An optical path system for an optical switch

Abstract

This invention discloses an optical path system for an optical switch, comprising: a first single-axis crystal, a second single-axis crystal, a polarization combining prism, a total internal reflection prism, a first fiber collimator, a second fiber collimator, a third fiber collimator, a motor, and a motor controller; both the first and second single-axis crystals are cylindrical and placed with their optical axes aligned; the polarization combining prism and the total internal reflection prism are applied to radially symmetrical positions on the exit circular surface of the second single-axis crystal, and the two prisms are placed perpendicularly, with the polarization combining prism on top and the total internal reflection prism on the bottom; the first fiber collimator is located at the input end on the incident circular surface of the first single-axis crystal, the second fiber collimator is located at the output end on the exit circular surface of the second single-axis crystal, and the third fiber collimator is located at the output end of the polarization combining prism; the motor controller is used to control the rotation of the motor, thereby controlling the rotation of the second single-axis crystal.

Description

Technical Field

[0001] This invention belongs to the field of optical communication device technology, and specifically relates to an optical path system for an optical switch. Background Technology

[0002] Human life has become highly dependent on the era of fast, high-capacity information exchange networks based on fiber optic communication technology. Fiber optic communication has also evolved from relatively simple communication systems in the early days to today's optical network systems. While fiber optic communication networks bring convenience, they also place increasingly higher demands on transmission bandwidth, thus creating a demand for various optical devices and placing increasingly higher demands on their performance. As the core device of optical switching, the optical switch is one of the main factors affecting the performance of optical networks. The realization of optical networks depends entirely on the advancement of devices and system technologies such as optical switches, optical filters, next-generation all-optical amplification technology, and dense wavelength division multiplexing technology.

[0003] Optical switches, as core switching elements in high-speed, high-capacity DWDM optical transmission and switching systems, are crucial in determining node and network performance. They are primarily used for optical layer functions such as routing, wavelength selection, optical cross-connection, optical add-drop multiplexers, self-healing protection, optical network monitoring, and communication device testing. Furthermore, optical switches are widely used in many other fiber optic sensing applications. Over the past two to three decades, researchers and related companies have made continuous progress in optical switches and related technologies, principles, materials, and fabrication processes. They continue to research and produce optical switches with higher isolation, lower crosstalk, and shorter switching times, aiming to overcome various technological limitations. This invention utilizes a uniaxial crystal to separate, combine, and cleverly transform o-beams and e-beams, requiring fewer parts and less demanding fabrication processes, achieving low loss, high isolation, low crosstalk, and short switching times. Summary of the Invention

[0004] This invention aims to address the shortcomings of existing technologies and provides the following solutions:

[0005] An optical path system for an optical switch includes: a first single-axis crystal, a second single-axis crystal, a polarization combining prism, a total internal reflection prism, a first fiber collimator, a second fiber collimator, a third fiber collimator, a motor, and a motor controller;

[0006] Both the first uniaxial crystal and the second uniaxial crystal are cylindrical and are placed with the same optical axis direction;

[0007] The polarizing beam combiner prism and the total internal reflection prism are optically bonded to the radially symmetrical position of the exit circular surface of the second uniaxial crystal, and the two prisms are placed in a vertical direction, with the polarizing beam combiner prism on top and the total internal reflection prism on the bottom.

[0008] The first fiber collimator is disposed at the input end on the incident circular surface of the first uniaxial crystal, the second fiber collimator is disposed at the output end on the exit circular surface of the second uniaxial crystal, and the third fiber collimator is disposed at the output end of the polarization combining prism.

[0009] The motor controller is used to control the rotation of the motor, and in turn, control the rotation of the second uniaxial crystal.

[0010] Preferably, the first uniaxial crystal and the second uniaxial crystal are made of the same material, and each circular surface is polished to a surface finish of grade 12 or higher; each circular surface of the first uniaxial crystal and the second uniaxial crystal is coated with a broadband high transmittance film.

[0011] Preferably, both the polarizing beam combiner prism and the reflecting prism are processed and polished to a surface finish of grade 12 or higher.

[0012] Preferably, the light beam emitted from the optical fiber becomes a parallel beam after passing through the first optical fiber collimator, and the parallel beam is incident perpendicularly on the incident surface of the first uniaxial crystal.

[0013] Preferably, the parallel beam is decomposed by the first uniaxial crystal into a vertically emitted o-beam and a downwardly deflected e-beam. The o-beam is emitted vertically from the emission surface of the first uniaxial crystal, and the e-beam is deflected downward and then refracted by the emission surface of the first uniaxial crystal before being emitted vertically.

[0014] Preferably, after the o-light is incident perpendicularly on the incident surface of the second uniaxial crystal, it forms o1 light. The o1 light travels forward to the exit surface of the second uniaxial crystal, then exits perpendicularly to the exit surface and is incident perpendicularly on the combining surface of the polarization combining prism. After the e-light is incident perpendicularly on the incident surface of the second uniaxial crystal, it is deflected downward to form e1 light. The e1 light travels downward to the exit surface of the second uniaxial crystal, is refracted, exits perpendicularly, and enters the total internal reflection prism. The e1 beam is reflected by the total internal reflection prism and transmitted to the combining surface of the polarization combining prism. Then, it is combined with the o1 light and incident from the polarization combining prism onto the third fiber collimator, and output from the output port 1.

[0015] Preferably, the second uniaxial crystal rotates 90° clockwise or counterclockwise around the horizontal optical axis under the action of the motor;

[0016] The o-light and e-light emitted perpendicularly from the exit surface of the first uniaxial crystal are transmitted to the second uniaxial crystal and incident perpendicularly on the incident surface of the second uniaxial crystal. Once incident on the second uniaxial crystal, the o-light becomes e2-light and the e-light becomes o2-light. The e2-light is deflected downwards and refracted upon reaching the exit surface of the second uniaxial crystal, then emitted perpendicularly. The o2-light is incident perpendicularly to the incident surface of the second uniaxial crystal, transmitted to the exit surface, and then emitted perpendicularly. The e2-light and o2-light are then bundled together and incident on the second fiber collimator, and output from the output port 2.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] This invention employs a circular uniaxial crystal to achieve the separation and beam combining of o-beams and e-beams, as well as the beam combining using a polarization beam combining prism. This significantly improves the optical processing accuracy of the uniaxial crystal and greatly reduces its processing difficulty. The invention uses a uniaxial crystal to separate the o-beam and e-beam, and then combines them through different paths, thereby enabling the beam to switch between different output ports. The switching time depends only on a high-speed, high-precision motor. The beam combining path cleverly rotates one of the uniaxial crystals by 90°, causing the o-beam and e-beam to switch identities when incident on the second uniaxial crystal, i.e., the o-beam transforms... The system converts o-light to e-light, and ultimately achieves the switching of the two output ports through this o-light-e-light identity conversion. The two ports can achieve good signal separation, with excellent isolation and crosstalk between them. In addition, the optical components used in the optical path system are very few and their surfaces are easy to coat, resulting in very low insertion loss. Therefore, this invention utilizes a single-axis crystal, a polarization beam combiner prism, and a total internal reflection prism, and cleverly uses a second single-axis crystal rotated by 90° to finally achieve the output port conversion of the separated o-light-e-light combined beam. It has the characteristics of simple optical path structure, low loss, high isolation, and short switching time. Attached Figure Description

[0019] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the system structure according to an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram showing the position of the prism on the second uniaxial crystal according to an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the rotation of the second uniaxial crystal according to an embodiment of the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Example

[0026] In this embodiment, as Figure 1 As shown, an optical path system for an optical switch includes: a first single-axis crystal, a second single-axis crystal, a polarization combining prism, a total reflection prism, a first fiber collimator, a second fiber collimator, a third fiber collimator, a motor, and a motor controller.

[0027] Both the first and second uniaxial crystals are cylindrical and placed with their optical axes aligned. The first and second uniaxial crystals are made of the same material; in this embodiment, YVO4 or LiNiO3 uniaxial crystals can be used, and each circular surface is polished to a finish level of 12 or higher. A wideband high-transmittance thin film is deposited on each circular surface of both the first and second uniaxial crystals.

[0028] In this embodiment, the broadband high transmittance film is a film with a relatively large wavelength range. For example, for an optical switch with a communication wavelength of 1550nm, the high transmittance film is centered at 1550nm and has a wavelength range of 1550±5nm or ±10nm.

[0029] like Figure 2 As shown, the polarizing beam combiner prism and the total internal reflection prism are optically bonded to radially symmetrical positions on the exit circular surface of the second uniaxial crystal, and the two prisms are placed perpendicularly, with the polarizing beam combiner prism on top and the total internal reflection prism on the bottom. Both the polarizing beam combiner prism and the total internal reflection prism are machined and polished to a surface finish of grade 12 or higher.

[0030] The first fiber collimator is located at the input end of the incident circular surface of the first uniaxial crystal, the second fiber collimator is located at the output end of the exit circular surface of the second uniaxial crystal, and the third fiber collimator is located at the output end of the polarization combining prism.

[0031] The motor controller is used to control the rotation of the motor, which in turn controls the rotation of the second uniaxial crystal.

[0032] The workflow of the system provided in this embodiment is described below:

[0033] The light beam emitted from the optical fiber becomes a parallel beam after passing through the first optical fiber collimator. The parallel beam is incident perpendicularly on the incident surface of the first uniaxial crystal, and then decomposes into a vertically emitted o-beam and a downwardly deflected e-beam. The o-beam is emitted perpendicularly from the exit surface of the first uniaxial crystal, and the e-beam is deflected downward and transmitted before being refracted by the exit surface of the first uniaxial crystal and emitted perpendicularly.

[0034] The emitted o-ray and e-ray propagate forward and are incident perpendicularly onto the incident surface of the second uniaxial crystal:

[0035] After the o-beam is incident perpendicularly on the incident surface of the second uniaxial crystal, it forms the o1-beam. The o1-beam travels forward to the exit surface of the second uniaxial crystal, then exits perpendicularly from the exit surface and is incident perpendicularly on the combining surface of the polarization combining prism. After the e-beam is incident perpendicularly on the incident surface of the second uniaxial crystal, it is deflected downward to form the e1-beam. The e1-beam travels downward to the exit surface of the second uniaxial crystal, is refracted, exits perpendicularly, and enters the total internal reflection prism. The e1-beam is reflected by the total internal reflection prism and transmitted to the combining surface of the polarization combining prism. Then, it is combined with the o1-beam and incident from the polarization combining prism onto the third fiber collimator, and output from output port 1.

[0036] Then, under the action of the motor, the second uniaxial crystal rotates 90° clockwise or counterclockwise around the horizontal optical axis (this optical axis is not the optical axis of the uniaxial crystal, but the optical axis of the optical switch system, i.e., the direction of the line connecting the centers of the two uniaxial crystals), as shown below. Figure 3 As shown, the optical axes of the first and second uniaxial crystals are made perpendicular to each other. In this case, the o-ray and e-ray emitted perpendicularly from the exit surface of the first uniaxial crystal are transmitted to the second uniaxial crystal and incident perpendicularly on its incident surface. Once incident on the second uniaxial crystal, the o-ray becomes e²-ray, and the e-ray becomes o²-ray. The e²-ray is deflected downwards and, upon reaching the exit surface of the second uniaxial crystal, is refracted and emitted perpendicularly to that surface (e.g., ...). Figure 1 (As shown by the dashed line in the image), while the O2 light exits perpendicularly to the incident surface of the second uniaxial crystal and propagates to the exiting surface, then exits perpendicularly to that surface (as shown by the dashed line in the image). Figure 1 (As shown by the dashed line in the image), then the e2 light and o2 light are bundled together and incident on the second fiber collimator, and output from output port 2.

[0037] When the optical signal output from output port 2 needs to be switched back to output port 1, the motor drives the second single-axis crystal to rotate 90°, so that the optical axis of the second single-axis crystal is aligned with the optical axis of the first single-axis crystal again. The switching between output port 1 and output port 2 is accomplished by the motor driving the second single-axis crystal to rotate 90°. When the optical axes are in the same direction, the optical signal is output from output port 1; when the optical axes are perpendicular, the optical signal is output from output port 2.

[0038] In this embodiment, multiple methods can also be used. Figure 1 The system shown is cascaded to form an N×M optical switch (N is greater than or equal to 1, M is greater than or equal to 2).

[0039] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An optical path system for an optical switch, characterized in that, include: The system comprises a first uniaxial crystal, a second uniaxial crystal, a polarization combining prism, a total reflection prism, a first fiber collimator, a second fiber collimator, a third fiber collimator, a motor, and a motor controller. Both the first uniaxial crystal and the second uniaxial crystal are cylindrical and are placed with the same optical axis direction; The polarizing beam combiner prism and the total internal reflection prism are optically bonded to the radially symmetrical position of the exit circular surface of the second uniaxial crystal, and the two prisms are placed in a vertical direction, with the polarizing beam combiner prism on top and the total internal reflection prism on the bottom. The first fiber collimator is disposed at the input end on the incident circular surface of the first uniaxial crystal, the second fiber collimator is disposed at the output end on the exit circular surface of the second uniaxial crystal, and the third fiber collimator is disposed at the output end of the polarization combining prism. The motor controller is used to control the rotation of the motor, and in turn control the rotation of the second single-axis crystal; The light beam emitted from the optical fiber becomes a parallel beam after passing through the first optical fiber collimator, and the parallel beam is incident perpendicularly on the incident surface of the first uniaxial crystal. The parallel beam is decomposed into a vertically emitted o-beam and a downwardly deflected e-beam by the first uniaxial crystal. The o-beam is emitted vertically from the emission surface of the first uniaxial crystal, and the e-beam is deflected downward and then refracted by the emission surface of the first uniaxial crystal before being emitted vertically. The o-beam is incident perpendicularly on the incident surface of the second uniaxial crystal, forming the o1-beam. The o1-beam travels forward to the exit surface of the second uniaxial crystal, then exits perpendicularly from the exit surface and is incident perpendicularly on the combining surface of the polarization combining prism. The e-beam is incident perpendicularly on the incident surface of the second uniaxial crystal, then deflected downwards to form the e1-beam. The e1-beam travels downwards to the exit surface of the second uniaxial crystal, is refracted, exits perpendicularly, and enters the total internal reflection prism. The e1-beam is reflected by the total internal reflection prism and transmitted to the combining surface of the polarization combining prism. It is then combined with the o1-beam and incident from the polarization combining prism onto the third fiber collimator, and output from output port 1. The second uniaxial crystal rotates 90° clockwise or counterclockwise around the horizontal optical axis under the action of the motor; The o-light and e-light emitted perpendicularly from the exit surface of the first uniaxial crystal are transmitted to the second uniaxial crystal and incident perpendicularly on the incident surface of the second uniaxial crystal. Once incident on the second uniaxial crystal, the o-light becomes e2-light and the e-light becomes o2-light. The e2-light is deflected downwards and refracted upon reaching the exit surface of the second uniaxial crystal, then emitted perpendicularly. The o2-light is incident perpendicularly to the incident surface of the second uniaxial crystal, transmitted to the exit surface, and then emitted perpendicularly. The e2-light and o2-light are then bundled together and incident on the second fiber collimator, and output from output port 2.

2. The optical path system of an optical switch according to claim 1, characterized in that, The first uniaxial crystal and the second uniaxial crystal are made of the same material, and each circular surface is polished to a surface finish of grade 12 or higher; each circular surface of the first uniaxial crystal and the second uniaxial crystal is coated with a broadband high transmittance film.

3. The optical path system of an optical switch according to claim 1, characterized in that, Both the polarizing beam combiner prism and the reflecting prism are machined and polished to a surface finish of grade 12 or higher.

Images