A multi-channel polarization multiplexing and wavelength division multiplexing hybrid module
By introducing the wavelength division multiplexing function into the polarization multiplexing module, the multi-channel polarization multiplexing and wavelength division multiplexing mixing modules are designed, which solves the problem of low utilization of fiber resources in the prior art, and realizes efficient utilization of optical fiber communication capacity, which can transmit 2N signals in the same optical fiber.
Patent Information
- Application Number
- CN202510080137.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-19
- Publication Date
- 2025-04-04
AI Technical Summary
In the prior art, polarization multiplexing products cannot carry wavelength information, resulting in low utilization of fiber resources and communication resources. In addition, conventional multi-channel wavelength division multiplexing modules can only transmit N wavelengths without superimposed polarization states, which limits the utilization of fiber communication capacity.
A multi-channel polarization multiplexing and wavelength division multiplexing mixing module is designed. By adding the wavelength division multiplexing function on the basis of simple polarization multiplexing/demultiplexing, the polarized signal can load a specific wavelength signal. The module includes an incident fiber collimator and N exit modules, each exit module includes a filter, a birefringent crystal and a dual fiber polarization collimator, realizing the multiplexing of multiple channels of wavelength and polarization state.
Through this module, 2N signals can be loaded at N different wavelengths. The wavelength and polarization state of the signals are different without interference. They can be transmitted simultaneously in the same optical fiber, which is equivalent to changing the capacity of the optical fiber signal to 2N times, expanding the usage scenario and monitoring the state changes of multiple targets at the same time.
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Figure CN119758531A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of optical fiber communication, in particular to a multi-channel polarization multiplexing and wavelength division multiplexing hybrid module. Background Art
[0002] The polarization multiplexing product solutions currently available on the market are polarization beam combiners PBC / beam splitters PBS. The polarization signals multiplexed / demultiplexed by this solution cannot carry wavelength information and can only distinguish two polarization state information. Therefore, the information carrying these two polarization states can be transmitted in two states in one optical fiber, which is equivalent to one optical fiber only transmitting two signals, resulting in low utilization of optical fiber resources and communication resources. Conventional multi-channel (the number of channels is represented by N) wavelength division multiplexing modules use free space optical paths for serial connection, such as Figure 1 As shown, the first channel is first described as an example. The first channel is composed of an ordinary single-fiber collimator 01, an optical filter 02, and an ordinary single-fiber collimator 10, wherein the optical fiber 11 is an ordinary optical fiber used as a common end, and the optical fiber 101 is an ordinary optical fiber used as an output end. The multi-wavelength signal λ1...λn is input from the optical fiber 11, and then filtered by the optical filter 02, and the wavelength λ1 can be transmitted and the wavelength λ2...λn can be reflected. The transmission wavelength signal λ1 is focused by the single-fiber collimator 10 to the optical fiber 101 for reception and transmission. The second channel is composed of an optical filter 04 and an ordinary single-fiber collimator 20. The optical fiber 201 is an ordinary optical fiber used as an output end. Its signal is input from the single-fiber collimator 01 and obtained after reflection by the optical filter 02. After filtering by the optical filter 04, the wavelength signal λ2 can be transmitted and the wavelength λ3...λn can be reflected. The transmission wavelength λ2 is focused by the single-fiber collimator 20 to the optical fiber 201 for reception and transmission. The same logic can be applied to complete the filtering or loading output of multi-channel N wavelengths.
[0003] From the above optical transmission process, it can be seen that a single polarization device PBC / PBS can only transmit two polarization states, while a conventional multi-channel wavelength division multiplexing device or module can only transmit N wavelengths without superimposed polarization states. Both are single transmission modes, and the communication capacity of optical fiber is not used more effectively. Summary of the invention
[0004] In response to the above problems, the present invention provides a multi-channel polarization multiplexing and wavelength division multiplexing hybrid module, which adds a wavelength division multiplexing function on the basis of simple polarization multiplexing / demultiplexing, so that the polarization signal can also load a specific wavelength signal, which can expand more usage scenarios and monitor the status changes of multiple targets at the same time in complex situations.
[0005] The technical solution adopted by the present invention is: A multi-channel polarization multiplexing and wavelength division multiplexing hybrid module comprises an incident optical fiber collimator for an incident optical signal and N output modules, where N is an integer greater than 2, and each output module comprises a filter for filtering the optical signal, a birefringent crystal for polarizing the optical signal passing through the filter to form mutually perpendicular polarized light, and a dual-fiber polarization-maintaining collimator for allowing two perpendicular polarized lights to pass through; the multiple output modules are divided into a first output module corresponding to the incident optical fiber collimator for emitting a first optical signal, a second output module for receiving an optical signal reflected by a filter in the first output module and emitting a second optical signal... and an Nth output module for receiving an optical signal reflected by a filter in an N-1th output module and emitting an Nth optical signal.
[0006] Preferably, the plurality of emission modules are divided into a first emission module group column and a second emission module group column, the emission modules in the first emission module group column and the second emission module group column are arranged vertically, and the emission modules in the two emission module group columns are arranged in a staggered manner.
[0007] More preferably, the first emission module is in a first column of emission module groups, the emission modules in the first column of emission module groups are horizontally parallel, and the emission modules in the first column of emission module groups are obliquely parallel.
[0008] Preferably, the polarization-maintaining dual-fiber collimator comprises a polarization-maintaining lens and two polarization-maintaining optical fibers disposed in the lens, and the two polarization-maintaining optical fibers are arranged vertically or horizontally.
[0009] Preferably, the birefringent crystal is calcite.
[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides a multi-channel polarization multiplexing and wavelength division multiplexing hybrid module, which adds a wavelength division multiplexing function on the basis of simple polarization multiplexing / demultiplexing, so that polarization signals can also load specific wavelength signals, and the signals are connected in series through free space optical paths. N different wavelengths have 2N signals multiplexed on one optical fiber. Since the wavelengths and polarization states of the 2N signals are different and will not interfere with each other, they can be transmitted simultaneously on the same optical fiber, which is equivalent to increasing the capacity of the optical fiber signal by 2N times, which can expand more usage scenarios and monitor the status changes of multiple targets at the same time in complex situations. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 The figure is a schematic diagram of a typical multi-channel wavelength division multiplexing module structure in the prior art.
[0012] Figure 2 A schematic diagram of a multi-channel polarization multiplexing and wavelength division multiplexing hybrid module provided by the present invention Figure 1 .
[0013] Figure 3A schematic diagram of a multi-channel polarization multiplexing and wavelength division multiplexing hybrid module provided by the present invention Figure 2 .
[0014] Figure 4 A schematic diagram of a polarization-maintaining dual-fiber collimator for a multi-channel polarization multiplexing and wavelength division multiplexing hybrid module provided by the present invention.
[0015] Figure 5 A schematic diagram of the first implementation of the polarization-maintaining optical fiber in a multi-channel polarization multiplexing and wavelength division multiplexing hybrid module provided by the present invention.
[0016] Figure 6 A schematic diagram of the second implementation of the polarization-maintaining optical fiber in a multi-channel polarization multiplexing and wavelength division multiplexing hybrid module provided by the present invention. DETAILED DESCRIPTION
[0017] The preferred embodiments of the present invention are described in detail with reference to the accompanying drawings.
[0018] Figures 2 to 6 , which is a preferred implementation of a multi-channel polarization multiplexing and wavelength division multiplexing hybrid module provided by the present invention. Figures 2 to 6As shown, the multi-channel polarization multiplexing and wavelength division multiplexing hybrid module includes an incident optical fiber collimator 10 for an incident optical signal and N output modules 20, N is an integer greater than 2, each output module 20 includes a filter 21 for filtering the optical signal, a birefringent crystal 22 for polarizing the optical signal passing through the filter to form mutually perpendicular polarized light, and a dual-fiber polarization-maintaining collimator 23 for allowing two perpendicular polarized lights to pass through; the multiple output modules 20 are divided into a first output module 1 corresponding to the incident optical fiber collimator for emitting a first optical signal, a second output module 2 for receiving an optical signal reflected by a filter in the first output module and emitting a second optical signal... and an Nth output module N for receiving an optical signal reflected by a filter in an N-1th output module and emitting an Nth optical signal; the incident optical fiber collimator 10 is connected to an input optical fiber 11, the input optical fiber 11 is an ordinary optical fiber used as a common end, and a multi-wavelength signal λ1...λn is input from the optical fiber 11; each output module 20 is connected to an input optical fiber 11, and the input optical fiber 11 is an ordinary optical fiber used as a common end, and a multi-wavelength signal λ1...λn is input from the optical fiber 11; each output module 20 is connected to an input optical fiber 11, and the input optical fiber 11 is a common ... connected to an input optical fiber 11, and the input optical fiber 11 is a common optical fiber used as a common The module 20 forms an optical transmission channel. The dual-fiber polarization-maintaining collimator 23 of each output module 20 is connected to two polarization-maintaining optical fibers 201 and 202. The polarization-maintaining optical fibers are used as output ends. The multi-wavelength signal is filtered by the filter 21 in the first output module 1, and a wavelength λ1 can be transmitted and a wavelength λ2...λn can be reflected. The transmitted wavelength λ1 is divided into two polarization states perpendicular to each other by the birefringent crystal 22, and are respectively received by the two polarization-maintaining optical fibers 201 and 202 of the dual-fiber collimator 23. The second output module 2 receives the reflected wavelength λ2...λn. The filter 21 in the second output module 2 is filtered, and a wavelength λ2 can be transmitted and a wavelength λ3...λn can be reflected. The transmitted wavelength λ2 is divided into two polarization states perpendicular to each other by the birefringent crystal 22, and are respectively received by the two polarization-maintaining optical fibers 201 and 202 of the dual-fiber collimator 23. Similarly, the filtering of multi-channel N wavelengths and the polarization state loading output are completed.
[0019] A plurality of output modules 20 are divided into a first output module column 100 and a second output module column 200. The output modules in the first output module column 100 and the second output module column 200 are arranged longitudinally, and the output modules in the two output module columns are staggered, so that the filter 21 in the output module 20 in the rear position can receive the optical signal reflected by the filter 21 in the previous output module 20, thereby completing multi-channel N wavelength filtering and polarization state loading output.
[0020] like Figure 1 and Figure 2As shown, the first output module 1 is at the first position of the first column of the output module array 100, so that the output modules with odd numbers are distributed in the first column of the output module array 100, and the output modules with even numbers are distributed in the second column of the output module array 100. The output modules in the first column of the output module array 100 are horizontally parallel, and the output modules in the second column of the output module array 200 are obliquely parallel, so that the optical signals emitted or entered from each column of the output module array 20 are parallel.
[0021] The polarization-maintaining dual-fiber collimator 23 includes a polarization-maintaining lens 231 and two polarization-maintaining fibers 201 and 202 disposed in the lens. The two polarization-maintaining fibers are arranged vertically or horizontally. The polarization-maintaining dual-fiber collimator 23 is assembled from two polarization-maintaining fibers 201 and 202 plus a polarization-maintaining lens 231. Draw the dual-fiber structure separately to observe the fiber arrangement. Figure 4 As shown in the left view, it can be seen that the two polarization-maintaining optical fibers 201 and 202 are arranged vertically, which is an implementation scheme. It can also be arranged horizontally. The spacing between the polarization-maintaining optical fibers 201 and 202 can be adjusted according to actual needs. After enlarging the polarization-maintaining optical fibers 201 and 202 and observing them, it can be seen that the connection lines of the polarization-maintaining optical fiber stress mechanisms are perpendicular to each other, as shown in FIG. Figure 5 is one of the implementation cases, such as Figure 6 This is another implementation example, and other arrangements may be made as needed, and other similar polarization-maintaining optical fibers may also be used.
[0022] The birefringent crystal is calcite, which is a common birefringent crystal with an obvious birefringent effect. Its refractive index varies greatly in different directions, so it can split the incident light into two beams of light with different propagation directions.
[0023] The multi-channel polarization multiplexing and wavelength division multiplexing hybrid module provided by the present invention uses wavelength division multiplexing technology and polarization multiplexing technology at the same time, and can realize specific wavelength polarization multiplexing (MUX) and demultiplexing (DEMUX). Each output module forms a channel.
[0024] The demultiplexing (DEMUX) principle is as follows Figure 2As shown, the first channel formed by the first output module is first described as an example. The multi-wavelength signal λ1...λn is input from the input optical fiber 11 connected to the incident optical fiber collimator 10, and is filtered by the filter 21 of the first output module 1. The wavelength λ1 can be transmitted and the wavelength λ2...λn can be reflected. The transmitted wavelength λ1 is divided into two polarized lights with mutually perpendicular polarization states by the birefringent crystal 22, and are respectively received by the two polarization-maintaining optical fibers 201 and 202 of the dual-fiber collimator 23 and transmitted while maintaining the polarization state; the second channel The signal is input from the single-fiber collimator 01 and obtained after being reflected by the filter 21 of the first output module 1, and is filtered by the filter 21 of the second output module 2, so that the wavelength λ2 can be transmitted and the wavelength λ3...λn can be reflected. The transmitted wavelength λ2 is divided into two polarization states perpendicular to each other by the birefringent crystal 22, and is respectively received by the two polarization-maintaining optical fibers 201 and 202 of the dual-fiber collimator 23 and transmitted while maintaining the polarization state; and so on, the filtering of multi-channel N wavelengths and the polarization state loading output are completed.
[0025] The multiplexing (MUX) principle is as follows Figure 3 As shown, the first channel formed by the first output module is first used as an example for explanation. The mutually perpendicular polarized lights are respectively input from the polarization-maintaining fibers 201 and 202. After being focused by the polarization-maintaining lens 231 of the dual-fiber collimator 23, the polarization states are still mutually perpendicular. Then, they enter the birefringent crystal 22 and are merged together. Then, they are filtered by the filter 21, and two light signals with mutually perpendicular polarization states but the same wavelength (both wavelengths are λ1) can be transmitted. The two light signals with the same wavelength of λ1 but perpendicular polarization states are received by the common incident single-fiber collimator 10, and are coupled by the incident fiber 11 and transmitted while maintaining mutually perpendicular polarization states. ; Let's take the second channel formed by the second output module 2 as an example. The mutually perpendicular polarized lights are input from the polarization-maintaining fibers 201 and 202 respectively. After being focused by the polarization-maintaining lens 231, the polarization states are still perpendicular to each other. Then they enter the birefringent crystal 22 and merge together. Then they are filtered by the optical filter 21, and two optical signals with mutually perpendicular polarization states but the same wavelength (both wavelengths are λ2) can be transmitted. The two optical signals with the same wavelength of λ2 but perpendicular polarization states are reflected by the optical filter 02 and then enter the common incident single fiber collimator 10 for reception. They are coupled by the incident fiber 11 and transmitted while maintaining mutually perpendicular polarization states. Similarly, the loading of multi-channel N wavelengths and the output of polarization state multiplexing are completed.
[0026] Further explanation, the demultiplexing (DEMUX) principle ( Figure 2From left to right) is to separate the optical signal carrying a specific wavelength into two polarization signal lights o and e with mutually perpendicular polarization states, which are output from polarization-maintaining optical fibers 201 and 202 respectively. One optical signal carrying a wavelength is divided by the birefringent crystal 22 into two signals with mutually perpendicular polarization states but the same wavelength, which is equivalent to doubling the capacity; and the multiplexing principle (MUX) is ( Figure 3 (From right to left) Two mutually perpendicular polarization signals are input from two polarization-maintaining fibers 201 and 202 respectively, merged through a birefringent crystal 22, and then loaded with a specified wavelength through a filter. Since the polarization-maintaining fiber can maintain the polarization state of the signal for transmission, the two merged signals can be transmitted simultaneously in one fiber without interference. The same wavelength signal is loaded with two polarization states, which is equivalent to doubling the capacity of the fiber signal. Similarly, N different wavelengths are loaded with two polarization states to form 2N different signals. 2N signals are connected in series through a free space optical path, and 2N signals are multiplexed in one fiber. Since the wavelengths and polarization states of the 2N signals are different and do not interfere, they can be transmitted simultaneously in the same fiber, which is equivalent to doubling the capacity of all N wavelength signals.
[0027] In summary, the technical solution of the present invention can fully and effectively achieve the above-mentioned invention purpose, and the structure and functional principle of the present invention have been fully verified in the embodiments, and can achieve the expected effect and purpose. Without departing from the principle and essence of the present invention, various changes or modifications can be made to the embodiments of the invention. Therefore, the present invention includes all replacement contents within the scope mentioned in the scope of the patent application, and any equivalent changes made within the scope of the patent application of the present invention are within the scope of the patent application of this case.
Claims
1. A multi-channel polarization multiplexing and wavelength division multiplexing hybrid module, characterized in that: It includes an incident fiber collimator for an incident light signal and N output modules, where N is an integer greater than 2, and each output module includes a filter for filtering the light signal, a birefringent crystal for polarizing the light signal passing through the filter to form mutually perpendicular polarized light, and a dual-fiber polarization-maintaining collimator for allowing two perpendicular polarized lights to pass through; the multiple output modules are divided into a first output module corresponding to the incident fiber collimator for emitting a first light signal, a second output module for receiving a light signal reflected by a filter in the first output module and emitting a second light signal... and an Nth output module for receiving a light signal reflected by a filter in an N-1th output module and emitting an Nth light signal.
2. The multi-channel polarization multiplexing and wavelength division multiplexing hybrid module according to claim 1, characterized in that: The plurality of emission modules are divided into a first emission module group column and a second emission module group column. The emission modules in the first emission module group column and the second emission module group column are arranged vertically, and the emission modules in the two emission module group columns are arranged in a staggered manner.
3. The multi-channel polarization multiplexing and wavelength division multiplexing hybrid module according to claim 2, characterized in that: The first emission module is in the first column of emission module groups, the emission modules in the first column of emission module groups are horizontally parallel, and the emission modules in the first column of emission module groups are obliquely parallel.
4. The multi-channel polarization multiplexing and wavelength division multiplexing hybrid module according to claim 1, characterized in that: The polarization-maintaining dual-fiber collimator comprises a polarization-maintaining lens and two polarization-maintaining optical fibers arranged in the lens.
5. The multi-channel polarization multiplexing and wavelength division multiplexing hybrid module according to claim 4, characterized in that: The two polarization-maintaining optical fibers are arranged vertically or horizontally.
6. The multi-channel polarization multiplexing and wavelength division multiplexing hybrid module according to claim 1, characterized in that: The birefringent crystal is calcite.