Non-intrusive real-time monitoring system for MXN optical circuit switch with MEMS mirror array based switching engine

Abstract

A system and method for monitoring an optical path switching device is provided. The system can include a first light source generating a first reference light beam; a first optical device transmitting light and reflecting light; a first optical filter positioned between an input collimator array and a lens structure; the first optical filter receiving the first reference light beam from the first optical device and passing the first reference light beam through a first set of MEMS arrays and a second set of MEMS arrays; a first monitoring device receiving the first reference light beam, the first reference light beam monitoring at least a first mirror deflection in the first set of MEMS arrays; and a second monitoring device simultaneously receiving a second reference light beam, the second reference light beam monitoring at least a second mirror deflection in the second set of MEMS arrays.

Description

Technical Field

[0001] This disclosure relates to the field of optical networks, and more specifically, but not exclusively, to the field of optical path switches and monitoring systems based on microelectromechanical systems (MEMS) mirrors. Background Technology

[0002] Optical path switches (OCS), or photonic cross-connects (PXCs), are the core of optical path-switched networks. OCSs offer advantages over non-switched optical networks or those with optical-to-electrical-to-optical conversion.

[0003] MxN OCS is an optical path switch (OCS) that connects optical signals from any one of M input ports to any one of N output ports. Notably, MxN OCS devices are steadily replacing electrical packet switches in data center interconnects. This is likely due to the significant capacity increases and low power consumption driven by artificial intelligence (AI) networks.

[0004] In order to provide reliable network connectivity and switching services, monitoring systems are needed to detect performance degradation and failures during service.

[0005] Current solutions merely monitor changes in optical loss in the system using optical power tapping at each input and output port via photodiodes (PDs) and associated electronics. In response, switching engine operating parameters can be adjusted via a closed loop. However, current solutions are costly and resource-intensive due to the need for M+N sets of PDs and detection electronics. Furthermore, this introduces additional losses due to the two-stage tapping losses, further increasing the cost of the optical transceivers, as high-side transceivers are required to compensate for these additional tapping losses. Moreover, additional obstacles arise in other scenarios, such as dark switching. Without input port light, there is no signal on the PD monitor, and the MEMS mirror angle offset is unknown.

[0006] Therefore, there is a need for a system and method that can overcome the aforementioned shortcomings of known systems. Summary of the Invention

[0007] According to one embodiment, this disclosure relates to a monitoring system for an optical path switching device. The monitoring system includes: a first light source generating a first reference beam; a first optical device transmitting and reflecting light; a first filter located between an input collimator array and a lens structure; the first filter receiving the first reference beam from the first optical device and allowing the first reference beam to pass through a first MEMS array and a second MEMS array; a first monitoring device receiving the first reference beam, the first reference beam monitoring at least the offset of a first mirror in the first MEMS array; and a second monitoring device simultaneously receiving a second reference beam, the second reference beam monitoring at least the offset of a second mirror in the second MEMS array.

[0008] According to another embodiment, the monitoring system further includes: a second light source that generates a second reference beam; a second optical device that reflects and transmits light; and a second filter located between the output collimator array and the second lens structure; the second filter receives the second reference beam from the second optical device and allows the second reference beam to pass through a set of second MEMS arrays and a first MEMS array.

[0009] According to an embodiment, this disclosure relates to a method for monitoring an optical path switching device. The method includes the following steps: generating a first reference beam using a first light source; receiving the first reference beam from a first optical device that transmits and reflects light via a first filter located between an input collimator array and a lens structure; passing the first reference beam through a first MEMS array and a second MEMS array via the first filter; receiving the first reference beam via a first monitoring device, the first reference beam monitoring at least the offset of a first mirror in the first MEMS array; and simultaneously receiving a second reference beam via a second monitoring device, the second reference beam monitoring at least the offset of a second mirror in the second MEMS array.

[0010] According to one embodiment, this disclosure relates to a monitoring system for an optical path switching device. The monitoring system includes: a first collimator array having two or more input ports for receiving test beams from at least one test light source generating a test beam; a first MEMS array and a second MEMS array that receive the test beams from the two or more input ports and guide the received test beams to the second collimator array; a second collimator array including two or more output ports for receiving the test beams from the first MEMS array and the second MEMS array; and at least one test light detection device connected to the two or more output ports receiving the test beams, which monitors the optical path switching device.

[0011] According to an embodiment, this disclosure relates to a method for monitoring an optical path switching device. The method includes: generating a test beam from at least one test light source; receiving the test beam by a first collimator array having two or more input ports; passing the test beam through a first MEMS array and a second MEMS array via the two or more input ports; receiving the test beam through two or more output ports of a second collimator array; receiving the test beam by at least one test light detection device; and measuring the insertion loss of the optical path switching device using the test beam.

[0012] According to another embodiment, the method further includes the steps of: generating a second reference beam through a second light source; receiving the second reference beam from a second optical device that reflects and transmits light via a second filter located between an output collimator array and a second lens structure; and passing the second reference beam through a set of second MEMS arrays and a first MEMS array via the second filter.

[0013] These and other advantages will be described more fully in the following detailed description. Attached Figure Description

[0014] To facilitate a more complete understanding of this disclosure, reference is now made to the accompanying drawings. The drawings should not be construed as limiting the scope of this disclosure, but are merely intended to illustrate different aspects and embodiments of the disclosure.

[0015] Figure 1 This is an example diagram of a monitoring system for an optical path switch (OCS) according to an embodiment of the present disclosure.

[0016] Figure 2A This is an example diagram of a lens structure according to an embodiment of the present disclosure.

[0017] Figure 2B This is an example diagram of a monitoring system having a lens structure for an optical path switch (OCS) according to an embodiment of the present disclosure.

[0018] Figure 3A and Figure 3B The insertion loss according to an embodiment of the present disclosure is shown.

[0019] Figure 4A This is an example diagram of a lens structure according to an embodiment of the present disclosure.

[0020] Figure 4B An exemplary graph is shown, illustrating the relationship between the beam spot diameter and the focal length of the microlens on a camera according to an embodiment of this disclosure.

[0021] Figure 5A and Figure 5B The relative light intensities according to embodiments of this disclosure are shown.

[0022] Figure 6A and Figure 6B This is an exemplary flowchart for calibration and control according to embodiments of the present disclosure.

[0023] Figure 7 This is an exemplary flowchart for determining the insertion loss of an OCS and its variation according to embodiments of the present disclosure. Detailed Implementation

[0024] The specific embodiments described below with reference to the accompanying drawings are intended as descriptions of various configurations, and not as representations of only configurations in which the concepts described herein can be practiced. The specific embodiments include detailed descriptions intended to provide a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form to avoid obscuring these concepts.

[0025] One or more embodiments relate to an optical switching device including an optical path switch (OCS) and one or more lenses configured within the optical switching device for focusing input and output signals. The lenses may represent field lenses or focusing lenses, which can reduce the beam divergence angle and extend the Rayleigh length or range. Field lenses or focusing lenses can effectively reduce beam diffraction losses. The optical switching device may include collimator arrays, microelectromechanical systems (MEMS), micromirror arrays (MEMS arrays), and lenses coupled to the collimators that focus the signals onto the MEMS array. In this disclosure, micromirrors or mirrors are used interchangeably. According to one or more embodiments, the collimator may include an optical fiber array for receiving or transmitting optical signals at the optical switching device. The optical lens array may be aligned with and optically coupled to the optical fiber array.

[0026] One embodiment relates to a non-invasive real-time monitoring system that avoids the need for optical power tapping. According to one embodiment, the monitoring system can be implemented to support non-signal band wavelength light as a reference beam and then monitor its optical system, which is coupled to a monitoring device (e.g., a camera). According to the exemplary description, the monitoring system can be used with an OCS having a switching engine based on a MEMS mirror array, as described in detail in U.S. Patent No. 11,506,884, the entire contents of which are incorporated herein by reference. Other implementations and / or integration with a variety of other optical devices can be supported.

[0027] Figure 1This is an example diagram of a monitoring system for an optical path switch (OCS) according to one or more embodiments. The OCS100 may be an all-optical switching matrix including: an input collimator shown by a collimator array 110 having m collimator elements; a MEMS array 130 including m micromirror elements; a MEMS array 140 including n micromirror elements; and an output collimator shown by a collimator array 150 having n collimator elements. For example, the collimator can narrow or align the beam for output through the collimator.

[0028] The input collimator may include multiple collimators, which may be coupled to m optical fibers. Each optical fiber is coupled to a port of the input collimator. Input optical signals can enter the ports of the input collimator through the optical fibers for transmission through the device OCS 100. The signal transmitted through each optical fiber may include one or more optical wavelengths (λi). Output light from the output collimator (collimator array 150) (e.g., from collimator 110 via paths 132A, 132B, 132n to collimator 150) can be provided to a set of output optical fibers through multiple output ports, each output port carrying a signal of one or more optical wavelengths (λi).

[0029] In one or more embodiments, collimator arrays 110 and 150 include multiple input ports and / or output ports. For example, in a non-limiting example, the collimator array (e.g., collimator array 110) may include 560 ports. Typically, only a certain percentage of the ports are needed, such as 512 ports; the remaining ports are either non-operating spare ports or can be used to determine insertion loss and its variation.

[0030] A test light source (e.g., a coherent light source with the same wavelength as the signal) can be coupled to an input port of the input collimator array 110. The test light is then received by an additional port of the output collimator array 150 and passed to a photodetector (e.g., but not limited to a photodetector, camera, or other intensity detector) to determine the level of insertion loss by comparing the power of the test light source with the power of the received light. While some insertion loss is expected, if the detected level of insertion loss variation exceeds a predetermined threshold, this could be an indication that MEMS arrays 130 and 140 may require calibration or that there are other problems in the OCS 100.

[0031] For example, in a non-limiting example, if the input collimator array 110 and the output collimator array 150 each have 700 ports, then 140 ports may be defective due to various reasons related to the assembly and fabrication of the collimator arrays 110, 150 or the MEMS arrays 130, 140; this results in 560 usable ports. If the OCS 100 only requires 544 ports to function, then in one or more embodiments, there will be 16 additional ports available to determine the insertion loss of the OCS and its variation. In one or more embodiments, these 16 additional ports may be divided into two groups, resulting in measurements at 8 plus 8 positions in both directions (from collimator arrays 110 to 150, and vice versa).

[0032] The collimator elements or ports of collimator arrays 110 and 150 can be independent single collimators or combined into collimator arrays. For example, input collimator 110 and output collimator 150 can be structurally similar. MEMS arrays 130 and 140 can represent MEMS-based micromirror arrays that can selectively guide light beams from individual fibers coupled to the input collimator (collimator array 110) to selected fibers coupled to the output collimator (collimator array 150). MEMS arrays 130 and 140 can include two sets of micromirror arrays, each having m and n micromirrors formed on a substrate. The micromirror arrays and their constituent elements can be referred to as opposing, facing, or adjacent elements. The substrate can serve as the base for the micromirror elements.

[0033] The state of each micromirror can be controlled by applying a voltage between two or more electrodes associated with each micromirror in the MEMS arrays 130 and 140. For example, by rotating the micromirrors in the MEMS arrays 130 and 140, a signal from any input fiber coupled to the input collimator (collimator array 110) can be transmitted to any output fiber coupled to the output collimator (collimator array 150). In some embodiments, the voltage may have a maximum value or may be limited such that the micromirror has a maximum tilt angle or scanning range. Those skilled in the art will recognize that the control of the micromirrors can be influenced by other mechanisms and forms of excitation, including, for example, mechanical, electromagnetic, and / or chemical processes.

[0034] Those skilled in the art will readily recognize that other configurations of the OCS device or system are also possible. Any combination of various collimator and micromirror arrangements is possible, including scaled collimator spacing, circular, hexagonal, and / or other micromirror arrangements based on user and other needs or preferences.

[0035] like Figure 1As shown, according to one or more embodiments, OCS 100 may include two lenses 122, 124 for focusing beams input to and output from MEMS arrays 130, 140. OCS 100 may represent an all-optical switching matrix including an input collimator, a collimator array 110 including m collimator elements or ports, MEMS array 130, and MEMS array 140, which can be controlled to pass beams from any input collimator element of collimator array 110 to any output collimator element of collimator array 150.

[0036] OCS 100 may include a lens element (shown as lens 122) that has a focal point at the MEMS array 140. For example, lens 122 may have a focal point at the center or near the center of the MEMS array 140. OCS 100 may also include a lens element (shown as lens 124) that has a focal point at the MEMS array 130. For example, lens 124 may have a focal point at the center or near the center of the MEMS array 130. Figure 1 In the example, lens 124 can be configured to allow the light beam to pass through such that the light beam is perpendicular (or parallel) to the direction of the input of each respective collimator element or port of collimator array 150.

[0037] The input collimator (collimator array 110) may include multiple collimators, which may be coupled to m optical fibers. The input optical signal transmitted through each optical fiber may include one or more optical wavelengths (λi). The output light from the output collimator (collimator array 150), which includes collimator elements, may be provided to a set of output optical fibers, each carrying a signal of one or more optical wavelengths (λi). Paths 132A, 132B, and 132n may represent light or beam paths. Paths 132A, 132B, and 132n may be collimated beams from collimator array 110 through lens 122, which focuses the beam toward the center or approximately the center of MEMS array 140.

[0038] Collimators can be individual collimators or collimator arrays. According to one or more embodiments, the input and output collimators (collimator array 110 and collimator array 150) can be structurally similar. The MEMS array 130 can represent a MEMS-based micromirror array that can selectively guide light beams from individual fibers coupled to the input collimator (collimator array 110) through lenses 122, 124 to selected fibers coupled to the output collimator (collimator array 150).

[0039] MEMS arrays 130 and 140 may include multiple arrays of micromirrors. The state of each micromirror can be biased by applying a voltage or charge between two or more electrodes associated with each micromirror in the MEMS arrays 130 and 140. In the unbiased state, no voltage can be applied to the micromirrors. In the biased state, for example, by applying a voltage and rotating the micromirrors in the MEMS arrays 130 and 140, a signal from any input fiber coupled to the input collimator (collimator array 110) can be directed to any output fiber coupled to the output collimator (collimator array 150).

[0040] exist Figure 1 In the example, the micromirrors can be in an unbiased state (e.g., without applied voltage or charge), such that beam paths 132A, 132B, 132n are focused toward or approximately toward the center of the MEMS array 140. Using lens 122, the beam can be guided to the entire MEMS array 140 (e.g., any micromirrors), thereby biasing the micromirrors across the entire scanning range.

[0041] Lenses 122 and 124 can be structurally similar and can comprise matching lens groups with similar characteristics. For example, lenses 122 and 124 can have the same or substantially similar focal lengths. The OCS 100 can be designed symmetrically, with corresponding input and output elements having similar structures. For example, MEMS arrays 130 and 140 can be located at similar distances and offset angles from lenses 122 and 124, respectively. The design and operation of the OCS 100 can be simplified when its components share common properties. For example, the control of MEMS arrays 130 and 140 can be similar, with each array sharing common control logic.

[0042] According to one or more embodiments, the collimator elements of one or both of the collimator arrays 110, 150 may have regular or scaled spacing. In another embodiment, the elements of one or both of the MEMS arrays 130, 140 may be arranged in a pattern, such as a circular pattern, a hexagonal pattern, etc. For example, when the collimator arrays 110, 150 have scaled spacing and / or the MEMS arrays 130, 140 have a circular / hexagonal pattern, the OCS 100 can be designed in a smaller package. In some embodiments, when the collimator arrays 110, 150 have scaled spacing and / or the MEMS arrays 130, 140 have a circular / hexagonal pattern, the OCS 100 can be designed to have a greater number of micromirror elements m and n than when it does not have any of the spacing and circular / hexagonal patterns. Using lenses 122, 124, an OCS specifying a given maximum micromirror voltage can be designed to have a larger number of ports. Furthermore, for the same number of input / output ports, OCS can be designed in a smaller physical package.

[0043] Although lenses 122 and 124 are illustrated as positive powered lenses (convex lenses), those skilled in the art will readily recognize that lenses can take various forms, including prisms, negative powered lenses (concave lenses), etc. Furthermore, other embodiments may employ passive and / or active elements.

[0044] Several aspects of optical switching systems will now be described with reference to various devices and methods. These devices and methods will be described in detail below and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively, "elements"). These elements can be implemented using electronic hardware, computer software, or any combination thereof. Whether these elements are implemented as hardware or software depends on the specific application and the design constraints on the overall system.

[0045] According to one or more embodiments, the OCS 100 may include a collimator array 110 that outputs optical signal light through a lens 122. The focused light can then be received by MEMS arrays 130 and 140, and its output is received by a lens 124 and transmitted to a collimator array 150.

[0046] Collimator array 110 and collimator array 150 can output each optical signal light from any port of the input port as a collimated beam and couple any incident beam to a specific output fiber of the output port.

[0047] Lens 122 can represent an achromatic field lens, which focuses the incident signal beam onto the center of the second MEMS array 140. The achromatic field lens 122 can relay the waist of the incident signal beam to a position located between MEMS arrays 130 and 140. Based on the focusing of the incident signal beam, the achromatic field lens 122 can magnify the spacing of the MEMS mirror array relative to the collimator array 110, thereby magnifying the collimator array spacing and allowing adjustment of each collimator in the collimator array 110 as needed. By magnifying the spacing, one or more embodiments facilitate and improve the manufacturing of the collimator. This contrasts with current solutions, where both the MEMS mirror array spacing and the collimator array spacing are small, leading to complex manufacturing processes.

[0048] Each mirror in MEMS array 130 can deflect the incident signal beam to any one of the mirrors in MEMS array 140. Each mirror in MEMS array 140 can deflect the incident beam to any one of the output collimator arrays in collimator array 150.

[0049] One or more embodiments relate to a monitoring system for an OCS device 100. The monitoring system may include wavelength division multiplexing (WDM) filters, optical devices (e.g., beam splitters, polarization beam splitters (PBS), filters), collimating reference light sources, and cameras (or other monitoring devices).

[0050] like Figure 1 As shown, WDM filter 120 can be located between the input collimator (shown as collimator array 110) and lens 122. WDM filter 126 can be located between lens 124 and output collimator (shown as collimator array 150).

[0051] WDM filters 120 and 126 can combine or separate a signal band beam from a monitoring reference beam using a wavelength outside the signal band. For example, the wavelength of the monitoring reference beam can be 800 nm-900 nm, while the signal band can be in the O, C, L, or E bands. Other signal bands that do not conflict with the monitoring reference beam band can be supported.

[0052] WDM filters 120 and 126 can be transparent to all signal bands and include a highly reflective element for monitoring a reference wavelength. It is noteworthy that a WDM filter is not required between the two MEMS arrays (e.g., MEMS array 130 and MEMS array 140 shown). One or more embodiments may use only two WDM filters. According to one or more embodiments, WDM filters 120 and 126 are configured outside MEMS arrays 130 and 140 (e.g., in the optical path of light propagating between MEMS arrays 130 and 140). Furthermore, one or more embodiments may omit the reflector outside MEMS arrays 130 and 140.

[0053] One or more embodiments monitor a first single collimated beam from a first end to a second end, while simultaneously monitoring a second single collimated beam from the second end to the first end. A WDM filter combines the signal path and reference beam in the OCS device. In one or more embodiments, the reference beam is combined with the signal beam from the input collimator, transmitted through the MEMS array, and then separated for reception by a monitoring device (such as a camera), while the signal beam passes through the output collimator. One or more embodiments use the reference beam to detect and monitor the combined effects of the stability of the optical system passing through the signal beam and the offset of the MEMS mirrors in the signal beam path.

[0054] Optical devices 168 and 178 can represent beam splitters, such as 50 / 50 beam splitters (or other power splitting ratios), which multiplex / demultiplex two monitoring reference beams having any polarization state. In this example, optical devices 168 and 178 both allow the first reference beam to pass through while reflecting the second reference beam with a power attenuation according to its splitting ratio (e.g., 3 dB if it is 50 / 50).

[0055] Optical devices 168 and 178 can also represent a PBS for multiplexing / demultiplexing two monitoring reference beams with polarization directions perpendicular to each other. In this example, optical devices 168 and 178 both allow a first reference beam with one polarization (p) to pass through while reflecting a second reference beam with orthogonal polarization (s).

[0056] Optical devices 168 and 178 can also represent filters, such as coarse wavelength division multiplexing (CWDM) filters. In this example, optical devices 168 and 178 each allow a first reference light of one wavelength to pass through while reflecting a second reference light of another wavelength. Optical devices 168 and 178 can also represent other optical devices, such as couplers, circulators, etc.

[0057] like Figure 1As shown, the WDM filter 120 can receive a first reference beam 180 from the light source 162 via the optical device 168. The first reference beam 180 passes through the WDM filter 120 and the WDM filter 126, and is received and captured by the monitoring device 176 via the optical device 178.

[0058] The first reference beam 180 can monitor the combination of mirror offsets in the first MEMS array 130 and the second MEMS array 140, and has a much higher monitoring sensitivity for mirror offsets in the first MEMS array 130. The first reference beam 180 propagates in the upstream direction.

[0059] In a similar manner, WDM filter 126 can receive a second reference beam 182 from light source 172 via optical device 178, as shown by the dashed line. The second reference beam 182 passes through WDM filter 126 and WDM filter 120, and is received and captured by monitoring device 166 via optical device 168.

[0060] The second reference beam 182 can monitor the combination of mirror offsets in the second MEMS array 140 and the mirror offsets in the first MEMS array 130, and has a much higher monitoring sensitivity for mirror offsets in the second MEMS array 140. The second reference beam 182 propagates in a downstream direction.

[0061] The collimated reference light source shown by light sources 162 and 172, as well as any test light source included in the first insertion loss monitor 184 and the second insertion loss monitor 186, may each include an LED (light-emitting diode), a laser (e.g., a VCSEL (vertical-cavity surface-emitting laser)), an FP (Fabry-Perot laser), a DFB (distributed feedback laser), or other light-generating components.

[0062] The collimating reference light source may include a lens or a set of lenses 160, 170 to collimate the laser into the OCS system and illuminate the entire MEMS array 130 or MEMS array 140. The lens design may be determined by the numerical aperture (NA) of the laser beam and the system field of view (FOV) size. One or more embodiments recognize that the larger the number of ports of the OCS, the larger the FOV size. For example, a 700 x 700 OCS may have a field of view size of approximately 80 x 80 mm.

[0063] A collimated reference light source (shown as light source 162) transmits a reference beam and propagates upstream to reach a mirror in the MEMS array 130, and the corresponding movement can be monitored by a monitoring device 176. In a similar manner, a collimated reference light source (shown as light source 172) transmits a reference beam to reach a mirror in the MEMS array 140, and the corresponding movement can be monitored by a monitoring device 166.

[0064] The first insertion loss monitor 184 and the second insertion loss monitor 186 may include one or more collimating light sources and may include LEDs, lasers (e.g., VCSELs), FPs, DFBs, or other light-generating components. Test insertion loss monitors (e.g., 184 and 186) may include a single light source or as many light sources as the additional ports in the collimator array 110. In one or more embodiments, test insertion loss monitors (e.g., 184 and 186) may include three light sources, two of which are combined and coupled to the additional ports in the collimator array 110, while the third is a spare. Test insertion loss monitors (e.g., 184 and 186) may have the same wavelength, similar wavelengths, or wavelengths within the wavelength range of the signal light used during normal operation of the OCS 100.

[0065] Monitoring devices 166 and 176 may each include a lens or a set of lenses 164 and 174, and an optical sensor array. The optical sensor array may include a CCD (charge-coupled device), CMOS (complementary metal-oxide-semiconductor), or other types of sensors. The optical sensor array may be located at the image plane of the lens, allowing the monitoring device (e.g., a camera) to directly monitor one or more focused beams.

[0066] For example, monitoring device 176 can monitor the collimated reference beam 180 at each mirror of MEMS array 130. Tilting offsets of the MEMS mirrors from their nominal positions may result in focused beam spots at different locations (e.g., pixels) of the sensor of monitoring device 176. Simultaneously, monitoring device 166 can monitor the collimated reference beam 182 at each mirror of MEMS array 140. Tilting offsets of the MEMS mirrors from their nominal positions may result in focused beam spots at different locations (e.g., pixels) of the sensor of monitoring device 166. The monitoring by monitoring devices 166 and 176 may occur simultaneously, nearly simultaneously, sequentially, or at other intervals.

[0067] The insertion loss monitors (e.g., 184 and 186) may each include an array of optical sensors. The insertion loss monitors (e.g., 184 and 186) may include one or more photodiodes, CCDs (charge-coupled devices), CMOS (complementary metal-oxide-semiconductor) sensors, or another type of sensor. Alternatively, the first insertion loss monitor 184 may be simply a test light source, and the second insertion loss monitor 186 may be simply an array of optical sensors, or the first insertion loss monitor 184 may be simply an array of optical sensors, and the second insertion loss monitor 186 may be simply a test light source.

[0068] Test insertion loss monitors (e.g., 184 and 186) can receive test light generated by the corresponding test insertion loss monitors (e.g., 184 and 186) from one or more additional ports of the input collimator array 110 and / or the output collimator array 150. In operation, in conjunction with power measurements from the test insertion loss monitors (e.g., 184 and 186), the test insertion loss monitors (e.g., 184 and 186) can measure the insertion loss variation of the OCS 100; such insertion loss variation may occur due to problems associated with the first MEMS array 130 and the second MEMS array 140, the first collimator array 110 and the second collimator array 150, or any other component of the OCS 100. When the insertion loss variation exceeds a predetermined threshold set by the manufacturer or user, the mirrors initially forming the MEMS arrays 130 and 140 can be reset to a calibration setting, and tests can be performed using light sources 162 and 172 and monitoring devices 166 and 176 to recalibrate the MEMS arrays 130 or 140. If this still does not result in acceptable insertion loss, appropriate changes can be made to other components, or the user or manufacturer can be warned that the OCS 100 is not operating correctly.

[0069] With the input beam focused by a field lens (e.g., 122), the (positive and negative) steering angles of the MEMS mirrors are more fully utilized to support an additional number of ports. By implementing a field lens (e.g., 122), the OCS device is able to support a larger number of ports. One or more embodiments recognize that the number of ports depends on the tilt angle of the MEMS array. However, larger angles increase the complexity of designing the MEMS array. MEMS arrays typically have tilt angles between + / -a (e.g., + / -5) degrees. Current solutions are limited to 0 to +a (e.g., +5) at one end and -a (e.g., -5) to 0 at the other, thus they do not fully utilize the MEMS array. By using a field lens (e.g., 122), one or more embodiments are able to utilize the entire range of tilt capabilities from +a to -a (e.g., +5 to -5) degrees. This can support a much larger number of ports, for example, an increase of 4 times.

[0070] According to one or more embodiments, the monitoring device can monitor a collimated beam, where a high angular resolution of 1 / 1000 degree can be achieved. Each monitoring device or camera can monitor the tilt position of a combination of two MEMS arrays, with much higher monitoring sensitivity for MEMS arrays at the far end. A pixel region can represent an image of a specific combination of two pairs of reflectors from two MEMS arrays illuminated by a reference light, where the light intensity of the pixel region can be monitored by the monitoring device.

[0071] One or more embodiments of the monitoring system can be placed outside the field lenses (e.g., not between the field lenses). With this configuration, the beam is close to the telecentric lens and approximately perpendicular to the monitoring device, which provides better resolution and improved accuracy.

[0072] Each monitoring device 166, 176 can monitor two MEMS arrays 130, 140. Using the monitoring results, MEMS arrays 130, 140 can then be controlled by each monitoring device or any other component or controller using a control algorithm. With this monitoring configuration, the bottom monitoring device 166 is more sensitive to detecting movement on MEMS array 140, while the top monitoring device 176 is more sensitive to detecting movement on MEMS array 130. The results from each monitoring device 166, 176 can be combined and weighted accordingly, or the individual results from each monitoring device 166, 176 can be used to determine the offset. When one or both monitoring devices 166, 176 detect an offset, commands can be issued to control or adjust either or both MEMS arrays. For example, the bottom monitoring device 166 can issue commands to MEMS array 140, while the top monitoring device 176 can issue commands to MEMS array 130. MEMS arrays 130, 140 can be controlled, and their positions optimized. Even when there is no input port light, the monitoring device can still monitor the reference light, thereby enabling the monitoring and maintenance of the optimized angles tilt-Y and tilt-X of the two MEMS mirrors.

[0073] One or more embodiments relate to the overall monitoring of an OCS system, which differs from traditional standalone monitoring. For example, the monitoring system can monitor a combination of the input MEMS tilt angle and the output MEMS tilt angle. Input monitoring relies more heavily on the input MEMS array, such as 90% input MEMS and 10% output MEMS. Output monitoring relies more heavily on the output MEMS array, such as 90% output MEMS and 10% input MEMS. One or more embodiments aim to monitor the tilt angles of the input and output MEMS arrays, as well as the relative motion between the two MEMS arrays. For example, monitoring upstream beam spot shift (Yu) and downstream beam spot shift (Yd). Based on known system parameters (e.g., the gap between the MEMS arrays (z1), the gap between the field lens and the MEMS array (z2)), the MEMS mirror offset angles a1 and a2 can be determined. Figure 1 z1 represents the distance between MEMS arrays 130 and 140; z2 represents the gap between field lens 122 and MEMS array 130 and the gap between field lens 124 and MEMS array 140; a1 represents the mirror offset angle of MEMS array 130; a2 represents the mirror offset angle of MEMS array 140.

[0074] Yu = (z1 + z2) a1+z2 a2

[0075] Yd = (z1 + z2) a2+z2 a1

[0076] Figure 2A This is an example diagram of a lens structure according to one or more embodiments. The monitoring system may include an additional lens structure having an image relay lens 210 that focuses a light beam onto the monitoring device 220. The monitoring device 220 may include a lens 222 and a sensor array 224. The lens 222 may include a set of lenses or a lens array.

[0077] Figure 2B This is a schematic diagram of a monitoring system having a lens structure for an optical path switch (OCS) according to one or more embodiments. Figure 2B As shown, the OCS 200 includes relay lens structures shown as 210A and 210B. Monitoring device 220A includes lens 222A and sensor array 224A. Similarly, monitoring device 220B includes lens 222B and sensor array 224B.

[0078] like Figure 2BAs shown, optical devices 168 and 178 can represent beam splitters (e.g., PBS, 50 / 50 beam splitters) and filters (e.g., CWDM filters). According to the exemplary illustration, optical devices 168 and 178 can represent CWDM filters. In this example, the system can implement a 0.85 μm wavelength VCSEL (as light source 162) for the upstream optical path and a 0.9 μm wavelength VCSEL (as light source 172) for the downstream optical path. The CWDM filters (as optical devices 168 and 178) allow 0.85 μm wavelength light to pass through and reflect 0.9 μm wavelength light. Monitoring device 220B can detect 0.85 μm light, and monitoring device 220A can detect 0.9 μm light.

[0079] According to the exemplary description, optical devices 168 and 178 can represent a beam splitter (PBS). In this example, the system can implement a VCSEL with a P-polarization state (as light source 162) for the upstream optical path and a VCSEL with an S-polarization state (as light source 172) for the downstream optical path. The PBS (as optical devices 168 and 178) allows P-polarized light to pass through and reflects S-polarized light. Monitoring device 220B can detect P-polarized light, and monitoring device 220A can detect S-polarized light. According to another example, optical devices 168 and 178 can represent a beam splitter with a 50 / 50 or other power splitting ratio. In this example, the system can implement VCSELs as light sources 162 and 172, where the VCSEL beams for the upstream and downstream paths can pass through the beam splitter twice. In this case, only a portion (e.g., 25% if it's 50 / 50) of the reference beam power can reach each monitoring device. However, there are no restrictions on the specific polarization or wavelength of the light source. This is beneficial for reducing costs.

[0080] One or more embodiments recognize that systems with large FOV sizes may require additional resources to support monitoring devices, such as cameras with large FOVs. One or more embodiments involve implementing a set of relay lenses with an N:1 magnification ratio in an OCS system to reduce the FOV in each direction to 1 / N. This enables the use of smaller camera systems with smaller sensors without sacrificing performance.

[0081] For example, according to one or more embodiments, a 700 x 700 OCS can have a corresponding FOV size of 80 x 80 mm. By implementing a 4:1 relay lens system, the FOV size can be reduced to 20 x 20 mm.

[0082] Using an achromatic field lens system, the monitoring reference beam can be parallel to the principal axis of the incident (hitting) relay lens. Each beam image centered on the sensor plane can correspond to a specific portion of the first collimated reference beam (180) or a specific portion of the second collimated reference beam (182), which is obtained by paired mirrors of the two MEMS arrays to be monitored. This facilitates the ability to track the movement of the beam on the image plane when it is linear.

[0083] For example, paired mirrors of MEMS arrays 130 and 140 can determine an initial reference beam diameter of 800 μm. After integrating a 4:1 relay lens that can cover approximately 1500 pixels (e.g., pixel size 4.5 μm) of the sensor, the beam diameter can be 200 μm. The OCS controller can then determine the beam center at the sensor based on the beam intensity distribution measured by the sensor's pixels.

[0084] In traditional systems, the monitoring beam may be tilted at different angles for each different pair of MEMS mirrors, where the beam offset is non-linear, and a camera monitoring diffuser may also be required. Therefore, if a diffuser is used on the image plane, the system resolution will be limited by the diffuser.

[0085] Figure 3A and Figure 3B An exemplary graph representing the sensitivity performance of an illustrative system according to one or more embodiments.

[0086] Figure 3A The relationship between insertion loss (in dB) and tilt-x offset (in degrees), representing the tilt angle offset of the first MEMS mirror, is shown. Insertion loss can represent a portion of the beam that cannot be coupled to the output port. In the Y direction, the angular spacing between adjacent ports is approximately 0.39 degrees. In the X direction, the angular spacing between adjacent ports is approximately 0.5 degrees.

[0087] Figure 3B The relationship between insertion loss (in dB) and tilt-x offset (in degrees) representing the tilt angle offset of the second MEMS array is shown.

[0088] For a 0.1 dB change in insertion loss, the first MEMS array mirror is allowed a tilt angle offset of approximately 0.01 degrees, and the second MEMS array mirror is allowed a tilt angle offset of 0.04 degrees.

[0089] A monitoring device (e.g., a camera) can detect the offset of the reference beam image center at a one-pixel (4.5 μm) offset. Therefore, one or more embodiments can support an angular sensitivity of 1 / 1000 degree.

[0090] Exemplary sensors may include CMOS sensors. For example, a CMOS sensor may have an effective area of ​​23.04 mm x 18.432 mm and an image size of 20 mm x 18.25 mm. This is merely an example for illustrative purposes. One or more embodiments may utilize other sensors, including other CMOS sensors.

[0091] Figure 4A This is an example diagram of a lens structure according to one or more embodiments. The monitoring system may include an additional lens structure having an image relay lens 410 that focuses a light beam onto the monitoring device 420. The monitoring device 420 may include a lens 422 and a sensor array 424. The lens 422 may include a set of lenses or a lens array.

[0092] One or more embodiments relate to a microlens array 430 for increasing the image sensitivity of a monitor. The microlens array 430 can be added before the sensor shown by the sensor array 424 in the monitoring device 420. Figure 2B As shown, the microlens array 430 can be integrated into the monitoring devices 220A and 220B of the OCS 200.

[0093] By adding a microlens array 430 between the camera lens (shown as lens 422) and the sensor (shown as sensor array 424), one or more embodiments can further reduce the beam size on the sensor. This configuration increases beam intensity to facilitate the controller's ability to identify the beam center and further improves the sensitivity and reliability of the monitoring system.

[0094] For example, the microlens array 430 can be designed to match the main ray of the beam shaped by the mirrors of the MEMS array 130 and MEMS array 140.

[0095] According to the exemplary description, without a microlens array, the beam spot diameter on the camera sensor can be expressed as 200 μm. Using the microlens array 430, the beam spot diameter can be reduced, and the beam intensity can be increased. For example, the focal length of the lens array can be designed to be between 1 mm and 10 mm. Therefore, computation time can be further reduced using a smaller number of pixels.

[0096] Figure 4B An exemplary graph according to one or more embodiments is shown, illustrating the relationship between the beam spot diameter on a camera and the focal length of a microlens. Figure 4B As shown, the beam spot diameter (in µm) on the camera is compared with the focal length (in mm) of the microlens. Figure 4BThe corresponding beam diameter on the camera sensor is shown. To reduce the beam diameter and improve sensitivity, microlenses with shorter focal lengths can be used.

[0097] Figure 5A and Figure 5B An exemplary graph illustrating image sensitivity according to one or more embodiments. One or more embodiments aim to increase image sensitivity by adding a microlens array (e.g., 430) before the sensor, as described above. Figure 4A As shown.

[0098] Figure 5A The relationship between relative light intensity and beam diameter on the camera is shown. Figure 5A The relative intensity (in dB) and the beam spot diameter on the camera (in mm) were compared. Point A represents zero relative intensity and the corresponding beam spot diameter of 0.2 mm. Point B represents 12 dB relative intensity and the corresponding beam spot diameter of 0.05 mm. Point C represents 24 dB relative intensity and the corresponding beam spot diameter of 0.01 mm.

[0099] Figure 5B The relationship between the illuminated camera pixels and the diameter of the light beam on the camera is shown. Figure 5B The number of illuminated pixels and the beam spot diameter (in mm) on the camera were compared. Point A represents approximately 1500 illuminated pixels and a corresponding beam spot diameter of 0.2 mm. Point B represents approximately 89 illuminated pixels and a corresponding beam spot diameter of 50 μm. Point C represents approximately 3 illuminated pixels and a corresponding beam spot diameter of 10 μm.

[0100] By adding a microlens array (e.g., 430) between the camera lens and the sensor, one or more embodiments can further reduce the beam size on the sensor, thereby increasing the beam intensity and making it easier for the controller to identify the beam center. Therefore, this configuration improves the sensitivity and reliability of the monitoring system.

[0101] Without a microlens array, the beam diameter on the camera can be 200 μm, illuminating approximately 1500 pixels (where the pixel size is expressed as 4.5 μm).

[0102] In one or more embodiments with a microlens array, the focal length is 10 mm, and the beam spot diameter on the camera can be expressed as approximately 50 μm, with the beam illuminating approximately 89 pixels. The relative signal strength can be increased to 12 dB.

[0103] In one or more embodiments with a microlens array, the focal length is 1 mm, and the beam spot diameter on the camera can be expressed as approximately 10 μm, where the beam illuminates approximately 3 pixels. The relative signal strength can be increased to 24 dB.

[0104] Figure 6A and Figure 6B This is an exemplary flowchart for calibration and control according to one or more embodiments. One or more embodiments relate to monitoring system calibration and control algorithms and systems.

[0105] For any pair of input-to-output port connections, a specific pair of mirrors on MEMS arrays 130 and 140 can be calibrated to optimize the mirror tilt angle by mapping the reference light focused beam spot to the nominal sensor positions on monitoring devices 176 and 166. These positions are then stored in the memory of the control unit.

[0106] exist Figure 6A Step 610 identifies a pair of input and output port combinations. Step 612 calibrates a pair of mirrors on a set of MEMS arrays. Step 614 identifies the mirror tilt angle corresponding to the reference beam spot for each pair of mirrors on the MEMS array. Step 616 identifies and stores the corresponding sensor position in memory.

[0107] During operation, if the control unit detects that the beam spot has shifted from its nominal position on the monitoring device 176, the control unit can automatically adjust the tilt angle of the mirror on the MEMS array 130 to bring it back in a closed-loop control manner.

[0108] Similarly, during operation, if the control unit detects that the beam spot has shifted from its nominal position on the monitoring device 166, the control unit can automatically adjust the tilt angle of the mirrors on the MEMS array 140 to restore it in a closed-loop control manner.

[0109] exist Figure 6B In step 620, the OCS device or system can be started. In step 622, the beam spot can be detected and identified by a corresponding monitoring device (e.g., a camera). In step 624, the nominal position of each monitoring device can be identified from memory or otherwise retrieved. In step 626, one or more embodiments can determine whether the beam spot has shifted from the identified nominal position or become misaligned. If not, the system can continue monitoring the beam spot in step 622. If yes, then in step 628, the system can automatically adjust the tilt angle of the mirrors in the MEMS array until alignment is achieved.

[0110] Figure 7 This is an exemplary flowchart for determining an insertion loss variation of an OCS according to one or more embodiments. One or more embodiments relate to an OCS 100, which includes a system for determining the insertion loss variation and performing actions to correct it.

[0111] exist Figure 7 Step 710 can initiate the operation of the OCS device or system. In step 720, at least one test light source is activated, generating test beams. These test beams are received by a first collimator array having two or more input ports. In one or more embodiments, a coupler can combine light from more than one test light source and couple it to two or more input ports. The test beams are transmitted from the collimator array to a first MEMS array and a second MEMS array, which guide the received test beams, along with any modulated beams used for normal OCS operation, to the second collimator array.

[0112] In step 730, a test beam is received from the second collimator array and directed to at least one test beam detection device connected to or coupled to two or more output ports of the second collimator array. In step 740, the insertion loss variation is determined for the OCS device.

[0113] In step 750, the insertion loss variation is compared to a predetermined threshold. This predetermined threshold can be a percentage or measurement of any insertion loss variation that is determined by the user or manufacturer and sufficient to warrant corrective action. Generally, a certain degree of insertion loss variation is acceptable due to the tolerances of various components of the OCS.

[0114] If, in step 750, it is determined that the insertion loss change is less than a predetermined threshold, the system continues to monitor the insertion loss change of the OCS in step 760 and repeats steps 730-370 until the OCS stops working (deactivated) or monitoring stops for any other reason. Steps 730-760 can be performed continuously or periodically. For example, if it is determined that the change typically occurs over a time period of several hours, it may be desirable to repeat steps 730-760 every half hour. Depending on user preferences, material tolerances, design considerations, and any other considerations, steps 730-760 can be performed more frequently or less frequently. Figure 7 The methods are not limited to the examples above.

[0115] However, if the insertion loss change exceeds a predetermined threshold in step 705, the MEMS array is placed in calibration mode in step 770. This recalibration can be performed as described above. Figure 6A and Figure 6B It can be accomplished as described in the text or by using any other useful method.

[0116] Once the MEMS array has been calibrated in step 770, the insertion loss change is determined again, and in step 780, it is determined whether the insertion loss change is still greater than a predetermined threshold. If it is still greater than the predetermined threshold, the user or other relevant parties can be notified in step 790. Alternatively, other corrective measures can be taken in step 790 to reduce the insertion loss below the predetermined threshold. Conversely, if it is determined in step 780 that the insertion loss is now less than the predetermined threshold, the method returns to step 760, where monitoring continues.

[0117] It should be understood that the specific order or hierarchy of steps in the disclosed process is an illustration of an exemplary method. It should be understood that the specific order or hierarchy of steps in the process can be rearranged based on design preferences. Furthermore, some steps can be combined or omitted. The appended method claims present the elements of each step in an illustrative order, but this does not imply limitation to the specific order or hierarchy presented.

[0118] The following provides an overview of the various aspects of this disclosure.

[0119] Aspect 1: A monitoring system for an optical path switching device, the monitoring system comprising: a first light source generating a first reference beam; a first optical device transmitting light and reflecting light; a first filter located between an input collimator array and a lens structure; the first filter receiving the first reference beam from the first optical device and allowing the first reference beam to pass through a first MEMS array and a second MEMS array; a first monitoring device receiving the first reference beam, the first reference beam monitoring at least the offset of a first mirror in the first MEMS array; and a second monitoring device simultaneously receiving a second reference beam, the second reference beam monitoring at least the offset of a second mirror in the second MEMS array.

[0120] Aspect 2: The monitoring system according to aspect 1, wherein the first light source includes a collimating reference light source.

[0121] Aspect 3: The monitoring system according to any one of Aspects 1 to 2, wherein the first optical device includes one of the following: PBS, beam splitter, WDM filter, coupler and circulator.

[0122] Aspect 4: A monitoring system according to any one of aspects 1 to 3, wherein a first monitoring device monitors a first combination of a first mirror offset in a first MEMS array and a second mirror offset in a second MEMS array; and wherein a second monitoring device simultaneously monitors a second combination of a second mirror offset in the second MEMS array and a first mirror offset in the first MEMS array.

[0123] Aspect 5: According to the monitoring system of aspect 4, the first monitoring device has higher monitoring sensitivity to the mirror offset of the first MEMS array; and the relative positional offset between the first MEMS array and the second MEMS array is monitored.

[0124] Aspect 6: The monitoring system according to any one of aspects 1 to 5, wherein the first light source includes one of the following: LED, VCSEL, FP and DFB.

[0125] Aspect 7: The monitoring system according to any one of aspects 1 to 6, wherein the lens structure includes an achromatic field lens that focuses the incident signal beam onto the center of the second MEMS array.

[0126] Aspect 8: The monitoring system according to any one of aspects 1 to 7, wherein the first monitoring device includes an image relay lens structure, a camera lens, and a sensor array.

[0127] Aspect 9: The monitoring system according to aspect 8, wherein the first monitoring device further includes a microlens array disposed between the camera lens and the sensor array.

[0128] Aspect 10: The monitoring system according to any one of aspects 1 to 9 further includes: a second light source that generates a second reference beam; a second optical device that reflects and transmits light; and a second filter located between the output collimator array and the second lens structure; the second filter receiving the second reference beam from the second optical device and allowing the second reference beam to pass through the second MEMS array and the first MEMS array.

[0129] Aspect 11: A method for monitoring an optical path switching device, the method comprising: generating a first reference beam via a first light source; receiving the first reference beam from a first optical device via a first filter located between an input collimator array and a lens structure, the first reference beam being transmitted and reflected light; passing the first reference beam through a first MEMS array and a second MEMS array via the first filter; receiving the first reference beam via a first monitoring device, the first reference beam monitoring at least a first mirror offset in the first MEMS array; and simultaneously receiving a second reference beam via a second monitoring device, the second reference beam monitoring at least a second mirror offset in the second MEMS array.

[0130] Aspect 12: According to the method of aspect 11, the first light source includes a collimating reference light source.

[0131] Aspect 13: The method according to any one of aspects 11 to 12, wherein the first optical device comprises one of the following: PBS, beam splitter, WDM filter, coupler and circulator.

[0132] Aspect 14: The method according to any one of aspects 11 to 13, wherein the first monitoring device monitors a first combination of a first mirror offset in the first MEMS array and a second mirror offset in the second MEMS array; and wherein the second monitoring device simultaneously monitors a second combination of a second mirror offset in the second MEMS array and a first mirror offset in the first MEMS array.

[0133] Aspect 15: The method according to aspect 14, wherein the first monitoring device has higher monitoring sensitivity to the mirror offset of the first MEMS array; wherein the second monitoring device has higher monitoring sensitivity to the mirror offset of the second MEMS array; and wherein the relative positional offset between the first MEMS array and the second MEMS array is monitored.

[0134] Aspect 16: The method according to any one of aspects 11 to 15, wherein the first light source includes one of the following: LED, VCSEL, FP, and DFB.

[0135] Aspect 17: The method according to any one of aspects 11 to 16, wherein the lens structure includes an achromatic field lens that focuses the incident signal beam onto the center of the second MEMS array.

[0136] Aspect 18: The method according to any one of aspects 11 to 17, wherein the first monitoring device includes an image relay lens structure, a camera lens, and a sensor array.

[0137] Aspect 19: The method according to aspect 18, wherein the first monitoring device further includes a microlens array disposed between the camera lens and the sensor array.

[0138] Aspect 20: The method according to any one of aspects 11 to 19 further includes: generating a second reference beam via a second light source; receiving the second reference beam from a second optical device of reflected light and transmitted light via a second filter located between an output collimator array and a second lens structure; and passing the second reference beam through a second MEMS array and a first MEMS array via the second filter.

[0139] Aspect 21: A monitoring system for an optical path switching device, the monitoring system comprising: a first collimator array having two or more input ports receiving a test beam from at least one test light source generating a test beam; a first MEMS array and a second MEMS array receiving the test beam from the two or more input ports and guiding the received test beam to a second collimator array; a second collimator array including two or more output ports receiving the test beam from the first MEMS array and the second MEMS array; and at least one test light detection device connected to the two or more output ports receiving the test beam, wherein the at least one test light detection device monitors the optical path switching device.

[0140] Aspect 22: In the monitoring system according to aspect 21, at least one test light source includes a collimated light source.

[0141] Aspect 23: A monitoring system according to any one of Aspects 21 to 22, wherein at least one test light detection device measures the insertion loss of each test beam and its variation.

[0142] Aspect 24: According to the monitoring system of aspect 23, the first MEMS array includes a first matrix of mirrors, the second MEMS array includes a second matrix of mirrors; and wherein when the measured change in insertion loss is greater than a predetermined threshold, the first matrix and the second matrix return to an optimized position for further testing.

[0143] Aspect 25: The monitoring system according to any one of aspects 21 to 24 further includes: a first reference light source that generates a first reference beam; a first optical device that transmits and reflects light; a first filter located between a first collimator array and a lens structure; the first filter receiving the first reference beam from the first optical device and allowing the first reference beam to pass through a first MEMS array and a second MEMS array; a first monitoring device that receives the first reference beam, the first reference beam monitoring at least the offset of a first mirror in the first MEMS array; and a second monitoring device that simultaneously receives a second reference beam, the second reference beam monitoring at least the offset of a second mirror in the second MEMS array.

[0144] Aspect 26: According to the monitoring system of aspect 25, the first reference beam and the second beam are generated after at least one test light detection device determines that the measured insertion loss change of each test beam is greater than a predetermined threshold.

[0145] Aspect 27: A monitoring system according to any one of aspects 21 to 26, wherein two or more input ports comprise sixteen input ports divided into two groups; and wherein two or more output ports comprise sixteen output ports corresponding to each of the sixteen input ports.

[0146] Aspect 28: The monitoring system according to any one of aspects 21 to 27, wherein at least one test light source includes one of the following: LED, VCSEL, FP and DFB.

[0147] Aspect 29: In the monitoring system according to aspect 28, at least one test light source has the same wavelength as the signal used by the optical path switching device.

[0148] Aspect 30: The monitoring system according to any one of aspects 21 to 29, wherein at least one test light source comprises two light sources, which are combined by a coupler and assigned to an input optical port.

[0149] Aspect 31: A method for monitoring an optical path switching device, the method comprising: generating a test beam from at least one test light source; receiving the test beam by a first collimator array having two or more input ports; passing the test beam through a first MEMS array and a second MEMS array via the two or more input ports; receiving the test beam through two or more output ports of a second collimator array; receiving the test beam through at least one test light detection device; and measuring the insertion loss of the optical path switching device and its variation using the test beam.

[0150] Aspect 32: According to the method of aspect 31, at least one test light source includes a collimating reference light source.

[0151] Aspect 33: The method according to any one of aspects 31 to 32, wherein the first MEMS array includes a first matrix of mirrors, the second MEMS array includes a second matrix of mirrors; and when the measured insertion loss change is greater than a predetermined threshold, the first matrix and the second matrix are returned to an optimized position for further testing.

[0152] Aspect 34: The method according to any one of aspects 31 to 33 further includes: generating a first reference beam through a first reference light source when the measured insertion loss change is greater than a predetermined threshold; receiving the first reference beam from a first optical device for transmitting and reflecting light via a first filter located between a first collimator array and a lens structure; passing the first reference beam through a first MEMS array and a second MEMS array via the first filter; receiving the first reference beam via a first monitoring device, the first reference beam monitoring at least the offset of a first mirror in the first MEMS array; and simultaneously receiving a second reference beam via a second monitoring device, the second reference beam monitoring at least the offset of a second mirror in the second MEMS array.

[0153] Aspect 35: The method according to aspect 34 further includes: generating a second reference beam via a second light source; receiving the second reference beam from a second optical device for reflected and transmitted light via a second filter located between a second collimator array and a second lens structure; and passing the second reference beam through a second MEMS array and a first MEMS array via the second filter.

[0154] Aspect 36: The method according to any one of aspects 34 to 35, wherein the first monitoring device has higher monitoring sensitivity to the mirror offset of the first MEMS array; wherein the second monitoring device has higher monitoring sensitivity to the mirror offset of the second MEMS array; and wherein the relative positional offset between the first MEMS array and the second MEMS array is monitored.

[0155] Aspect 37: The method according to any one of aspects 31 to 36, wherein at least one test light source comprises one of the following: LED, VCSEL, FP, and DFB.

[0156] Aspect 38: According to the method of aspect 37, at least one test light source has the same wavelength as the signal used by the optical path switching device.

[0157] Aspect 39: The method according to any one of aspects 31 to 38, wherein monitoring is performed periodically while operating the optical path switching device.

[0158] Aspect 40: According to the method of aspect 39, the optical path switch is placed in calibration mode when the insertion loss change is greater than a predetermined threshold.

[0159] Each collimator can be manufactured individually. For example, the back focal length (BFL) of each collimator can be adjusted to optimize the Gaussian waist position / Rayleigh length / pointing direction, thereby compensating for the collimator spherical ROC (radius of curvature) tolerance without compromising performance.

[0160] Those skilled in the art will understand that the various embodiments described herein have broad utility and application. Therefore, although various embodiments have been described in detail herein in conjunction with exemplary embodiments, it should be understood that this disclosure is an illustration and example of various embodiments and is intended to provide a disclosure that can be implemented. Therefore, this disclosure is not intended to be construed as limiting the embodiments or excluding any other such embodiments, adjustments, variations, modifications, and equivalent arrangements.

[0161] The foregoing description provides examples of different configurations and features of one or more embodiments. While certain terms and types of applications / hardware have been described, other names and uses of applications / hardware are possible, and the terms are provided only by way of non-limiting example. Furthermore, although specific embodiments have been described, it should be understood that the features and functions of each embodiment can be combined in any manner within the capabilities of those skilled in the art. The accompanying drawings provide additional exemplary details regarding the various embodiments.

[0162] The processes and logic flows described herein can be executed by one or more programmable processors that execute one or more computer programs to perform functions by manipulating input data and producing outputs. These processes and logic flows can also be executed by a device that can be implemented as a special-purpose logic circuit, such as an FPGA (Field-Programmable Gate Array) or an ASIC (Application-Specific Integrated Circuit).

[0163] Computer-readable media suitable for storing computer program instructions and data can include all forms of non-volatile memory, media, and storage devices, including, for example, semiconductor memory devices such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks or removable disks; magneto-optical disks; and CD-ROMs and DVD-ROMs. Processors and memory may be supplemented by or incorporated into dedicated logic circuitry.

[0164] It should be understood that variations and modifications can be made by those skilled in the art without departing from the scope of the various embodiments. Furthermore, those skilled in the art will recognize that such processes and systems need not be limited to the specific embodiments described herein. Other embodiments, combinations of these embodiments, and their uses and advantages will be apparent to those skilled in the art in light of the specification and practice of the embodiments disclosed herein. The specification and examples should be considered exemplary.

Claims

1. A monitoring system for an optical path switching device, the monitoring system comprising: The first light source generates the first reference beam; The first optical device, transmitting light and reflecting light; The first filter is located between the input collimator array and the lens structure; The first filter receives the first reference beam from the first optical device and allows the first reference beam to pass through the first microelectromechanical (MEMS) array and the second MEMS array; A first monitoring device receives the first reference beam, wherein the first reference beam at least monitors the offset of the first mirror in the first MEMS array; as well as The second monitoring device simultaneously receives a second reference beam, which monitors at least the offset of the second mirror in the second MEMS array.

2. The monitoring system according to claim 1, wherein the first light source includes a collimating reference light source.

3. The monitoring system according to any one of claims 1 to 2, wherein the first optical device comprises one of the following: a polarization beam splitter (PBS), a beam splitter, a wavelength division multiplexing (WDM) filter, a coupler, and a circulator.

4. The monitoring system according to any one of claims 1 to 3, The first monitoring device monitors a first combination of the offset of the first mirror in the first MEMS array and the offset of the second mirror in the second MEMS array; and The second monitoring device simultaneously monitors a second combination of the offset of the second mirror in the second MEMS array and the offset of the first mirror in the first MEMS array.

5. The monitoring system according to claim 4, The first monitoring device has higher monitoring sensitivity for the mirror offset of the first MEMS array; The second monitoring device has higher sensitivity to the mirror offset of the second MEMS array; and The relative positional offset between the first MEMS array and the second MEMS array is monitored.

6. The monitoring system according to any one of claims 1 to 5, wherein the first light source comprises one of the following: a light-emitting diode (LED), a vertical-cavity surface-emitting laser (VCSEL), a Fabry-Perot laser (FP), and a distributed feedback laser (DFB).

7. The monitoring system according to any one of claims 1 to 6, wherein the lens structure includes an achromatic field lens, the achromatic field lens focusing the incident signal beam onto the center of the second MEMS array.

8. The monitoring system according to any one of claims 1 to 7, wherein the first monitoring device comprises an image relay lens structure, a camera lens, and a sensor array.

9. The monitoring system according to claim 8, wherein the first monitoring device further comprises a microlens array disposed between the camera lens and the sensor array.

10. The monitoring system according to any one of claims 1 to 9, further comprising: A second light source, which generates the second reference beam; The second optical device, which reflects and transmits light; as well as The second filter is located between the output collimator array and the second lens structure; The second filter receives the second reference beam from the second optical device and allows the second reference beam to pass through the second MEMS array and the first MEMS array.

11. A method for monitoring an optical path switching device, the method comprising: A first reference beam is generated via a first light source; The first reference beam from the first optical device receives transmitted and reflected light via a first filter located between the input collimator array and the lens structure; The first reference beam passes through the first microelectromechanical (MEMS) array and the second MEMS array via the first filter. The first reference beam is received via a first monitoring device, and the first reference beam at least monitors the offset of the first reflector in the first MEMS array. as well as Simultaneously, a second reference beam is received via a second monitoring device, the second reference beam at least monitoring the offset of the second mirror in the second MEMS array.

12. The method of claim 11, wherein the first light source comprises a collimating reference light source.

13. The method according to any one of claims 11 to 12, wherein the first optical device comprises one of: a polarizing beam splitter (PBS), a beam splitter, a wavelength division multiplexing (WDM) filter, a coupler, and a circulator.

14. The method according to any one of claims 11 to 13, The first monitoring device monitors a first combination of the offset of the first mirror in the first MEMS array and the offset of the second mirror in the second MEMS array; and The second monitoring device simultaneously monitors a second combination of the offset of the second mirror in the second MEMS array and the offset of the first mirror in the first MEMS array.

15. The method according to claim 14, The first monitoring device has higher monitoring sensitivity for the mirror offset of the first MEMS array; The second monitoring device has higher sensitivity to the mirror offset of the second MEMS array; and The relative positional offset between the first MEMS array and the second MEMS array is monitored.

16. The method according to any one of claims 11 to 15, The first light source includes one of the following: a light-emitting diode (LED), a vertical-cavity surface-emitting laser (VCSEL), a Fabry-Perot laser (FP), and a distributed feedback laser (DFB).

17. The method according to any one of claims 11 to 16, wherein the lens structure comprises an achromatic field lens that focuses the incident signal beam onto the center of the second MEMS array.

18. The method according to any one of claims 11 to 17, wherein the first monitoring device comprises an image relay lens structure, a camera lens, and a sensor array.

19. The method of claim 18, wherein the first monitoring device further comprises a microlens array disposed between the camera lens and the sensor array.

20. The method according to any one of claims 11 to 19, further comprising: The second reference beam is generated via a second light source; The second reference beam is received from the reflected and transmitted light by a second optical device via a second filter located between the output collimator array and the second lens structure; and The second reference beam is passed through the second MEMS array and the first MEMS array via the second filter.

21. A monitoring system for an optical path switching device, the monitoring system comprising: A first collimator array having two or more input ports that receive the test beam from at least one test light source that generates the test beam; A first microelectromechanical (MEMS) array and a second MEMS array receive the test beam from the two or more input ports and guide the received test beam to a second collimator array; The second collimator array includes two or more output ports that receive the test beam from the first MEMS array and the second MEMS array; as well as At least one test light detection device is connected to the two or more output ports that receive the test beam, wherein the at least one test light detection device monitors the optical path switching device.

22. The monitoring system according to claim 21, wherein the at least one test light source comprises a collimated light source.

23. The monitoring system according to any one of claims 21 to 22, wherein the at least one test light detection device measures the insertion loss and its variation in each of the test beams.

24. The monitoring system according to claim 23, The first MEMS array includes a first matrix of mirrors, and the second MEMS array includes a second matrix of mirrors; and When the measured change in insertion loss exceeds a predetermined threshold, the first matrix and the second matrix are returned to the optimized position for further testing.

25. The monitoring system according to any one of claims 21 to 24, further comprising: A first reference light source, which generates a first reference beam; The first optical device, which transmits and reflects light; A first filter is located between the first collimator array and the lens structure; The first filter receives the first reference beam from the first optical device and allows the first reference beam to pass through the first MEMS array and the second MEMS array; A first monitoring device receives the first reference beam, wherein the first reference beam at least monitors the offset of the first mirror in the first MEMS array; as well as The second monitoring device simultaneously receives a second reference beam, which monitors at least the offset of the second mirror in the second MEMS array.

26. The monitoring system of claim 25, wherein the first reference beam and the second beam are generated after the at least one test light detection device determines that the measured insertion loss change of each test beam is greater than a predetermined threshold.

27. The monitoring system according to any one of claims 21 to 26, The two or more input ports include sixteen input ports divided into two groups; and The two or more output ports include sixteen output ports corresponding to each of the sixteen input ports.

28. The monitoring system according to any one of claims 21 to 27, wherein the at least one test light source comprises one of the following: a light-emitting diode (LED), a vertical-cavity surface-emitting laser (VCSEL), a Fabry-Perot laser (FP), and a distributed feedback laser (DFB).

29. The monitoring system of claim 28, wherein the at least one test light source has the same wavelength as the signal used by the optical path switching device.

30. The monitoring system according to any one of claims 21 to 29, wherein the at least one test light source comprises two light sources, which are combined by a coupler and assigned to the input optical port.

31. A method for monitoring an optical path switching device, the method comprising: A test beam is generated from at least one test light source; The test beam is received by a first collimator array having two or more input ports; The test beam passes through the first microelectromechanical (MEMS) array and the second MEMS array via the two or more input ports. The test beam is received through two or more output ports of the second collimator array; The test beam is received by at least one test light detection device; and The insertion loss and its variation of the optical path switching device are measured using the test beam.

32. The method of claim 31, wherein the at least one test light source comprises a collimating reference light source.

33. The method according to any one of claims 31 to 32, wherein the first MEMS array comprises a first matrix of mirrors, and the second MEMS array comprises a second matrix of mirrors; and When the measured change in insertion loss exceeds a predetermined threshold, the first matrix and the second matrix are returned to the optimized position for further testing.

34. The method according to any one of claims 31 to 33, further comprising: When the measured change in insertion loss is greater than a predetermined threshold, a first reference beam is generated via a first reference light source; The first reference beam is received from the first optical device that transmits and reflects light via a first filter located between the first collimator array and the lens structure; The first reference beam passes through the first MEMS array and the second MEMS array via the first filter; The first reference beam is received via a first monitoring device, and the first reference beam at least monitors the offset of the first reflector in the first MEMS array. and The second reference beam is simultaneously received via a second monitoring device, and the second reference beam at least monitors the offset of the second mirror in the second MEMS array.

35. The method of claim 34, further comprising: The second reference beam is generated via a second light source; The second reference beam is received from the reflected and transmitted light by a second optical device via a second filter located between the second collimator array and the second lens structure; as well as The second reference beam is passed through the second MEMS array and the first MEMS array via the second filter.

36. The method according to any one of claims 34 to 35, The first monitoring device has higher monitoring sensitivity for the mirror offset of the first MEMS array; The second monitoring device has higher sensitivity to the mirror offset of the second MEMS array; and The relative positional offset between the first MEMS array and the second MEMS array is monitored.

37. The method according to any one of claims 31 to 36, wherein the at least one test light source comprises one of the following: a light-emitting diode (LED), a vertical-cavity surface-emitting laser (VCSEL), a Fabry-Perot laser (FP), and a distributed feedback laser (DFB).

38. The method of claim 37, wherein the at least one test light source has the same wavelength as the signal used by the optical path switching device.

39. The method according to any one of claims 31 to 38, wherein the monitoring is performed periodically while operating the optical path switching device.

40. The method of claim 39, wherein the optical path switch is placed in calibration mode when the insertion loss change is greater than a predetermined threshold.

Images