert and drop signals in the same wavelength band, the switch array is coupled to the port without requiring two dual 1 * N WSSs or an active element (e.g., an N-element MEMS switch array) between the switch array and the port.

Description

Technical Field

[0001] This disclosure relates to wavelength selective switches. Background Technology

[0002] Conventional optical add-drop multiplexers (OADMs) are typically implemented using dual 1×N wavelength selective switches (WSS) (i.e., “output” WSS and “insert” WSS) or M×N WSSs with M switch windows and N element microelectromechanical systems (MEMS) switch arrays.

[0003] Using dual WSS introduces significant connection and switching losses, thus requiring amplifiers and pumps to amplify unintentionally attenuated signals, increase power to provide the amplification, and additional power management to manage the increased power.

[0004] Meanwhile, the N-element MEMS switch arrays used in conventional M×N WSS modules make these modules more complex, bulky, and expensive, and the insertion loss is inherently higher due to the multi-step coupling within the module.

[0005] The subject of this disclosure is intended to overcome one or more of the problems set forth above, or at least reduce the impact of one or more of the problems. Summary of the Invention

[0006] An interlocked N×N wavelength selective switch (WSS) includes a fast input port, a fast output port, a passive optical system, an array of switching elements, and N pairs of insertion and output ports. In each pair, the insertion port and the corresponding output port are arranged relative to the fast input port and the fast output port, such that a signal can be simultaneously reflected from the insertion port to the fast output port and from the fast input port to the corresponding output port by the same switching element through the passive optical system. This allows the interlocked N×N WSS to simultaneously insert and output signals in the same wavelength band without requiring two dual 1×N WSSs or active elements (e.g., an N-element MEMS switch array) between the switch array and the ports.

[0007] By eliminating the need for dual conventional 1×N WSSs, implementations of interlocked N×N WSSs can be provided in a simpler, more compact package than conventional OADMs, with insertion and switching losses introduced by conventional OADMs reduced by up to half (e.g., as low as a single 1×N WSS). Furthermore, by eliminating the need for active components (such as N-element MEMS switch arrays used in conventional M×N WSS modules) between the optical array and the switching elements, implementations of interlocked N×N WSSs are simpler and less expensive (while introducing less insertion loss) compared to conventional M×N WSS modules.

[0008] In embodiments, the ports of the interlocked N×N WSS can be substantially aligned along a displacement axis (e.g., orthogonal to the emission axis), and the switching elements can be configured to reflect the diffracted light signal and displace the reflected light signal along the displacement axis. In those embodiments, for example, the insert port and the corresponding output port of each insert-output pair can be arranged along the displacement axis such that the angular difference between the diffracted beams output by the passive optics system from the fast input port and the insert port is equal to the angular difference between the reflected beams output by the passive optics system to the fast input port and the corresponding output port, reflected by any of the switching elements in the switching elements.

[0009] In an embodiment, each switching element can be configured such that, in one state, the switching element is configured to reflect a diffracted light signal received from the fast input port (via the passive optical system) to the fast output port (via the passive optical system), and in another state, the switching element is configured to simultaneously reflect a diffracted light signal received (via the passive optical system) from the insertion port of one of the N insertion-output pairs to the fast output port (via the passive optical system), and reflect a diffracted light signal received from the fast input port (via the passive optical system) to the corresponding output port of the insertion-output pair (via the passive optical system). For example, each switching element can have N+1 potential states, wherein the switching element is configured to pass a signal from the fast input port to the fast output port, or simultaneously insert a signal from one of the N insertion-output pairs and output the signal to the insertion-output pair.

[0010] In some embodiments, the interlocked N×N WSS may include a controller configured (e.g., by setting the state of one or more of the switching elements) to selectively pass a signal from the fast input port to the fast output port, or simultaneously insert and extract signals. In some embodiments, the passive optical system includes a dispersive element that splits the input optical signal into diffracted light signals in a plurality of wavelength bands; each switching element receives and reflects the diffracted light signal in one of the plurality of wavelength bands; and the controller is configured to selectively pass, insert, and extract signals in each wavelength band by controlling the state of the switching element that receives the diffracted light signal in each wavelength band.

[0011] In some embodiments, the interlocked N×N WSS is configured to insert a signal in the wavelength band received through the insert port of one of the N insert-output pairs; and to output the signal in the wavelength band (received through the fast input port) to the corresponding output port of the insert-output pair. For example, in some embodiments of these embodiments, the signal in the wavelength band (received through the insert port and the fast input port) can be diffracted and reflected by the same switching elements. Attached Figure Description

[0012] Referring to the accompanying drawings will provide a better understanding of aspects of the exemplary embodiments. The components in the drawings are not necessarily drawn to scale, but rather the focus is on illustrating the principles of the exemplary embodiments.

[0013] Figure 1A This is a simplified block diagram of a conventional 1×N wavelength selective switch (WSS).

[0014] Figure 1B yes Figure 1A Orthogonal view of a standard 1×N WSS.

[0015] Figure 1C yes Figure 1A Another view of the regular 1×N WSS.

[0016] Figure 1D yes Figure 1A Another view of the regular 1×N WSS.

[0017] Figure 1E yes Figure 1A Another view of the regular 1×N WSS.

[0018] Figure 2A This is a block diagram of a conventional optical add-drop multiplexer (OADM).

[0019] Figure 2B yes Figure 2A Another diagram of a conventional interpolation OADM.

[0020] Figure 2C yes Figure 2A Another diagram of a conventional interpolation OADM.

[0021] Figure 2D yes Figure 2A Another diagram of a conventional interpolation OADM.

[0022] Figure 2E yes Figure 2A Another diagram of a conventional interpolation OADM.

[0023] Figure 2F yes Figure 2AAnother diagram of a conventional interpolation OADM.

[0024] Figure 2G yes Figure 2A Another diagram of a conventional interpolation OADM.

[0025] Figure 2H yes Figure 2A Another diagram of a conventional interpolation OADM.

[0026] Figure 3A This is a block diagram of an interlocked N×N WSS according to an exemplary embodiment.

[0027] Figure 3B This is another diagram of an interlocked N×N WSS according to an exemplary embodiment.

[0028] Figure 3C This is another diagram of an interlocked N×N WSS according to an exemplary embodiment.

[0029] Figure 3D This is another diagram of an interlocked N×N WSS according to an exemplary embodiment.

[0030] Figure 3E This is another diagram of an interlocked N×N WSS according to an exemplary embodiment.

[0031] Figure 3F This is another diagram of an interlocked N×N WSS according to an exemplary embodiment.

[0032] Figure 3G This is another diagram of an interlocked N×N WSS according to an exemplary embodiment.

[0033] Figure 3H This is another diagram of an interlocked N×N WSS according to an exemplary embodiment.

[0034] Figure 3I This is another diagram of an interlocked N×N WSS according to an exemplary embodiment.

[0035] Figure 3J This is another diagram of an interlocked N×N WSS according to an exemplary embodiment.

[0036] Figure 3K This is another diagram of an interlocked N×N WSS according to an exemplary embodiment. Detailed Implementation

[0037] Reference is now made to the accompanying drawings, which illustrate various views of exemplary embodiments. In the drawings and description herein, certain terminology is used merely for convenience and should not be construed as limiting the embodiments of the invention. Furthermore, in the drawings and the following description, the same reference numerals consistently denote the same elements.

[0038] Figure 1A This is a simplified block diagram of a standard 1×N wavelength selective switch (WSS) 100. Figure 1A In this example, WSS100 includes an optical array 120, a collimating optics 140, a dispersive element 150, a focusing optics 170, and a switching element array 190. The collimating optics 140, the dispersive element 150, and the focusing optics 170 are collectively referred to below as the passive optical system 180.

[0039] As described in more detail below, WSS100 can be used as an "insertion" WSS or an "output" WSS. When used as an output WSS, one port of optical array 120 is used as an input port (often referred to as the "fast input" port), while the remaining ports are used as output ports ("fast output" ports and multiple output ports). Alternatively, when WSS100 is used as an insertion WSS, one of the ports is used as an output port ("fast output" port), while the remaining ports of optical array 120 are used as input ports ("fast input" ports and multiple insertion ports).

[0040] When used as input ports, each port of the optical array 120 is along the emission axis (in... Figure 1A-1E An input optical signal 122 is emitted (arbitrarily labeled as the 'z' axis). A collimating optics device 140 collimates the input optical signal 122 to form a collimated optical signal 141, which is then transmitted to a dispersive element 150. The dispersive element 150 diffracts the collimated optical signal 141 according to wavelength to form a plurality of diffracted beams 160, each of which lies within a wavelength band. For example, in... Figure 1A In this example, the diffracted beam 160 includes a diffracted beam 161 within wavelength band λ_1, a diffracted beam 162 within wavelength band λ_2, and a diffracted beam 163 within wavelength band λ_3. The focusing optics 170 then focuses each diffracted beam 160 onto a switching element 190.

[0041] Each switching element 190 receives a diffracted beam 160 within a wavelength band. Figure 1A In an example, switching element 190 may include a first switching element 191 receiving a diffracted beam 161 within wavelength band λ_1, a second switching element 192 receiving a diffracted beam 162 within wavelength band λ_2, and a third switching element 193 receiving a diffracted beam 163 within wavelength band λ_3. Switching element 190 can then be used to selectively control each wavelength band of the input optical signal 122, as described below. Figure 1B-1E As described.

[0042] Figure 1B-1EThis is an orthographic view of the example WSS100. For clarity, the individual components of the passive optical system 180 have been omitted. Figure 1A-1E In this example, the ports of the optical array 120 are along what is referred to herein as the "displacement axis" (in... Figure 1A-1E The axis arbitrarily labeled as the 'y' axis is orthogonal to the launch axis. Figure 1A-1E The switching element 190 is arranged along the 'z' axis. The switching element 190 reflects the diffracted beam 160 so that it can be transmitted back to the optical array 120 via the passive optical system 180. Simultaneously, as described below, the switching element 190 can be used to move each wavelength band along the displacement axis (…). Figure 1A-1E The 'y' axis is selectively shifted to selectively control each wavelength band.

[0043] Figure 1B-1C This demonstrates the use of WSS100 as a split WSS. When used as... Figure 1B-1C When the WSS is split as shown, the optical array 120 includes a fast input port 121, a fast output port 123, and multiple output ports 131, 132, 133, etc. (collectively referred to herein as one or more output ports 130). The switching element 190 can then be used to selectively transmit or split signals according to wavelength.

[0044] Each switching element 190 can be placed in one of at least two states (referred herein to as a transfer state α_0 and at least one output state α_N). Each switching element 190 reflects the diffracted beam 160 at an angle depending on the state α of the switching element 190. For example, as Figure 1B As shown, by placing the switching element 190 in the transmission state α_0, the switching element can be used to transmit the diffracted beam 160 received by the switching element 190 to the fast output port 123, wherein the diffracted beam 160 received by the switching element 190 from the fast input port 121 is reflected to the fast output port 123 by the passive optical system 180. The passive optical system 180 combines all the diffracted beams 160 reflected to the fast output port 123 by each switching element 190 to form an output optical signal 124, which is provided to the fast output port 123 and output therefrom.

[0045] Each switching element 190 can be positioned in a diverging state α_N to diverge the diffracted beam 160 received by the switching element 190 from the fast input port 121, wherein the diffracted beam 160 received by the switching element 190 from the fast input port 121 is reflected to one of the diverging ports 130. In a diverging WSS with N diverging ports 130, each switching element 190 can be configured such that it can be positioned in any of the N diverging states α_N, where each of the N diverging states α_N corresponds to one of the N diverging ports 130. For example, in Figure 1C In one example, the switching element 193 can be selectively separated from the diffracted beam 163 received by the switching element 193 by being placed in state α_3, wherein the diffracted beam 163 received by the switching element 193 from the fast input port 121 is reflected to the output port 133.

[0046] Figure 1D-1E This demonstrates the use of WSS100 as an inserted WSS. When used as such... Figure 1D-1E When inserting a WSS as shown, the optical array 120 includes a fast output port 123, a fast input port 121, and multiple insertion ports 111, 112, 113, etc. (collectively referred to herein as one or more insertion ports 110). As in the above example of inserting a WSS, the signal from the optical array 120 is diffracted to each switching element 190 according to the wavelength band. Each switching element 190 can then be used to reflect the diffracted beam 160 within the wavelength band to the fast output port 123.

[0047] However, in the inserted WSS, each switching element 190 is used to reflect the signal from the fast input port 121 (e.g., as shown in the image). Figure 1D (as shown) or a diffracted beam 160 from an insertion port 110 (e.g., a diffracted beam 163 from an insertion port 113, such as...) Figure 1E (As shown). Similar to the WSS example described above, each switching element 190 can be configured such that it can be placed in a pass state α_0 (where the fast input port 121 is reflected by the diffracted beam 160 to the fast output port 123) or one or more insertion states α_N (where the fast output port 123 is reflected by the diffracted beam 160 from one of the insertion ports 110).

[0048] Theoretically, any switching element 190 can be used to reflect signals between any two ports of the optical array 120. However, in practice, optical add-drop multiplexers (OADMs) are often used to simultaneously insert and extract signals in the same wavelength band. Meanwhile, in Figure 1A-1EIn a typical 1×N WSS100, all signals within each wavelength band (from any / all ports of the optical array 120) are diffracted to the same switching element 190 (e.g., Figure 1A As shown), the switching element is in only one state α at any given time (e.g., Figure 1B-1E (As shown). Therefore, two dual conventional 1×N wavelength WSS100s are typically used to form an optical add-drop multiplexer.

[0049] Figure 2A-2H This is a diagram of a conventional OADM 200 including dual 1×N wavelength selection switches 100 (output WSS100A and insertion WSS100B) connected via optical link 220. Figure 2A-2H In the example, the WSS100A includes a fast input port 121A, a fast output port 123A, and multiple output ports 130; the WSS100B includes a fast input port 121B, a fast output port 123B, and multiple insertion ports 110; and the fast output port 123A of the WSS100A is connected to the fast input port 121B of the WSS100B via an optical link 220.

[0050] Figure 2B An example of a typical OADM 200 signal transmission is shown (i.e., without the signal in the wavelength band being separated and / or inserted). For example... Figure 2B As shown, a conventional OADM 200 transmits signals as follows: First, the switching element 190A of the split WSS100A is used to reflect the signal from the fast input port 121A of the split WSS100A to the fast output port 123A. Then, the signal is transmitted from the fast output port 123A of the split WSS100A to the fast input port 121B of the split WSS100B via the optical link 220. Finally, the switching element 190B inserted into the WSS100B is used to reflect these signals from the fast input port 121B of the inserted WSS100B to the fast output port 123B of the inserted WSS100B.

[0051] like Figure 2C-2D As shown, the signal in wavelength band λ_1 (as described above, diffracted onto switching elements 191A and 191B) can be simultaneously split off by WSS100A to output port 131 and inserted by WSS100B from insertion port 111. Similarly, as Figure 2E-2F As shown, the signal in wavelength band λ_2 can be simultaneously split from the WSS100A to the output port 132 by the switching element 192A, and inserted from the insertion port 112 by the switching element 192B that inserts the WSS100B. Finally, as Figure 2G-2HAs shown, the signal in wavelength band λ_3 can be simultaneously split from the WSS100A to the output port 133 by the switching element 193A that splits out WSS100A, and inserted from the insertion port 113 by the switching element 193B that inserts into WSS100B.

[0052] Figures 3A-3H This is a diagram illustrating an interlocked N×N wavelength selection switch (WSS) 300 according to an exemplary embodiment.

[0053] exist Figures 3A-3H In one embodiment, the interlocked WSS 300 includes an optical array 120, which includes an optical input array 310 and an optical output array 330. The optical input array 310 includes a fast input port 121 and N insertion ports 110. The optical output array 330 includes a fast output port 123 and N output ports 130. The insertion ports 110 and output ports 130 form N insertion-output pairs 320, each insertion-output pair including an insertion port 110 and an associated output port 130.

[0054] Unlike the conventional 1×N WSS100 described above, the interlocked N×N WSS 300 can simultaneously insert and extract signals in the same wavelength band using only one switching element array 190 as described below, eliminating the need for two dual 1×N WSS (or MEMS switch arrays), reducing connection and switching losses, and providing many benefits outlined below.

[0055] like Figure 3B As shown, the interlocked N×N WSS 300 can be used to transmit signals by reflecting signals in any wavelength band from a fast input port 121 to a fast output port 123 using switching elements 190, which receive diffracted beams 160 within the wavelength band from a passive optical system 180. The passive optical system 180 is then configured to combine all diffracted beams 160 reflected by each switching element 190 to the fast output port 123 to form an output optical signal 124, which is provided to and output from the fast output port 123.

[0056] In other words, such as Figure 3C-3K As shown, the interlocked N×N WSS 300 can simultaneously insert and extract signals in the same wavelength band because the insertion port 110 and the output port 130 form N insertion-output pairs 320, which are relative to the fast input port 121 and the fast output port 123 along the displacement axis ( Figure 3B-3E The arrangement of the 'y' axis (e.g., in the diagram) allows signals to be simultaneously reflected from the fast input port 121 to the output port 130 and from the corresponding insertion port 110 to the fast output port 123 by a single switching element 190. For example... Figure 3C-3EAs shown more specifically, each insertion port 110 and output port 130 of each insertion-output pair 320 is arranged along the displacement axis such that the angular difference Δθ between the diffracted beams 161 received from the fast input port 121 and output port 110 (via the passive optical system 180) is the same as the angular difference Δθ between the reflected beams output (via the passive optical system 180) to the fast output port 121 and the corresponding output port 130. Therefore, a single switching element 190 in state α can simultaneously receive the diffracted beams 160 as... Figure 3D As shown, the signal is reflected from the fast input port 121 to the output port 130, and as... Figure 3E The diagram shows the reflection from the corresponding insert port 110 of the insert-output pair 320 to the fast output port 123.

[0057] Therefore, unlike the conventional 1×N WSS100 described above, the interlocked N×N WSS 300 provides the ability to simultaneously insert and extract signals in the same wavelength band, even if the signals are diffracted to the same switching element 190 as described above. Figure 3F-3G As shown, for example, insertion port 111 and output port 131 can form an insertion-output pair 321, which can be used to simultaneously insert and output signals diffracted to the first switching element 191 in the first wavelength band λ_1. Then, by moving to the state ( Figure 3G In the first wavelength band λ_1, the first switching element 191 can be used to simultaneously insert and extract signals in the first wavelength band λ_1, thereby reflecting them from the fast input port 121 to the output port 131 via the diffracted beam 161, and from the corresponding insertion port 111 to the fast output port 123. Simultaneously, as with a conventional OADM 200, the first switching element 191 is activated by moving to a state (α_1). Figure 3B The signal in the first wavelength band λ_1 is transmitted via α_0 in the diffracted beam 161 from the fast input port 121 to the fast output port 123.

[0058] Similarly, such as Figure 3H-3I As shown, the insertion port 112 and the output port 132 can form an insertion-output pair 322, which can be used to move the second switching element 192 to a state ( Figure 3I The signal diffracted to the second switching element 192 in the second wavelength band λ_2 is selectively inserted and separated using α_2), thereby being reflected from the fast input port 121 to the output port 132 via the diffracted beam 162 and from the corresponding insertion port 112 to the fast output port 123. Finally, as Figure 3J and 3KAs shown, N insertion ports 110 and N output ports 130 can form N insertion-output pairs 320, wherein the insertion ports 110 and the corresponding output ports 130 are arranged at the same angular distance Δθ relative to the fast input port 121 or the fast output port 132, such that one of the N switching elements (in state α_N) can simultaneously reflect the diffracted beam 160 from the fast input port 121 to the output port 130 and from the corresponding insertion port 110 to the fast output port 123.

[0059] Based on this disclosure, those skilled in the art will recognize that each insert-output pair 320 can use any number of switching elements 190 to simultaneously insert and output signals in any number of wavelength bands, each wavelength band containing any number of wavelength channels. Furthermore, because they are arranged symmetrically along the displacement axis relative to the fast input port 121 and the fast output port 123, each insert-output pair 320 can be used to simultaneously insert and output signals in one or more of the same wavelength bands. Therefore, to insert and output signals in a wavelength band, all signals to be inserted in the wavelength band can be provided to one of the insert ports 110 of the interlocked N×N WSS 300, which can then be used to output signals in the wavelength band to the corresponding output port 130.

[0060] By eliminating the need to use dual conventional 1×N WSS (e.g., as Figure 1A-1E As shown), the interlocked N×N WSS300 embodiment can achieve higher performance than conventional OADMs (e.g., as shown). Figure 2A-2H Provided in a simpler, more compact package (as shown). Meanwhile, the insertion loss and switching loss introduced by the interlocked N×N WSS 300 embodiment can be as low as a single 1×N WSS. Therefore, compared to a conventional OADM using dual conventional 1×N WSSs, the N×N WSS 300 embodiment can reduce connection and switching losses by approximately 50% (e.g., reduce insertion loss along the fast path by approximately 6 dB). As a result, the interlocked N×N WSS 300 embodiment can reduce the number of amplifiers required to amplify unintentionally attenuated signals, the material cost of manufacturing these amplifiers, and the electrical power consumed by these amplifiers and the pumps providing said amplification.

[0061] As described above, arranging each insert port 110 and output port 130 of each insert-output pair 320 also enables the interlocked N×N WSS 300 embodiment to simultaneously reflect signals to both ports using the passive optical system 180, eliminating the need for active components (such as the N-element MEMS switch array used in a conventional M×N WSS module) between the optical array 120 and the switching element 190. Therefore, the interlocked N×N WSS 300 embodiment is simpler and less expensive than a conventional M×N WSS module, while introducing less insertion loss (e.g., as low as a single 1×N WSS).

[0062] As described above, the passive optical system 180 may include any number of optical elements capable of appropriately diffracting the optical signal from the optical input array 310 and providing the optical signal to the optical output array 330 via the switching element 190. (Refer to above) Figure 1A As described, for example, the passive optical system 180 may optionally include a collimating optics 140, one or more dispersive elements 150, and a focusing optics 170. Additionally, the passive optical system 180 may include, for example, polarization diversity optics, compensation optics, one or more mirrors, etc.

[0063] In some embodiments, the optical array 120 and the switching element array 190 can be aligned along the emission axis ( Figure 1A Alignment with the 'z' axis (e.g., as shown in the image) Figure 1A As shown). In those embodiments, the dispersive element 150 can be along the displacement axis (as shown). Figure 1A-1E (y-axis) and emission axis ( Figure 1A-1E The diffraction axes (in the z-axis) are both orthogonal to each other. Figure 1A-1E Each collimated light signal 141 is diffracted (arbitrarily labeled as the 'x' axis). However, in other embodiments, the optical array 120 and the switching element array 190 may not be aligned along the emission axis, and the passive optical system 180 may include one or more passive reflective elements that reflect, refract, diffract, or otherwise guide the light signal between the optical array 120 and the switching element array 190.

[0064] exist Figure 3A-3K In the example embodiment shown, the ports of the optical array 120 are substantially along the displacement axis (e.g., Figure 3B-3EAlignment is performed with the reflected light signal along the displacement axis (e.g., the 'y' axis), and the switching element 190 displaces the reflected light signal along the displacement axis before transmission through the passive optical system 180. However, as those skilled in the art will recognize based on this disclosure, the passive optical system 180 may contain any number of passive elements that reflect, refract, diffract, guide, or otherwise alter the trajectory of the light signal. Therefore, as used herein, displacing the reflected light signal along the displacement axis means reflecting those light signals so that they are displaced along the displacement axis at the optical array 120 (i.e., the reflection so that they are provided to the intended port after transmission through the passive optical system 180).

[0065] Because the switching element 190 reflects the signal bidirectionally, the terms "input" and "output" are used arbitrarily herein. Therefore, according to the embodiment, the optical input array 310 and the optical input array 310 can be used interchangeably. Similarly, depending on the embodiment, either of the two ports in each insert-output pair 320 can be used as either the insert port 110 or the output port 130, provided that the angular difference Δθ between the diffracted beams 161 received from the fast input port 121 and the output port 110 (via the passive optical system 180) is the same as the angular difference Δθ between the reflected beams output (via the passive optical system 180) to the fast output port 121 and the corresponding output port 130.

[0066] Each port optical array 120 can be implemented as any hardware element capable of appropriately outputting and / or receiving optical signals. For example, each port can be an optical fiber, an optical waveguide, etc. The interlocked N×N WSS 300 comprises N insertion-output pairs 320. In various embodiments, the number of insertion-output pairs N can be any integer greater than 0.

[0067] The switching element 190 can be implemented as any hardware element capable of appropriately reflecting the optical signal as described above. For example, an array of switching elements 190 can be implemented as a liquid crystal on silicon (LCoS) switching engine—a solid-state display engine that forms an electrically programmable grating by controlling the phase of light at each pixel. In those embodiments, each switching element 190 can be implemented as part of a display area, which can be placed in state α by controlling the grating formed in said part of the display area. In another example, the array of switching elements 190 can be a MEMS switching engine. In those embodiments, each switching element 190 can be implemented as a micromirror tilted due to electrostatic attraction, which can be placed in state α by applying a voltage to an electrode. In another example, the array of switching elements 190 can be implemented as a liquid crystal (LC) switching engine, wherein each switching element 190 is implemented as a liquid crystal cell that selectively controls the polarization state of transmitted light according to the applied voltage. In those embodiments, the array of switching elements 190 (or passive optical system 180) may also include polarization-dependent optical elements (e.g., polarization beam splitters) that alter the path of transmitted light based on polarization, and each switching element 190 can be placed in state α by applying a voltage associated with state α. In another example, the array of switching elements 190 may be implemented as an optical switching engine with liquid crystal and birefringent optical wedges, as described, for example, in U.S. Patent No. 7,492,986.

[0068] The interlocked N×N WSS 300 may include a controller that controls the state α of each switching element 190 to selectively pass signals from the fast input port 121 to the fast output port 123 (e.g., as shown in the image). Figure 3B (as shown), or simultaneously insert a signal from one of the insertion ports 130 and branch the signal to the corresponding output port 130 (e.g., as shown). Figure 3C-3K (As shown). The controller may contain any hardware element (e.g., hardware processor, state machine, etc.) capable of properly controlling each switching element 190.

[0069] While preferred embodiments have been described above, it will be readily apparent to those skilled in the art upon reading this disclosure that other embodiments may be implemented within the scope of this invention. Therefore, this invention should be construed as being limited only by any of the appended claims.

Claims

1. An interlocked N×N wavelength selective switch (WSS), comprising: An optical input array configured to receive an input optical signal, the optical input array including a fast input port and N insertion ports; An optical output array, the optical output array including a fast output port and N output ports, the N output ports and the N insertion ports forming N insertion-output pairs, each of the N insertion-output pairs including an insertion port among the N insertion ports and a corresponding output port among the N output ports; Switching element array; as well as A passive optical system configured to diffract the input optical signal to form a diffracted optical signal, focus the diffracted optical signal onto the switching element array, receive a reflected optical signal from the switching element array, and focus the reflected optical signal onto the optical output array. The insertion port and the corresponding output port of each insertion-output pair are arranged relative to the fast input port and the fast output port, such that the input optical signal can be simultaneously reflected from the insertion port to the fast output port and from the fast input port to the corresponding output port by one of the switching elements through the passive optical system.

2. The WSS according to claim 1, wherein: The fast input port, the N insertion ports, the fast output port, and the N branch ports are substantially aligned along the displacement axis; The optical input array emits the input optical signal along an emission axis orthogonal to the displacement axis; and The switching element is configured to reflect the diffracted light signal and to displace the reflected light signal along the displacement axis.

3. The WSS of claim 2, wherein the insertion port and the corresponding output port of each of the N insertion-output pairs are arranged along the displacement axis such that the angular difference between the diffracted beams output by the passive optical system from the fast input port and the insertion port is equal to the angular difference between the reflected beams output by the passive optical system to the fast input port and the corresponding output port and reflected by any of the switching elements of the switching elements.

4. The WSS of claim 1, wherein each switching element is configured such that: In state 0, the switching element is configured to reflect the diffracted light signal received from the fast input port via the passive optical system back to the fast output port through the passive optical system; and In at least one other state, the switching element is configured to simultaneously: The diffracted light signal received through the passive optical system is reflected from the insertion port of one of the N insertion-exit pairs to the fast output port through the passive optical system; and The diffracted light signal received through the passive optical system is reflected from the fast input port to the corresponding output port of the insert-output pair through the passive optical system.

5. The WSS of claim 4, wherein the at least one additional state comprises N additional states, each of the N additional states corresponding to one of the N insert-drop pairs, wherein the switching element is configured to simultaneously: The diffracted light signal received through the passive optical system is reflected from the insertion port of the corresponding insertion-exit pair to the fast output port through the passive optical system; and The diffracted light signal received through the passive optical system is reflected from the fast input port to the output port of the corresponding insert-output pair through the passive optical system.

6. The WSS according to claim 5, further comprising: A controller configured to selectively transmit a signal from the fast input port to the fast output port, or simultaneously insert and output a signal, by changing the state of one or more of the switching elements.

7. The WSS according to claim 6, wherein: The passive optical system includes a dispersive element that divides the input optical signal into diffracted optical signals in multiple wavelength bands. Each switching element receives and reflects the diffracted optical signal from one of the plurality of wavelength bands; and The controller is configured to selectively transmit, insert, and extract signals in each wavelength band by controlling the state of the switching element that receives the diffracted optical signal in each wavelength band.

8. The WSS of claim 1, wherein the WSS is configured to: The signal in the wavelength band received by the insertion port of one of the N insertion pairs; and The signal in the wavelength band received through the fast input port is separated by outputting the separated signal through the corresponding output port of the insert-output pair.

9. The WSS of claim 8, wherein the signal in the wavelength band received through both the insertion port and the fast input port is diffracted to a switching element in the switching element array and simultaneously reflected by the switching element.

10. The WSS according to claim 1, wherein the switching element array comprises a liquid crystal on silicon (LCoS) switching engine, a microelectromechanical system (MEMS) switching engine, a liquid crystal (LC) switching engine, or an optical switching engine having liquid crystal and a birefringent optical wedge.

11. A method for selectively transmitting or simultaneously inserting and separating optical signals according to wavelength, the method comprising: The input optical signal is received through an optical input array including a fast input port and N insertion ports; An optical output array is provided, the optical output array including a fast output port and N output ports, the N output ports and the N insertion ports forming N insertion-output pairs, each of the N insertion-output pairs including an insertion port among the N insertion ports and a corresponding output port among the N output ports; The input optical signal is diffracted using a passive system to form a diffracted optical signal, and the diffracted optical signal is focused onto an array of switching elements. Control the array of switching elements to reflect the diffracted light signal and form a reflected light signal; as well as The passive optical system is used to focus the reflected light signal onto the light output array. The insertion port and the corresponding output port of each insertion-output pair are arranged relative to the fast input port and the fast output port, such that the input optical signal can be simultaneously reflected from the insertion port to the fast output port and from the fast input port to the corresponding output port by one of the switching elements through the passive optical system.

12. The method according to claim 11, wherein: The fast input port, the N insertion ports, the fast output port, and the N branch ports are substantially aligned along the displacement axis; and Reflecting the diffracted light signal includes displacing the reflected light signal along the displacement axis.

13. The method of claim 12, wherein the insertion port and the corresponding output port of each of the N insertion-output pairs are arranged along the displacement axis such that the angular difference between the diffracted beams output by the passive optical system from the fast input port and the insertion port is equal to the angular difference between the reflected beams output by the passive optical system to the fast input port and the corresponding output port and reflected by any of the switching elements of the switching elements.

14. The method of claim 11, further comprising: In state 0, one of the switching elements reflects the diffracted light signal received from the fast input port through the passive optical system back to the fast output port via the passive optical system; and When in at least one other state, the switching element simultaneously: The diffracted light signal received through the passive optical system is reflected from the insertion port of one of the N insertion-output pairs to the fast output port through the passive optical system. as well as The diffracted light signal received through the passive optical system is reflected from the fast input port to the corresponding output port of the insert-output pair through the passive optical system.

15. The method of claim 14, wherein each of the switching elements is controllable to be placed in the 0th state or one of the N other states, each of the N other states corresponding to one insertion-exit in the N insertion-exit pairs, the method comprising: When one of the N other states is in a certain state, one of the switching elements simultaneously: The diffracted light signal received through the passive optical system is reflected from the insertion port of the corresponding insertion-splitter pair to the fast output port through the passive optical system. as well as The diffracted light signal received through the passive optical system is reflected from the fast input port to the output port of the corresponding insert-output pair through the passive optical system.

16. The method of claim 14, further comprising: Signals can be selectively transmitted from the fast input port to the fast output port, or simultaneously inserted and output, by controlling the state of one or more of the switching elements.

17. The method of claim 14, further comprising: The passive optical system is used to divide the input optical signal into diffracted optical signals in multiple wavelength bands; The diffracted optical signal in each wavelength band is provided to one of the switching elements; as well as Signals are selectively transmitted, inserted, and separated according to wavelength bands by controlling the state of the switching element that receives the diffracted optical signal in each wavelength band.

18. The method of claim 11, further comprising: The signal in the wavelength band received by the insertion port of one of the N insertion pairs is inserted; as well as The signal in the wavelength band received through the fast input port is separated by outputting the separated signal through the corresponding output port of the insert-output pair.

19. The method of claim 18, further comprising: The passive optical system is used to diffract the signal in the wavelength band received through the insertion port and the fast input port to a switching element in the switching element array; as well as The diffracted beam in the wavelength band is simultaneously reflected by the switching element.

20. A method for manufacturing an interlocked N×N wavelength selective switch (WSS), the method comprising: Form an optical input array including a fast input port and N insertion ports; An optical output array is formed, the optical output array including a fast output port and N output ports, the N output ports and the N insertion ports form N insertion-output pairs, and each of the N insertion-output pairs includes an insertion port among the N insertion ports and a corresponding output port among the N output ports; Provides an array of switching elements; as well as A passive optical system is arranged to diffract the input optical signal to form a diffracted optical signal, focus the diffracted optical signal onto the switching element array, receive a reflected optical signal from the switching element array, and focus the reflected optical signal onto the optical output array. The formation of the optical input array and the formation of the optical output array include arranging each insert port and corresponding output port of each insert-output pair relative to the fast input port and the fast output port, such that the input optical signal can be simultaneously reflected from the insert port to the fast output port and from the fast input port to the corresponding output port by one of the switching elements through the passive optical system.

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