Optical path system of optical switch

Abstract

The invention discloses an optical path system of an optical switch. The optical path system comprises a first uniaxial crystal, a second uniaxial crystal, a polarization beam combining prism, a total reflection prism, a first optical fiber collimator, a second optical fiber collimator, a third optical fiber collimator, a motor and a motor controller, the first uniaxial crystal and the second uniaxial crystal are cylindrical and are placed in the same optical axis direction; the polarization beam combining prism and the total reflection prism are optically cemented to the radial symmetrical positions of the emergent circular surface of the second uniaxial crystal, the two prisms are placed in the vertical direction, the polarization beam combining prism is arranged on the upper portion, and the total reflection prism is arranged on the lower portion; the first optical fiber collimator is arranged at the input end of the incident circular surface of the first uniaxial crystal, the second optical fiber collimator is arranged at the output end of the emergent circular surface of the second uniaxial crystal, and the third optical fiber collimator is arranged at the output end of the polarization beam combining prism; and the motor controller is used for controlling the motor to rotate so as to control the rotation of the second uniaxial crystal.

Description

Technical Field

[0001] The invention belongs to the technical field of optical communication devices, and in particular relates to an optical path system of an optical switch. Background Art

[0002] People's lives have become highly dependent on the era of fast, large-capacity information exchange networks based on optical fiber communication technology. Optical fiber communication has also developed from a relatively simple communication system in the early days to today's optical network system. While optical fiber communication networks bring convenience to people, they also put forward higher and higher requirements for higher transmission bandwidth, which has also spawned the demand for various optical devices and put forward higher and higher requirements for their performance. As the core component of optical switching, optical switches are one of the main factors affecting the performance of optical networks. The realization of optical networks is completely dependent on the progress of components and system technologies such as optical switches, optical filters, a new generation of all-optical amplification technology, and dense wavelength division multiplexing technology.

[0003] As a switch element of the core device of the node of the high-speed, large-capacity DWDM optical transmission and switching system, the performance of the optical switch is the key to determine the node performance and network performance. It is mainly used to realize the functions of routing selection, wavelength selection, optical cross-connection, optical add-drop multiplexer, self-healing protection, monitoring of optical network, testing of communication devices, etc. at the optical level; in addition, there is a wide demand for optical switches in many other occasions such as fiber optic sensing. In the past two or three decades, researchers and related companies have made continuous progress in optical switches and related technologies, principles, materials and processing technologies, and have been committed to researching and producing optical switches with higher isolation, lower crosstalk and shorter switching time, in order to break through various process and technical limitations. The present invention uses uniaxial crystals to separate, combine and cleverly transform o-light and e-light, with fewer parts and low processing requirements, to achieve the purpose of low loss, high isolation, low crosstalk and short switching time. Summary of the invention

[0004] The present invention aims to solve the deficiencies of the prior art and provides the following solutions:

[0005] An optical path system of an optical switch, comprising: a first uniaxial crystal, a second uniaxial crystal, a polarization beam combining prism, a total reflection prism, a first optical fiber collimator, a second optical fiber collimator, a third optical fiber collimator, a motor and a motor controller;

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

[0007] The polarization beam combining prism and the total reflection prism are optically bonded to radially symmetrical positions of the exit circular surface of the second uniaxial crystal, and the two prisms are placed in a vertical direction, with the polarization beam combining prism on the top and the total reflection prism on the bottom;

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

[0009] The motor controller is used to control the rotation of the motor, thereby controlling 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 smoothness of level 12 or above; each circular surface of the first uniaxial crystal and the second uniaxial crystal is coated with a broadband high-transmittance film.

[0011] Preferably, the polarization beam combining prism and the reflecting prism are both processed and polished to a finish of grade 12 or above.

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

[0013] Preferably, the parallel light beam is decomposed into vertically emitted o-light and downwardly deflected e-light through the first uniaxial crystal. The o-light is vertically emitted on the exit surface of the first uniaxial crystal, and the e-light is deflected downward and then vertically emitted after being refracted by the exit surface of the first uniaxial crystal.

[0014] Preferably, after the o light is vertically incident on the incident surface of the second uniaxial crystal, o1 light is formed, and the o1 light moves forward to the exit surface of the second uniaxial crystal, then exits vertically from the exit surface of the second uniaxial crystal and is vertically incident on the beam combining surface of the polarization beam combining prism; after the e light is vertically incident on the incident surface of the second uniaxial crystal, it is deflected downward and transmitted to form e1 light, and the e1 light is transmitted downward to the exit surface of the second uniaxial crystal and is refracted, then exits vertically and enters the total reflection prism, the e1 light beam is reflected by the total reflection mirror prism and transmitted to the beam combining surface of the polarization beam combining prism, and then is combined with the o1 light and incident from the polarization beam combining prism to the third fiber collimator, and is 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 the e light vertically emitted from the exit surface of the first uniaxial crystal are transmitted to the second uniaxial crystal and vertically incident 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 will be deflected downward, and will be refracted and vertically emitted when transmitted to the exit surface of the second uniaxial crystal. The o2 light is incident vertically to the incident surface of the second uniaxial crystal and is transmitted to the exit surface and then vertically emitted. Then the e2 light and the o2 light are combined and incident on the second optical fiber collimator and output from the output port 2.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention adopts a circular uniaxial crystal to realize the separation and combination of o-light and e-light and the combination of polarization beam combining prism, which greatly improves the optical processing accuracy of uniaxial crystals and greatly reduces the processing difficulty of uniaxial crystals; the present invention adopts a uniaxial crystal to separate the light beam into o-light and e-light, and then combines the o-light and e-light through different paths, so as to realize the switching of light beams from different output ports, and the switching time only depends on the high-speed and high-precision motor. The combination path of o-light and e-light cleverly rotates one of the uniaxial crystals by 90°, so that the o-light and e-light change their identities when they are incident on the second uniaxial crystal, that is, the o-light becomes The o-light is converted into e-light, and the e-light is converted into e-light, and finally the switching of the two output ports is realized through the identity conversion of the o-light and e-light. The two ports can achieve good signal separation, and have good isolation and crosstalk with each other. In addition, the optical components used in the optical path system are very few and the surfaces are very easy to be coated, so they have very low insertion loss. Therefore, the present invention utilizes uniaxial crystals, polarization beam combining prisms, and total reflection prisms, and cleverly utilizes the second uniaxial crystal to rotate 90° to finally realize the output port conversion of the separated o-light e-light combined beam, which has the characteristics of simple optical path structure, low loss, high isolation, and short switching time. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1 A schematic diagram of the system structure of an embodiment of the present invention;

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

[0022] Figure 3 FIG. 4 is a schematic diagram of a second uniaxial crystal rotation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Example

[0026] In this embodiment, if Figure 1 As shown, an optical path system of an optical switch includes: a first uniaxial crystal, a second uniaxial crystal, a polarization beam 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] The first uniaxial crystal and the second uniaxial crystal are both cylindrical and placed in the same optical axis direction. The first uniaxial crystal and the second uniaxial crystal are made of the same material. In this embodiment, uniaxial crystals such as YVO4 or LiNiO3 can be used, and each circular surface is processed and polished to a finish of level 12 or above; each circular surface of the first uniaxial crystal and the second uniaxial crystal is coated with a broadband high-transmittance film.

[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, a high transmittance film with a wavelength of 1550±5nm or ±10nm is used with 1550nm as the center.

[0029] like Figure 2 As shown, the polarization beam combining prism and the total 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 polarization beam combining prism on the top and the total reflection prism on the bottom. The polarization beam combining prism and the reflection prism are both processed and polished to a finish of 12 or above.

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

[0031] The motor controller is used to control the rotation of the motor, thereby controlling the rotation of the second uniaxial crystal.

[0032] The following describes the workflow of the system provided in this embodiment:

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

[0034] The outgoing o-light and e-light are transmitted forward and vertically incident on the incident surface of the second uniaxial crystal:

[0035] After the o light is vertically incident on the incident surface of the second uniaxial crystal, o1 light is formed. The o1 light goes forward to the exit surface of the second uniaxial crystal, then exits vertically from the exit surface of the second uniaxial crystal and is vertically incident on the beam combining surface of the polarization beam combining prism; the e light is vertically incident on the incident surface of the second uniaxial crystal and is deflected and transmitted downward to form e1 light. The e1 light is transmitted downward to the exit surface of the second uniaxial crystal and is refracted before exiting vertically and entering the total reflection prism. The e1 light beam is reflected by the total reflection mirror prism and transmitted to the beam combining surface of the polarization beam combining prism, then is combined with the o1 light and incident from the polarization beam combining prism to the third fiber collimator and output from output port 1.

[0036] Afterwards, the second uniaxial crystal is rotated 90° clockwise or counterclockwise around the horizontal optical axis (the optical axis is not the optical axis of the uniaxial crystal, but the optical axis of the optical switch optical system, i.e., the direction of the line connecting the centers of the two uniaxial crystals) by the motor. Figure 3 As shown, the optical axes of the first uniaxial crystal and the second uniaxial crystal are perpendicular to each other. At this time, the o light and the e light perpendicularly emitted from the exit surface of the first uniaxial crystal are transmitted to the second uniaxial crystal and perpendicularly incident on the incident surface of the second uniaxial crystal. Once incident on the second uniaxial crystal, the o light becomes the e2 light, and the e light becomes the o2 light. The e2 light will be deflected downward, and will be refracted when transmitted to the exit surface of the second uniaxial crystal and will be emitted perpendicularly to the surface (as shown in FIG. Figure 1 ), while the o2 light is emitted perpendicularly to the incident surface of the second uniaxial crystal and is transmitted to the exit surface and then emitted perpendicularly to the surface (as shown in the dotted line in Figure 1 Then, the e2 light and the o2 light are combined and incident on the second fiber collimator and output from the 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 uniaxial crystal to rotate 90° so that the optical axis of the second uniaxial crystal is in the same direction as the optical axis of the first uniaxial crystal. The switching between output port 1 and output port 2 is achieved by the motor driving the second uniaxial crystal to rotate 90°. When the optical axes are in the same direction, the optical signal is output from output port 1, and when the optical axes are perpendicular, the optical signal is output from output port 2.

[0038] In this embodiment, multiple Figure 1 The system shown is cascaded to form N×M optical switches (N is greater than or equal to 1, M is greater than or equal to 2).

[0039] The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. An optical path system of an optical switch, characterized in that: include: A first uniaxial crystal, a second uniaxial crystal, a polarization beam combining prism, a total reflection prism, a first fiber collimator, a second fiber collimator, a third fiber collimator, a motor, and a motor controller; The first uniaxial crystal and the second uniaxial crystal are both cylindrical and are placed with the same optical axis direction; The polarization beam combining prism and the total reflection prism are optically bonded to radially symmetrical positions of the exit circular surface of the second uniaxial crystal, and the two prisms are placed in a vertical direction, with the polarization beam combining prism on the top and the total reflection prism on the bottom; The first fiber collimator is arranged at the input end on the incident circular surface of the first uniaxial crystal, the second fiber collimator is arranged at the output end on the exit circular surface of the second uniaxial crystal, and the third fiber collimator is arranged at the output end of the polarization beam combining prism; The motor controller is used to control the rotation of the motor, thereby controlling the rotation of the second uniaxial crystal.

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 processed and polished to a finish of level 12 or above; 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: The polarization beam combining prism and the reflecting prism are both processed and polished to a finish of grade 12 or above.

4. The optical path system of an optical switch according to claim 1, characterized in that: The light beam emitted from the optical fiber becomes a parallel light beam after passing through the first optical fiber collimator, and the parallel light beam is vertically incident on the incident surface of the first uniaxial crystal.

5. The optical path system of an optical switch according to claim 4, characterized in that: The parallel light beam is decomposed into vertically emitted o-light and downwardly deflected e-light through the first uniaxial crystal. The o-light is vertically emitted on the exit surface of the first uniaxial crystal, and the e-light is deflected downward and then vertically emitted after being refracted by the exit surface of the first uniaxial crystal.

6. The optical path system of an optical switch according to claim 5, characterized in that: After the o light is vertically incident on the incident surface of the second uniaxial crystal, o1 light is formed, and the o1 light goes forward to the exit surface of the second uniaxial crystal, then exits vertically from the exit surface of the second uniaxial crystal and is vertically incident on the beam combining surface of the polarization beam combining prism; after the e light is vertically incident on the incident surface of the second uniaxial crystal, it is deflected downward and transmitted to form e1 light, and the e1 light is transmitted downward to the exit surface of the second uniaxial crystal and is refracted, then exits vertically and enters the total reflection prism, the e1 light beam is reflected by the total reflection mirror prism and transmitted to the beam combining surface of the polarization beam combining prism, and then is combined with the o1 light and incident from the polarization beam combining prism to the third fiber collimator, and output from the output port 1.

7. The optical path system of an optical switch according to claim 5, characterized in that: The second uniaxial crystal rotates 90° clockwise or counterclockwise around the horizontal optical axis under the action of the motor; The o light and the e light vertically emitted from the exit surface of the first uniaxial crystal are transmitted to the second uniaxial crystal and vertically incident 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 will be deflected downward, and will be refracted and vertically emitted when transmitted to the exit surface of the second uniaxial crystal. The o2 light is incident vertically to the incident surface of the second uniaxial crystal and is transmitted to the exit surface and then vertically emitted. Then the e2 light and the o2 light are combined and incident on the second optical fiber collimator and output from the output port 2.

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