Circulator core
By designing a circulator core containing multiple optical components, differentiation of isolation levels in different channels is achieved, and the problem of uniform isolation between ports in the prior art is solved, which improves the performance of optical communication modules and reduces costs.
Patent Information
- Application Number
- CN202420162563.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-23
- Publication Date
- 2025-03-11
- Estimated Expiration
- 2034-01-23
AI Technical Summary
In the existing circulator core structure, the isolation between the ports is uniform, making it difficult to achieve differentiation of isolation between different channels, limiting the cost and performance selection space of optical modules.
A circulator core is designed, including a first polarization spectroscopic prism, a half-wave plate, a Faraday optically active crystal, a second polarization spectroscopic prism and a turning prism, and through the combination and layout of these optical elements, the isolation degree of differentiation of different channels is achieved.
Differentiation of isolation degrees of different channels is achieved, and the requirements of optical communication module for isolation degrees, insertion losses and return losses of different ports are met, improving the performance of optical communication modules and reducing costs.
Smart Images
Figure CN222599987U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of optical fiber communication devices, in particular to a circulator core. Background Art
[0002] Optical circulator is based on magneto-optical rotation effect. It changes the direction of the light vector of linear polarized light by controlling the magnetic field to complete the directional propagation of multi-port input and output. Its function is to make the optical signal only transmitted along the specified port sequence. When the optical signal is input from the specified port, it can only be output along the specified port in the device. When the transmission order of the optical signal is changed, that is, when it is not transmitted according to the specified port, its loss is very large, which can achieve the isolation of the input signal.
[0003] The isolation between ports of the currently widely used circulator core structure is the same, either multi-stage isolation or single-stage isolation, and usually additional optical isolators or multiple circulator cores are added to the circulator structure to achieve the purpose of multi-stage isolation, which limits the cost and optical performance selection space of the optical module. Summary of the invention
[0004] The utility model aims to provide a circulator core, which can achieve differentiation of isolation between different channels.
[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a circulator core, comprising a first polarization beam splitter prism, a half-wave plate, a Faraday rotator crystal, a second polarization beam splitter prism and a turning prism arranged in sequence; the cross section of the first polarization beam splitter prism is an isosceles trapezoid with a base angle of 45°, which is used to input signal light, and a first polarization beam splitter film is arranged inside the first polarization beam splitter prism, which is used to separate or synthesize P polarized light and S polarized light in the signal light; the half-wave plate and the Faraday rotator crystal are bonded together, which are used to rotate the polarization of signal light in a single transmission direction by 90°, and not to rotate the polarization of signal light in another transmission direction; the cross section of the second polarization beam splitter prism is a right-angled trapezoid with a base angle of 45°, which is used to output signal light, and a second polarization beam splitter film is arranged inside the first polarization beam splitter prism, which is used to separate or synthesize P polarized light and S polarized light in the signal light; the cross section of the turning prism is an isosceles right triangle, which is used to reflect signal light and make a 180° turn in the transmission direction of the signal light;
[0006] The lower part of the long side end face where the long base of the cross section of the first polarization beam splitter prism is located is bonded to one end face of the half-wave plate, the upper and lower end faces where the upper and lower waist sides of the cross section of the first polarization beam splitter prism are located are both provided with high reflection films, the first polarization beam splitter film is parallel to the lower end face of the first polarization beam splitter prism, the other end face of the half-wave plate is bonded to one end face of the Faraday rotator crystal, the other end face of the Faraday rotator crystal is bonded to the long side end face where the long base of the cross section of the second polarization beam splitter prism is located, the upper end face where the oblique waist side of the cross section of the second polarization beam splitter prism is located is provided with a high reflection film, the second polarization beam splitter film is parallel to the upper end face of the second polarization beam splitter prism, and the lower end face where the right-angle waist side of the cross section of the second polarization beam splitter prism is located is bonded to the bottom face of the turning prism;
[0007] The circulator core has three signal ports, the first signal port is located on the upper part of the long side end face of the first polarization beam splitter prism, the second signal port is located on the short side end face where the short bottom side of the cross section of the first polarization beam splitter prism is located, and the third signal port is located on the short side end face where the short bottom side of the cross section of the second polarization beam splitter prism is located.
[0008] Furthermore, the positions of the half-wave plate and the Faraday rotator crystal can be interchanged.
[0009] Furthermore, all the bonding surfaces and signal port surfaces of the circulator core are provided with anti-reflection films.
[0010] Furthermore, the angle at which the signal light enters the circulator core, that is, the angle between the incident direction of the signal light entering the first polarization beam splitter prism from the first signal port and the normal direction of the long side end face of the first polarization beam splitter prism, is 1-5°.
[0011] Compared with the prior art, the utility model has the following beneficial effects: the utility model provides a circulator core that can achieve differentiated isolation of different channels, meets the requirements of the optical communication module (transceiver) for isolation, insertion loss and return loss of different ports, ensures that the return loss of each channel is >70dB, and the output light of the three ports remains parallel, which is convenient for the coupler to adjust the coupling, the optical path of P light and S light inside the circulator core is consistent, and the PMD loss is low, which is of great help to improve the performance of the optical communication module (transceiver) and reduce the cost. The circulator core can be flexibly integrated into various functional devices or modules (such as optical transceiver modules). Therefore, the utility model has strong practicality and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 It is a 3D structural schematic diagram of the circulator core of an embodiment of the utility model;
[0013] Figure 2It is a schematic diagram of the planar structure of the circulator core of an embodiment of the utility model;
[0014] Figure 3 It is a schematic diagram of light propagation from the first signal port to the turning prism in an embodiment of the utility model;
[0015] Figure 4 It is a schematic diagram of light propagation in which light propagates from the first signal port to the turning prism and then propagates from the turning prism to the second signal port in the embodiment of the utility model;
[0016] Figure 5 It is a schematic diagram of light propagation from the second signal port to the third signal port in an embodiment of the utility model.
[0017] In all the drawings, the same reference numerals represent the same technical features, the solid line portion represents P-polarized light transmission, and the dotted line portion represents S-polarized light transmission. DETAILED DESCRIPTION
[0018] The utility model is further described below in conjunction with the accompanying drawings and embodiments.
[0019] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.
[0020] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.
[0021] like Figure 1-2 As shown, this embodiment provides a circulator core, including a first polarization beam splitter prism 101, a half-wave plate 102, a Faraday rotator crystal 103, a second polarization beam splitter prism 105 and a turning prism 104 arranged in sequence. The cross section of the first polarization beam splitter prism 101 is an isosceles trapezoid with a base angle of 45°. The first polarization beam splitter prism 101 is used to input signal light, and a first polarization beam splitter film 1011 is arranged inside the first polarization beam splitter prism 101 for separating or synthesizing P-polarized light and S-polarized light in the signal light. The half-wave plate 102 and the Faraday rotator crystal 103 are bonded together to form an optical rotation mechanism, which is used to rotate the polarization of the signal light in a single transmission direction by 90°, while not performing polarization rotation on the signal light in the other transmission direction. As shown Figure 3-5As shown, in this embodiment, the polarization direction rotates 90° when the light propagates from right to left, and the polarization direction does not rotate when the light propagates from left to right. The cross section of the second polarization beam splitter prism 105 is a right-angled trapezoid with a base angle of 45°. The second polarization beam splitter prism 105 is used to output signal light, and a second polarization beam splitter film 1012 is provided inside the second polarization beam splitter prism 105 for separating or synthesizing P polarized light and S polarized light in the signal light. The cross section of the turning prism 104 is an isosceles right triangle. The turning prism 104 is used to reflect the signal light and make a 180° turn in the transmission direction of the signal light.
[0022] The lower part of the long side end face where the long base of the cross section of the first polarization beam splitter prism 101 is located is bonded to one end face of the half-wave plate 102, the upper and lower end faces where the upper and lower waist sides of the cross section of the first polarization beam splitter prism 101 are located are both provided with high reflection films, the first polarization beam splitter film 1011 is parallel to the lower end face of the first polarization beam splitter prism 101, the other end face of the half-wave plate 102 is bonded to one end face of the Faraday rotator crystal 103, the other end face of the Faraday rotator crystal 103 is bonded to the long side end face where the long base of the cross section of the second polarization beam splitter prism 105 is located, the upper end face where the oblique waist side of the cross section of the second polarization beam splitter prism 105 is located is provided with a high reflection film, the second polarization beam splitter film 1012 is parallel to the upper end face of the second polarization beam splitter prism 105, and the lower end face where the right-angle waist side of the cross section of the second polarization beam splitter prism 105 is located is bonded to the bottom face of the turning prism 104.
[0023] The circulator core has three signal ports, the first signal port Port1 is located on the upper part of the long side end face of the first polarization beam splitter prism 101, that is, the first signal port Port1 is located on the part of the long side end face that is not bonded to the half-wave plate, the second signal port Port2 is located on the short side end face where the short bottom side of the cross section of the first polarization beam splitter prism 101 is located, and the third signal port Port3 is located on the short side end face where the short bottom side of the cross section of the second polarization beam splitter prism 105 is located.
[0024] In this embodiment, all the bonding surfaces and signal port surfaces of the circulator core are provided with anti-reflection films.
[0025] In this embodiment, the angle at which the signal light enters the circulator core, that is, the angle between the incident direction of the signal light entering the first polarization beam splitter prism from the first signal port and the normal direction of the long side end face of the first polarization beam splitter prism, is 1-5°.
[0026] In other embodiments of the present invention, the positions of the half-wave plate and the Faraday rotator crystal may also be interchanged.
[0027] like Figure 3As shown, the signal light is incident from Port 1 on the upper end face of the first polarization beam splitter prism 101 and is reflected. After passing through the first polarization beam splitter film 1011, the P light in the signal light is transmitted and the S light is reflected. The P light is reflected by the lower end face of the first polarization beam splitter prism 101. After the P light and the S light pass through the half-wave plate 102 and the Faraday rotator crystal 103 respectively, the original P light is changed into S light, and the original S light is changed into P light. The rotated S light is incident on the second polarization beam splitter prism 105 and is reflected by the second polarization beam splitter film 1012. The rotated P light is incident on the second polarization beam splitter prism 105 and is reflected by the upper end face of the second polarization beam splitter prism 105 and then passes through the second polarization beam splitter film 1012. The two are combined and transmitted to the turning prism 104. The signal light is reflected twice by the turning prism 104 and is output from the bottom edge of the turning prism 104 to the second polarization beam splitter prism 105.
[0028] like Figure 4 As shown, after the signal light is transmitted to the second polarization beam splitter film 1012, the P light in the signal light is transmitted, and the S light is reflected. The P light is reflected by the upper end face of the second polarization beam splitter prism 105. After the P light and the S light pass through the Faraday rotator crystal 103 and the half-wave plate 102 respectively, the polarization directions of both remain unchanged. The P light enters the first polarization beam splitter prism 101 and passes through the first polarization beam splitter film 1011; the S light enters the first polarization beam splitter prism 101, is reflected by its lower end face, and then is reflected by the first polarization beam splitter film 1011. The P light and the S light are combined and transmitted to Port2.
[0029] like Figure 5 As shown, the signal light enters the first polarization beam splitter prism 101 from Port 2, and after passing through the first polarization beam splitter film 1011, the P light in the signal light is transmitted, and the S light is reflected. The S light is reflected by the lower end face of the first polarization beam splitter prism 101. After the P light and the S light pass through the half-wave plate 102 and the Faraday rotator crystal 103, the original P light becomes S light, and the original S light becomes P light. The rotated P light enters the second polarization beam splitter prism 105, and is transmitted by the second polarization beam splitter film 1012; the rotated S light enters the second polarization beam splitter prism 105, and is reflected by the upper end face of the second polarization beam splitter prism 105, and then is reflected by the second polarization beam splitter film 1012. The P light and the S light are combined and transmitted to Port 3.
[0030] The above is only the preferred embodiment of the utility model, and does not limit the utility model in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the utility model without departing from the technical solution of the utility model still belongs to the protection scope of the technical solution of the utility model.
Claims
1. A circulator core, characterized in that: The invention comprises a first polarization beam splitter prism, a half-wave plate, a Faraday rotator crystal, a second polarization beam splitter prism and a turning prism which are arranged in sequence; the first polarization beam splitter prism has a cross section in the form of an isosceles trapezoid with a base angle of 45°, which is used to input signal light, and a first polarization beam splitter film is arranged inside the first polarization beam splitter prism, which is used to separate or synthesize P polarized light and S polarized light in the signal light; the half-wave plate and the Faraday rotator crystal are bonded together, which are used to perform a 90° polarization rotation on the signal light in a single transmission direction, and not perform a polarization rotation on the signal light in another transmission direction; the second polarization beam splitter prism has a cross section in the form of a right-angle trapezoid with a base angle of 45°, which is used to output signal light, and a second polarization beam splitter film is arranged inside the first polarization beam splitter prism, which is used to separate or synthesize P polarized light and S polarized light in the signal light; the turning prism has a cross section in the form of an isosceles right triangle, which is used to reflect the signal light, and perform a 180° turn on the transmission direction of the signal light; The lower part of the long side end face where the long base of the cross section of the first polarization beam splitter prism is located is bonded to one end face of the half-wave plate, the upper and lower end faces where the upper and lower waist sides of the cross section of the first polarization beam splitter prism are located are both provided with high reflection films, the first polarization beam splitter film is parallel to the lower end face of the first polarization beam splitter prism, the other end face of the half-wave plate is bonded to one end face of the Faraday rotator crystal, the other end face of the Faraday rotator crystal is bonded to the long side end face where the long base of the cross section of the second polarization beam splitter prism is located, the upper end face where the oblique waist side of the cross section of the second polarization beam splitter prism is located is provided with a high reflection film, the second polarization beam splitter film is parallel to the upper end face of the second polarization beam splitter prism, and the lower end face where the right-angle waist side of the cross section of the second polarization beam splitter prism is located is bonded to the bottom face of the turning prism; The circulator core has three signal ports, the first signal port is located on the upper part of the long side end face of the first polarization beam splitter prism, the second signal port is located on the short side end face where the short bottom side of the cross section of the first polarization beam splitter prism is located, and the third signal port is located on the short side end face where the short bottom side of the cross section of the second polarization beam splitter prism is located.
2. A circulator core according to claim 1, characterized in that: The positions of the half-wave plate and the Faraday rotator crystal can be interchanged.
3. The circulator core according to claim 1, characterized in that: All the bonding surfaces and signal port surfaces of the circulator core are provided with anti-reflection films.
4. The circulator core according to claim 1, characterized in that: The angle at which the signal light enters the circulator core, that is, the angle between the incident direction of the signal light entering the first polarization beam splitter prism from the first signal port and the normal direction of the long side end face of the first polarization beam splitter prism, is 1-5°.