A multi-pass optical isolator
Patent Information
- Application Number
- CN202522660118.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-16
- Publication Date
- 2026-11-03
- Estimated Expiration
- 2035-12-16
AI Technical Summary
Existing high-power optical isolators are bulky and expensive, and the existing technology of improving isolation by connecting two or more isolators in series is not economical.
Design a multi-pass optical isolator. By adding a reflection device in the optical path, the laser beam passes through the optical rotator multiple times. The polarization direction of the laser beam is rotated by a rotating plate and a Faraday rotator, and then reflected by the reflection device, thus realizing multiple transmission of the beam.
This improved the isolation of the optical isolator, reduced its size, and lowered its cost.
Smart Images
Figure CN224934258U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of optical isolator technology, and in particular relates to a multi-channel optical isolator. Background Technology
[0002] Optical isolators are key components in laser processing systems, used to prevent back-propagating light from interfering with or damaging the light source. Isolation is an important parameter of optical isolators. Existing high-power optical isolators typically use two or more isolators connected in series to improve isolation, but this method increases size and manufacturing cost. Utility Model Content
[0003] This invention addresses the problems existing in the prior art by providing a multi-channel optical isolator.
[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a multi-pass optical isolator, comprising an input fiber collimator, a first optical beam splitter, a beam rotator, a reflector, and a second optical beam splitter. The laser emitted from the input fiber collimator enters the first optical beam splitter. The first optical beam splitter is located to the left of the beam rotator, and the beam emitted from the first optical beam splitter enters the beam rotator. The second optical beam splitter is located to the left or right of the beam rotator. There is at least one reflector, and each reflector reflects the beam emitted from the beam rotator back to the beam rotator. The last beam emitted by the beam rotator enters the second optical beam splitter.
[0005] Furthermore, when there is an odd number of reflecting devices, the second beam splitter is located on the left side of the optical rotation device; when there is an even number of reflecting devices, the second beam splitter is located on the right side of the optical rotation device.
[0006] Furthermore, when there is only one reflecting device, the reflecting device is located on the right side of the light-rotating device.
[0007] Furthermore, when the number of the reflecting devices is greater than or equal to two, the reflecting devices are distributed on the left and right sides of the optical rotation device.
[0008] Furthermore, when the number of reflecting devices is odd, the number of reflecting devices on the right side of the light-rotating device is one more than the number of reflecting devices on the left side of the light-rotating device.
[0009] Furthermore, when there is an even number of reflecting devices, the number of reflecting devices on the left and right sides of the optical rotation device is the same.
[0010] Furthermore, the optical rotation device includes a rotating plate distributed on the left and right and a Faraday rotator. The rotating plate is used to rotate the polarization direction of the laser by 45 degrees; the Faraday rotator is used to perform a non-reciprocal rotation of the polarization direction of the laser by 45 degrees.
[0011] Furthermore, each reflecting device includes a first total reflection mirror, a first polarization beam splitter, a second polarization beam splitter, and a second total reflection mirror arranged sequentially along the optical path. The first and second total reflection mirrors are used to reflect p-polarized light and s-polarized light; the first and second polarization beam splitters are used to transmit p-polarized light and reflect s-polarized light.
[0012] Furthermore, the first and second optical beam splitters are used to split light into p-polarized light and s-polarized light, or to combine p-polarized light and s-polarized light into a single beam.
[0013] Furthermore, the rotating plate is a half-wave plate.
[0014] Compared with the prior art, the present invention has the following advantages: The present invention is reasonably designed. By adding a reflection device to the optical path of the optical isolator, the laser can pass through a rotating device multiple times, which not only improves the isolation of the optical isolator, but also reduces the size of the optical isolator and lowers the cost. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the forward light transmission structure of Embodiment 1 of this utility model; Figure 2 This is a schematic diagram of the reverse light transmission structure according to Embodiment 1 of this utility model; Figure 3 This is a schematic diagram of the forward light transmission structure of Embodiment 2 of this utility model; Figure 4 This is a schematic diagram of the reverse light transmission structure in Embodiment 2 of this utility model.
[0016] In the picture: 1-Input fiber collimator; 2-First optical beam splitter; 3-Optical rotation device; 4-First reflection device; 5-Second optical beam splitter; 6-Second reflection device; 301-Rotating plate; 302-Faraday rotator; 401-First total reflection mirror; 402-First polarization beam splitter; 403-Second polarization beam splitter; 404-Second total reflection mirror; 601-First total reflection mirror A; 602-First polarization beam splitter A; 603-Second polarization beam splitter A; 604-Second total reflection mirror A. Detailed Implementation
[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0018] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0019] like Figures 1-4 As shown, this utility model discloses a multi-pass optical isolator, comprising an input fiber collimator 1, a first optical beam splitter 2, a beam rotator 3, at least one reflecting device, and a second optical beam splitter 5. The input fiber collimator 1 is located to the left of the first optical beam splitter 2 and is used to input laser light. The laser light emitted from the input fiber collimator 1 enters the first optical beam splitter 2. The first optical beam splitter 2 is located to the left of the beam rotator 3, and the beam emitted from the first optical beam splitter 2 enters the beam rotator 3. The beam rotator 3 keeps the polarization direction of the forward-passing light unchanged, while rotating the polarization direction of the reverse-passing light by 90 degrees. The second optical beam splitter 5 is located to the left or right of the beam rotator 3. The beam emitted from the beam rotator 3 first enters a reflecting device, and then each reflecting device reflects the beam emitted from the beam rotator 3 back to the beam rotator 3. After passing through all reflecting devices, the beam emitted from the beam rotator 3 for the last time enters the second optical beam splitter 5.
[0020] Specifically, when there is an odd number of reflecting devices (1, 3, 5, etc.), the second beam splitter is located on the left side of the optical rotator 3. When there is an even number of reflecting devices (2, 4, 6, etc.), the second beam splitter is located on the right side of the optical rotator.
[0021] Furthermore, when there is only one reflecting device, the reflecting device is located on the right side of the optical rotator 3, and the second optical beam splitter 5 is located on the left side of the optical rotator 3, that is: the first and second optical beam splitters are located on the same side (the left side of the optical rotator).
[0022] Furthermore, when the number of reflecting devices is two or more, the reflecting devices are distributed on the left and right sides of the optical rotation device 3, and the left and right sides are alternately distributed. Specifically: when the number of reflecting devices is odd, the number of reflecting devices on the right side of the optical rotation device 3 is one more than the number of reflecting devices on the left side. For example, when there are three reflecting devices, one reflecting device is set on the left side of the optical rotation device, and two reflecting devices are set on the right side. When the number of reflecting devices is even, the number of reflecting devices on the left and right sides of the optical rotation device is the same. For example, when there are two reflecting devices, one reflecting device is set on each of the left and right sides of the optical rotation device; when there are four reflecting devices, two reflecting devices are set on each of the left and right sides of the optical rotation device.
[0023] Specifically, the optical rotator 3 includes a rotating plate 301 distributed on the left and right, and a Faraday rotator 302. The rotating plate 301 is used to rotate the polarization direction of the laser by 45 degrees; the Faraday rotator 302 is used to perform a non-reciprocal 45-degree rotation of the polarization direction of the laser. The optical rotator 3 keeps the polarization direction of the forward-passing light unchanged, while rotating the polarization direction of the reverse-passing light by 90 degrees. Further, the rotating plate is a half-wave plate.
[0024] Specifically, each reflecting device has the same structure, including a first total reflection mirror 401, a first polarization beam splitter 402, a second polarization beam splitter 403, and a second total reflection mirror 404 arranged sequentially along the optical path. The first total reflection mirror 401 and the second total reflection mirror 404 are used to reflect p-polarized light and s-polarized light; the first polarization beam splitter 402 and the second polarization beam splitter 403 are used to transmit p-polarized light and reflect s-polarized light.
[0025] Specifically, the first optical beam splitter 2 and the second optical beam splitter 5 are used to split light into p-polarized light and s-polarized light, or to combine p-polarized light and s-polarized light into a single beam.
[0026] Example 1, taking one reflective device as an example, is a two-way optical isolator: like Figure 1 As shown, the dual-channel optical isolator includes: an input fiber collimator 1, a first optical beam splitter 2, an optical rotator 3, a first reflector 4, and a second optical beam splitter 5 arranged according to the optical path. Both the first and second optical beam splitters 2 and 5 are located to the left of the optical rotator 3, and the first reflector 4 is located to the right of the optical rotator 3. The optical rotator 3 consists of a rotating plate 301 and a Faraday rotator 302, where the rotating plate 301 is a half-wave plate. The reflector 4 consists of a first total reflection mirror 401, a first polarization beam splitter 402, a second polarization beam splitter 403, and a second total reflection mirror 404.
[0027] like Figure 1The optical path shown in the diagram, where collimated laser light (containing p-polarized and s-polarized light) emitted by fiber collimator 1 is input, is then separated and transmitted separately after passing through the first optical beam splitter 2. 1) For p-polarized light, after passing directly through the input beam splitter 2, it is incident on the rotating plate 301, where it is rotated 45° clockwise. Then it is incident on the Faraday rotator 302, where its polarization direction is rotated 45° counterclockwise, meaning the total rotation is 0°. The p-polarized light remains p-polarized. Then, the p-polarized light is incident on the first total reflection mirror 401, reflected by the first total reflection mirror 401, and then incident on the first polarization beam splitter 402. After being transmitted through the first polarization beam splitter 402, it is incident on... The light transmitted through the second polarization beam splitter 403 is incident on the second total reflection mirror 404, and after being reflected by the second total reflection mirror 404, it enters the Faraday rotator 302, where its polarization direction is rotated counterclockwise by 45°. Then it is incident on the rotating plate 301, where its polarization direction is rotated counterclockwise by 45°, for a total rotation of 90°. The p-polarized light becomes s-polarized light, and then it is incident on the second beam splitter 5. This s-polarized light is reflected by the second beam splitter 5 and then output.
[0028] 2) For s-polarized light, after being reflected by the first beam splitter 2, it is incident on the rotating plate 301, rotated 45° clockwise by the rotating plate 301, and then incident on the Faraday rotator 302. Its polarization direction is rotated 45° counterclockwise, that is, it rotates a total of 0°. The s-polarized light is still s-polarized light. Then the s-polarized light is incident on the first polarization beam splitter 402, reflected by the first polarization beam splitter 402, and then incident on the second polarization beam splitter 403. After being reflected by the second polarization beam splitter 403, it is incident on the Faraday rotator 302. Its polarization direction is rotated 45° counterclockwise, and then incident on the rotating plate 301. Its polarization direction is rotated 45° counterclockwise, that is, it rotates a total of 90°. The s-polarized light becomes p-polarized light, and then it is incident on the second beam splitter 5. This p-polarized light is transmitted by the second beam splitter 5 and then output.
[0029] Finally, after the incident laser passes through the optical rotator 3 twice, the s-polarized light reflected from the second optical beam splitter 5 and the transmitted p-polarized light are combined into a single laser beam output.
[0030] Reverse light transmission optical path, such as Figure 2 As shown, the externally input return light (containing p-polarized light and s-polarized light) is separated and transmitted separately after passing through the second optical beam splitter 5: 1) For p-polarized light, after passing directly through the second optical beam splitter 5, it is incident on the rotating plate 301, rotated 45° clockwise by the rotating plate 301, and then incident on the Faraday rotator 302. Its polarization direction is rotated 45° counterclockwise, that is, it is rotated 0° in total. The p-polarized light is still p-polarized light. Then it is incident on the second polarization beam splitter 403. Most of the p-polarized light is transmitted out by the second polarization beam splitter 403 and cannot return to the fiber collimator 1. However, due to the insufficient extinction ratio of the second polarization beamsplitter 403 (approximately 20dB), a small portion of the p-polarized light is reflected by the second polarization beamsplitter 403 and then incident on the first polarization beamsplitter 402. After being transmitted by the first polarization beamsplitter, it is incident on the first total reflection mirror 401, reflected by the first total reflection mirror 401, and then incident on the Faraday rotator 302. Its polarization direction is rotated counterclockwise by 45°, and then incident on the optical rotator 301. Its polarization direction is rotated counterclockwise by 45°, that is, it is rotated a total of 90°. The p-polarized light becomes s-polarized light, and then incident on the first optical beamsplitter 2. This s-polarized light is reflected by the first optical beamsplitter 2 and cannot return to the fiber collimator 1, thus achieving isolation of the p-polarized light.
[0031] 2) For s-polarized light, after being reflected by the second beam splitter 5, it is incident on the rotating plate 301, rotated 45° clockwise by the rotating plate 301, and then incident on the Faraday rotator 302. Its polarization direction is rotated 45° counterclockwise, that is, it is rotated 0° in total. The s-polarized light is still s-polarized light. Then it is incident on the second total reflection mirror 404. After being reflected by the second total reflection mirror 404, it is incident on the second polarization beam splitter 403. Most of the s-polarized light is reflected out by the second polarization beam splitter 403 and cannot return to the fiber collimator 1. However, due to the insufficient extinction ratio of the second polarization beamsplitter 403 (approximately 20dB), a small portion of the s-polarized light is transmitted through the second polarization beamsplitter 403 and then incident on the first polarization beamsplitter 402. After being reflected by the first polarization beamsplitter 402, it is incident on the Faraday rotator 302, where its polarization direction is rotated counterclockwise by 45°. Then, it is incident on the optical rotator 301, where its polarization direction is rotated counterclockwise by 45°. In total, it is rotated by 90°, and the s-polarized light becomes p-polarized light. Then, it is incident on the first optical beamsplitter 2, where the p-polarized light is transmitted out and cannot return to the fiber collimator 1, thus achieving isolation of the s-polarized light.
[0032] Example 2, taking two reflective devices as an example (the two reflective devices are the first reflective device 4 and the second reflective device 6), is a three-way optical isolator: like Figure 3 and Figure 4As shown, the three-way optical isolator includes: an input fiber collimator 1, a first optical beam splitter 2, an optical rotator 3, a first reflector 4, a second optical beam splitter 5, and a second reflector 6 arranged according to the optical path. The first optical beam splitter 2 and the second reflector 6 are located to the left of the optical rotator 3, and the first reflector 4 and the second optical beam splitter 5 are located to the right of the optical rotator 3. The second reflector 6 consists of a first total reflection mirror A601, a first polarization beam splitter A602, a second polarization beam splitter A603, and a second total reflection mirror A604.
[0033] The difference between Example 2 and Example 1 is that: (1) A second reflecting device 6 is placed on the left side of the optical rotating device 3; (2) The second beam splitter 5 is placed on the right side of the optical rotating device; (3) The laser passes through the optical rotating device 3 3 times. The more times it passes through, the higher the isolation.
[0034] The forward and reverse light paths of Embodiment 2 are similar to those of Embodiment 1. However, Embodiment 2 increases the number of reflection devices, thereby increasing the number of times the light beam passes through the optical rotating device. This will not be repeated here.
[0035] This invention improves the isolation of the optical isolator by adding a reflection device to the optical path of the optical isolator, allowing the laser to pass through a single optical rotating device multiple times (the more times it passes through, the higher the isolation). This not only improves the isolation of the optical isolator but also reduces its size and lowers the cost.
[0036] If this utility model discloses or relates to mutually fixedly connected parts or structural components, then, unless otherwise stated, a fixed connection can be understood as: a detachable fixed connection (e.g., using bolts or screws), or a non-detachable fixed connection (e.g., riveting, welding). Of course, mutually fixed connections can also be replaced by an integral structure (e.g., manufactured using a casting process) (except where it is obviously impossible to use an integral forming process).
[0037] In addition, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in this utility model above include states or shapes that are similar to, close to, or approximate with them.
[0038] Any component provided by this utility model can be assembled from multiple individual components, or it can be a single component manufactured by a one-piece molding process.
[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it; although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this utility model or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the technical solution claimed by this utility model.
Claims
1. A multi-channel optical isolator, characterized in that: The system includes an input fiber collimator, a first optical beam splitter, a beam rotator, a reflector, and a second optical beam splitter. The laser beam emitted from the input fiber collimator enters the first optical beam splitter. The first optical beam splitter is located to the left of the beam rotator, and the beam emitted from the first optical beam splitter enters the beam rotator. The second optical beam splitter is located to the left or right of the beam rotator. At least one reflector is used, and each reflector reflects the beam emitted from the beam rotator back to the beam rotator. The last beam emitted by the beam rotator enters the second optical beam splitter.
2. The multi-channel optical isolator according to claim 1, characterized in that: When there is an odd number of reflecting devices, the second beam splitter is located on the left side of the optical rotation device; when there is an even number of reflecting devices, the second beam splitter is located on the right side of the optical rotation device.
3. A multi-channel optical isolator according to claim 2, characterized in that: When there is only one reflecting device, the reflecting device is located on the right side of the optical rotation device.
4. A multi-channel optical isolator according to claim 2, characterized in that: When the number of the reflecting devices is greater than or equal to two, the reflecting devices are distributed on the left and right sides of the optical rotation device.
5. A multi-channel optical isolator according to claim 4, characterized in that: When the number of reflecting devices is odd, the number of reflecting devices on the right side of the optical rotation device is one more than the number of reflecting devices on the left side of the optical rotation device.
6. A multi-channel optical isolator according to claim 4, characterized in that: When there is an even number of reflecting devices, the number of reflecting devices on the left and right sides of the optical rotation device is the same.
7. A multi-channel optical isolator according to claim 1, characterized in that: The optical rotation device includes a rotating plate distributed on the left and right and a Faraday rotator. The rotating plate is used to rotate the polarization direction of the laser by 45 degrees; the Faraday rotator is used to perform a non-reciprocal rotation of the polarization direction of the laser by 45 degrees.
8. A multi-channel optical isolator according to claim 1, characterized in that: Each reflecting device includes a first total reflection mirror, a first polarizing beam splitter, a second polarizing beam splitter, and a second total reflection mirror arranged sequentially along the optical path. The first and second total reflection mirrors are used to reflect p-polarized light and s-polarized light; the first and second polarizing beam splitters are used to transmit p-polarized light and reflect s-polarized light.
9. A multi-channel optical isolator according to claim 1, characterized in that: The first and second optical beam splitters are used to split light into p-polarized light and s-polarized light, or to combine p-polarized light and s-polarized light into a single beam.
10. A multi-channel optical isolator according to claim 7, characterized in that: The rotating plate is a half-wave plate.