An integrated module for a polarization-independent optical circulator and filter.
By integrating modular design and combining the first and second corner prisms and filters, the problems of large area occupation and high superposition loss of traditional optical circulators and filters are solved, and the optical path is compact, and the stability and reliability are improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- FUJIAN HITRONICS TECH INC
- Filing Date
- 2025-06-23
- Publication Date
- 2026-05-26
AI Technical Summary
Traditional discrete optical circulators and filters occupy a large area, have high superposition losses and high costs, and are also sensitive to angles, making it difficult to meet the packaging requirements of 800G/1.6T high-speed optical modules.
An integrated module of polarization-independent optical circulator and filter is adopted. By combining the first, second and third collimators and circulator core, and utilizing the cooperation of the first and second corner prisms, filters and collimators, the number of optical components is reduced, the angle sensitivity is reduced, and the stability and reliability are improved.
This achieves a compact optical path layout, reduces the number of optical components, lowers angular additional coupling loss, and improves the stability and reliability of product assembly and use.
Smart Images
Figure CN224287290U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of optical fiber communication technology, specifically to an integrated module for a polarization-independent optical circulator and filter. Background Technology
[0002] The 800G / 1.6T high-speed optical module needs to solve the problems of signal crosstalk and insertion loss. Traditional discrete components (such as optical circulators + filters) occupy a large area, which makes it difficult to meet packaging requirements, resulting in high superposition loss and high cost. At present, the circulator function is mainly realized by the traditional PBS + Faraday rotation combination, and the filter function is realized by the large-angle Z-block and multiple single fiber collimators. However, when the reflective surface of the Z-block changes, the transmission direction angle of the signal light will change by a factor of two, which has an angle sensitivity problem. At the same time, the use of a single collimator increases the number of components and the assembly steps become more complicated. Summary of the Invention
[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide an integrated module for a polarization-independent optical circulator and filter.
[0004] To achieve the above objectives, the present invention adopts the following technical solution:
[0005] An integrated module for a polarization-independent optical circulator and filter includes a first collimator, a circulator core, a second collimator, and a third collimator.
[0006] The second collimator is a dual-fiber collimator, connected to Port1-1 and Port1-2 of the integrated module. Port1-1 is used to input short-wavelength signal light, and Port1-2 is used to input long-wavelength signal light. The second collimator is used to collimate the signal light. The angle between the collimated signal light at Port1-1 and Port1-2 is 2A.
[0007] The first collimator is a single-fiber collimator, connected to the Port2 port of the integrated module, used to couple the signal light output from Port1-1 and Prot1-2 via the circulator core to the Port2 port and output it;
[0008] The third collimator is a dual-fiber collimator, connected to Port3-1 and Port3-2 of the integrated module. Port3-1 is used to receive short-wavelength signal light, Port3-2 is used to receive long-wavelength signal light, and the third collimator is used to receive collimated signal light. The angle between the collimated signal light from Port3-1 and Port3-2 is also 2A, where angle A is less than 10 degrees.
[0009] The circulator core includes a first polarizing prism, a half-wave plate, a Faraday rotator crystal, a second polarizing beam splitter, a first filter, a first corner prism, a second filter, a second corner prism, and a magnetic block;
[0010] The magnetic block is used to provide a magnetic field, enabling the Faraday rotator crystal to rotate the polarization direction of the input light under the magnetic field;
[0011] The first polarizing beam splitter has a trapezoidal cross-section and a first polarizing beam splitting film inside.
[0012] The cross-section of the second polarizing beam splitter is trapezoidal, and a second polarizing beam splitter film is provided inside it, with a high-reflection film at the bottom.
[0013] The right end face of the first polarizing beam splitter is attached to the left end face of the Faraday rotator crystal, and the first polarizing beam splitter film is parallel to the lower end face of the first polarizing beam splitter; the left end face of the second polarizing beam splitter is attached to the right end face of the half-wave plate, and the second polarizing beam splitter film is parallel to the upper end face of the second polarizing beam splitter.
[0014] The first filter and the first corner prism are located on the upper right side of the second polarizing beam splitter, and the second filter and the second corner prism are located on the lower right side of the second polarizing beam splitter.
[0015] The first filter and the second filter reflect long-wavelength signal light and transmit short-wavelength signal light. Their incident angle is B, and the value of angle B ranges from 5 to 15 degrees.
[0016] The inclined surface of the first corner prism is coated with a high-reflection film. Its apex angle is C, and the two base angles are equal to (180-C) / 2, which causes the incident angle and direction of the signal light from Port1-2 output by the first collimator to be deflected, so that the deflected signal light is incident on the first filter at an angle B. The value of angle C is in the range of 89~93 degrees.
[0017] The inclined surface of the second corner prism is coated with a high-reflection film. Its apex angle is C, and the two base angles are equal to (180-C) / 2. This causes the long-wave portion of the signal light output from the third collimator to be deflected in angle and direction after being reflected by the second filter and then passing through the second corner prism. This causes the deflected signal light to be coupled to the second collimator Port3-2 port at an angle B.
[0018] Furthermore, the positions of the half-wave plate and the Faraday rotator crystal can be interchanged.
[0019] Furthermore, the refractive index of the materials of the first and second corner prisms ranges from 1.44 to 2.0.
[0020] The present invention adopts the above technical solution and has the following beneficial effects:
[0021] By employing a first corner prism, a second corner prism, a first filter, a second filter, and a first collimator and a second collimator in combination, the number of collimators required is reduced. The use of the first and second corner prisms ensures that the angle of the signal light emitted from the corner prism remains unchanged even when the angle of the corner prism changes during actual assembly and use, reducing angular coupling loss and improving the stability and reliability of assembly and use. This design results in a more compact optical path layout, reduces the number of required optical components, and simultaneously improves the reliability and stability of the product. Attached Figure Description
[0022] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:
[0023] Figure 1 This is a simplified front view of the implementation structure of the polarization-independent optical circulator and filter integrated module of this utility model;
[0024] Figure 2 A schematic diagram showing the angles of the output light from the second and third collimators;
[0025] Figure 3 A simplified structural diagram of the circulator core;
[0026] Figure 4 This is a schematic diagram of the structure and optical path of the first filter and the first corner prism;
[0027] Figure 5 This is a schematic diagram of the structure and optical path of the second filter and the second corner prism. Detailed Implementation
[0028] like Figure 1-5 As shown, the polarization-free optical circulator and filter integrated module of this utility model includes: a first collimator 101, a circulator core 102, a second collimator 103, and a third collimator 104.
[0029] The second collimator 103 is a dual-fiber collimator, connected to Port1-1 and Port1-2 of the integrated module. Port1-1 is used to input short-wavelength signal light, and Port1-2 is used to input long-wavelength signal light. The second collimator 103 is used to collimate the signal light. The angle between the signal light from Port1-1 and Port1-2 is 2Δ. The third collimator 104 is also a dual-fiber collimator, connected to Port3-1 and Port3-2 of the integrated module. Port3-1 is used to receive short-wavelength signal light, and Port3-2 is used to receive long-wavelength signal light. The angle between the signal light from Port3-1 and Port3-2 is also 2Δ. In this embodiment, angle Δ is 6.78°.
[0030] The first collimator 101 is a single-fiber collimator connected to the Port2 port of the integrated module. It is used to collimate the signal light output from the Port1-1 port and the Port1-2 port through the circulator core 102 and couple it to the Port2 port for output.
[0031] The circulator core 102 includes a first polarizing beam splitter 1021, a Faraday rotator crystal 1022, a half-wave plate 1023, a second polarizing beam splitter 1024, a first filter 1025, a first corner prism 1026, a second filter 1027, a second corner prism 1028, and a magnetic block 1029. The magnetic block 1029 provides a magnetic field, enabling the Faraday rotator crystal 1022 to rotate the polarization direction of the input light under the magnetic field. The first polarizing beam splitter 1021 has a trapezoidal cross-section and contains a first polarizing beam splitting film. The second polarizing beam splitter 1024 has a trapezoidal cross-section and contains a second polarizing beam splitting film, with a high-reflection film at the bottom. The first polarizing beam splitter 1021 and the second polarizing beam splitter 1024 are used to input or output collimated parallel light; the first polarizing beam splitter film and the second polarizing beam splitter film are used to separate or combine P-polarized light and S-polarized light in the signal light; the high-reflection film of the second polarizing beam splitter 1024 is used to reflect the signal light; the half-wave plate 1023, the Faraday rotator crystal 1022, and the magnetic block 1029 constitute an optical rotation combination for focusing on a single transmission direction (…). Figure 3 The signal light (from left to right) is polarized and rotated by 90°, while the signal light in the opposite direction (…) Figure 3 The signal light transmitted from right to left (in the middle) does not undergo polarization rotation.
[0032] The right side of the Faraday rotator crystal 1022 is attached to the left end face of the half-wave plate 1023; the right end face of the first polarizing beam splitter 1021 is attached to the left end face of the Faraday rotator crystal 1022, and the end face of the first polarizing beam splitter film is parallel to the lower end face of the first polarizing beam splitter 1021; the left end face of the second polarizing beam splitter 1024 is attached to the right end face of the half-wave plate 1023, and the second polarizing beam splitter film is parallel to the upper end face of the second polarizing beam splitter 1024; the first filter 1025 and the first reflector 1026 are located on the upper right side of the second polarizing beam splitter 1024, and the second filter 1027 and the second reflector 1028 are located on the lower right side of the second polarizing beam splitter 1024. The first filter 1025 and the second filter 1027 reflect long-wavelength signal light and transmit short-wavelength signal light.
[0033] Figure 4This diagram illustrates the structure and optical path of the second collimator 103, the first filter 1025, and the first corner prism 1026. The short-wavelength signal light output from Port 1-1 of the second collimator 103 is horizontally output to the first filter 1025 at an angle of B, resulting in transmission. The long-wavelength signal light output from Port 1-2 of the second collimator 103 is horizontally upward at an angle 2A to the first corner prism. After reflection by the corner prism, it is horizontally downward at an angle 2B to the first filter for reflection. The long-wavelength and short-wavelength signal lights are combined into a single beam. In this embodiment, angle B = 8°, angle C = 91.2°, and both the first and second corner prisms are made of glass with a refractive index n = 1.5.
[0034] Figure 5 The diagram shows the structure and optical path of the third collimator 104, the second filter 1027, and the second corner prism 1028. The light output from Port2 passes through the first polarizing beam splitter, the optical rotation assembly, and the second polarizing beam splitter before being output horizontally. The horizontally output light is incident on the second filter 1027. The short-wavelength signal is transmitted through the second filter 1027 and transmitted to Port3-1 of the third collimator. The long-wavelength signal is reflected at the second filter 1027 and transmitted horizontally downward at an angle of 2B to the second corner prism 1028. After being reflected by the second corner prism 1028, it is transmitted horizontally upward at an angle of 2A to Port3-2 of the third collimator 104, thus achieving beam splitting and coupling of the long-wavelength and short-wavelength signal light to the third collimator 104.
[0035] The second collimator 103 outputs shortwave and longwave signal light respectively from its Port1-1 and Port1-2 ports at an angle of 2A. Figure 4 The structure shown combines the signal light into a single beam, which is then incident on the right end face of the first polarizing beam splitter 1021, where it is refracted and then transmitted to the first polarizing beam splitter film. The P-component of the signal light is transmitted through the first polarizing beam splitter, and then its polarization direction changes after passing through the optical rotation combination composed of the Faraday rotator crystal 1022 and the half-wave plate 1023. The P-component becomes the S-component, which then enters the second polarizing beam splitter 1024 and is reflected by the second polarizing beam splitter. It is then transmitted to the lower end face of the second polarizing beam splitter 1024. The S-component of the signal light is reflected after passing through the first polarizing beam splitter, and then its polarization direction changes after passing through the optical rotation combination composed of the Faraday rotator crystal and the half-wave plate. The S-component becomes the P-component, which then enters the second polarizing beam splitter 1024 and is reflected by the upper end face of the second polarizing beam splitter 1024. It is then transmitted to the second polarizing beam splitter of the second polarizing beam splitter 1024 and transmitted to the lower end face. Finally, the P-component and S-component are combined at the lower end face of the second polarizing beam splitter 1024.
[0036] The signal light, after being combined at the lower end face of the second polarizing beam splitter 1024, is reflected by the high-reflection film and transmitted upward to the second polarizing beam splitter film. The P-beam in the signal light is transmitted through the polarizing beam splitter film of the second polarizing beam splitter 1024, and is reflected at the upper end face of the second polarizing beam splitter 1024 before being output. After passing through the half-wave plate 1023 and the Faraday rotator crystal 1022, the polarization direction remains unchanged. The P-beam is incident on the first polarizing beam splitter 1021, transmitted through the first polarizing beam splitter film, and then output from the first polarizing beam splitter 1021. The S-beam in the signal beam is reflected and output after passing through the polarization beam splitter of the second polarization beam splitter 1024; after passing through the half-wave plate 1023 and the Faraday rotator crystal 1022, the polarization direction remains unchanged; the S-beam is incident on the lower end face of the first polarization beam splitter 1021 and reflected, and then incident on the first polarization beam splitter film and reflected, and output from the first polarization beam splitter 1021; the output P-beam and S-beam are combined and transmitted to the left to the first collimator 101, and finally reach the signal Port2 port.
[0037] Similarly, the light output from Port2 via the first collimator 101, after passing through the first polarizing beam splitter 1021, the Faraday rotator crystal 1022, the half-wave plate 1023, and the second polarizing beam splitter 1024, will be transmitted to the right. The signal light transmitted to the right then... Figure 5 With the structure shown, the short-wavelength signal light is transmitted through the second filter 1027 to the Port3-1 port of the third collimator 104, and the long-wavelength signal light is reflected by the second filter 1027 and then reflected by the second corner prism to the Port3-2 port of the third collimator 104.
[0038] The specific embodiments of this utility model have been described above. However, those skilled in the art should understand that this is only an example. Those skilled in the art can make various changes or modifications to this embodiment without departing from the principle and essence of this utility model, but all such changes and modifications fall within the protection scope of this utility model.
Claims
1. An integrated module for a polarization-independent optical circulator and filter, characterized in that: It includes a first collimator, a circulator core, a second collimator, and a third collimator; The second collimator is a dual-fiber collimator, connected to Port1-1 and Port1-2 of the integrated module. Port1-1 is used to input short-wavelength signal light, and Port1-2 is used to input long-wavelength signal light. The second collimator is used to collimate the signal light. The angle between the collimated signal light at Port1-1 and Port1-2 is 2A. The first collimator is a single-fiber collimator, connected to the Port2 port of the integrated module, used to couple the signal light output from Port1-1 and Prot1-2 via the circulator core to the Port2 port and output it; The third collimator is a dual-fiber collimator, connected to Port3-1 and Port3-2 of the integrated module. Port3-1 is used to receive short-wavelength signal light, Port3-2 is used to receive long-wavelength signal light, and the third collimator is used to receive collimated signal light. The angle between the collimated signal light from Port3-1 and Port3-2 is also 2A, where angle A is less than 10 degrees. The circulator core includes a first polarizing beam splitter prism, a half-wave plate, a Faraday rotator crystal, a second polarizing beam splitter prism, a first filter, a first corner prism, a second filter, a second corner prism, and a magnetic block; The magnetic block is used to provide a magnetic field, enabling the Faraday rotator crystal to rotate the polarization direction of the input light under the magnetic field; The first polarizing beam splitter has a trapezoidal cross-section and a first polarizing beam splitting film inside. The cross-section of the second polarizing beam splitter is trapezoidal, and a second polarizing beam splitter film is provided inside it, with a high-reflection film at the bottom. The right end face of the first polarizing beam splitter is attached to the left end face of the Faraday rotator crystal, and the first polarizing beam splitter film is parallel to the lower end face of the first polarizing beam splitter; the left end face of the second polarizing beam splitter is attached to the right end face of the half-wave plate, and the second polarizing beam splitter film is parallel to the upper end face of the second polarizing beam splitter. The first filter and the first corner prism are located on the upper right side of the second polarizing beam splitter, and the second filter and the second corner prism are located on the lower right side of the second polarizing beam splitter. The first filter and the second filter reflect long-wavelength signal light and transmit short-wavelength signal light. Their incident angle is B, and the value of angle B ranges from 5 to 15 degrees. The inclined surface of the first corner prism is coated with a high-reflection film. Its apex angle is C, and the two base angles are equal to (180-C) / 2, which causes the incident angle and direction of the signal light from Port1-2 output by the first collimator to be deflected, so that the deflected signal light is incident on the first filter at an angle B. The value of angle C is in the range of 89~93 degrees. The inclined surface of the second corner prism is coated with a high-reflection film. Its apex angle is C, and the two base angles are equal to (180-C) / 2. This causes the long-wave portion of the signal light output from the third collimator to be deflected in angle and direction after being reflected by the second filter and then passing through the second corner prism. This causes the deflected signal light to be coupled to the second collimator Port3-2 port at an angle B.
2. The integrated module of polarization-independent optical circulator and filter according to claim 1, characterized in that: The positions of the half-wave plate and the Faraday rotator crystal can be interchanged.
3. The integrated module of polarization-independent optical circulator and filter according to claim 1, characterized in that: The refractive index of the materials of the first and second corner prisms ranges from 1.44 to 2.0.