Signal light recovery device of fiber laser

Abstract

The utility model relates to the technical field of optical technology, in particular to a fiber laser signal light recovery device which comprises a first collimator, a first polarization splitting prism, a first optical rotation assembly, a first wave plate, a second polarization splitting prism and a second collimator which are sequentially arranged from left to right. The first polarization splitting prism, the second optical rotation assembly, the second wave plate, the third polarization splitting prism and the third collimator are sequentially arranged from top to bottom; and a fourth polarization splitting prism is arranged between the third polarization splitting prism and the second polarization splitting prism. Through reasonable arrangement of a combined structure of the optical rotation assembly, the wave plate and the polarization splitting prism, a composite function of single polarization transmission from the first collimator to the second collimator and dual polarization transmission from the second collimator to the third collimator is realized, and diversified requirements of a complex optical system are met.

Description

Technical Field

[0001] This utility model relates to the field of optical technology, specifically to a signal light recovery device for a fiber laser. Background Technology

[0002] A fiber laser signal light recovery device is an optical device that uses the Faraday rotation effect and a polarizing beam splitter to change the polarization plane of light. Its principle is to use Faraday's clockwise and counterclockwise rotations to move the incident polarized light from the input port to the common port. Because of the counterclockwise rotation of the Faraday oscillator, the common port cannot return to the input port during reverse transmission. Instead, the common port is moved to the output port due to the polarization state of the light and the refraction characteristics of the polarization plane changed by the polarizing beam splitter. This type of optical circulator has wide applications in fiber optic transmission systems, especially in polarization-maintaining fiber optic transmission systems, where its role is particularly important. With the changing needs of polarization-maintaining fiber optic transmission systems and the increasing demands on the receiving port signal, this solution adds a dual-polarized light transmission capability from the common port to the receiving port to the traditional single-polarization optical circulator.

[0003] Current technology can only produce single-polarized or dual-polarized light for fiber laser signal light recovery devices, which is insufficient to meet the current requirements for single-polarized transmission from the input port to the common port and dual-polarized transmission from the common port to the receiving port. Utility Model Content

[0004] To achieve the above objectives, this utility model provides the following technical solution: a fiber laser signal light recovery device, comprising, from left to right, a first collimator, a first polarizing beam splitter, a first optical rotation component, a first waveplate, a second polarizing beam splitter, and a second collimator; further comprising, from top to bottom, a first polarizing beam splitter, a second optical rotation component, a second waveplate, a third polarizing beam splitter, and a third collimator; a fourth polarizing beam splitter is disposed between the third polarizing beam splitter and the second polarizing beam splitter.

[0005] Furthermore, both the first and second optical rotation components include a magnetic element and a magneto-optical crystal embedded within the magnetic element; the magnetic element includes an adjustable magnetic pole structure, which includes at least two switchable magnetic pole states.

[0006] Furthermore, the optical rotation angle of the magneto-optical crystal is set to 45°.

[0007] Furthermore, both the first and second waveplates are 22.5°.

[0008] Furthermore, the internal optical path structure of the first polarizing beam splitter, the second polarizing beam splitter, the third polarizing beam splitter, and the fourth polarizing beam splitter is as follows: horizontally polarized light passes directly through the axis, and vertically polarized light is refracted internally at 90° and then exited from the side port.

[0009] Furthermore, the first collimator, the second collimator, and the third collimator are all polarization-maintaining fiber collimators.

[0010] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0011] 1. By rationally setting the combination structure of optical rotation components, waveplates and polarizing beam splitters, the composite function of single polarization transmission from the first collimator to the second collimator and dual polarization transmission from the second collimator to the third collimator is realized, meeting the diverse needs of complex optical systems;

[0012] 2. The optical rotation component adopts an adjustable magnetic pole structure, which can switch the magnetic pole state to change the optical rotation direction. With the secondary adjustment of the 22.5° waveplate, it can accurately control the change of polarization state and adapt to signal light recovery scenarios with different polarization characteristics.

[0013] 3. By employing a polarization-maintaining fiber collimator and a polarization beam splitter with a specific optical path structure, the distortion of the polarization state during transmission is reduced, ensuring the stability and accuracy of signal light recovery;

[0014] 4. By rationally arranging the spatial positions of each optical element, the device maintains a compact structure while achieving composite functions, making it easy to integrate into a miniaturized optical system. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] Figure 2 This is a schematic diagram of the optical path and polarization from the first collimator to the second collimator of this utility model;

[0017] Figure 3 This is a schematic diagram of the horizontal polarization light transmission from the second collimator to the third collimator of this utility model;

[0018] Figure 4 This is a schematic diagram of vertically polarized light transmission from the second collimator to the third collimator of this utility model.

[0019] In the figure: 101, first collimator; 102, first polarizing beam splitter; 103, first optical rotation component; 104, first waveplate; 105, second polarizing beam splitter; 106, second collimator; 107, second optical rotation component; 108, second waveplate; 109, third polarizing beam splitter; 110, fourth polarizing beam splitter; 111, third collimator. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Please see Figure 1-4 This embodiment of a fiber laser signal light recovery device comprises a core structure consisting of a horizontal optical path assembly and a vertical optical path assembly. The horizontal optical path assembly consists of a first collimator 101, a first polarizing beam splitter 102, a first optical rotation component 103, a first waveplate 104, a second polarizing beam splitter 105, and a second collimator 106 arranged sequentially from left to right. The vertical optical path assembly consists of a first polarizing beam splitter 102, a second optical rotation component 107, a second waveplate 108, a third polarizing beam splitter 109, and a third collimator 111 arranged sequentially from top to bottom. A fourth polarizing beam splitter 110 is provided between the right side of the third polarizing beam splitter 109 and the front of the second polarizing beam splitter 105. The overall structure of each component is compact, small in size, has low insertion loss, high extinction ratio, and is simple to assemble and debug.

[0022] Implementation Method 1:

[0023] This embodiment is used to realize single-polarized light transmission from the first collimator 101 to the second collimator 106. The specific structural configuration and optical path process are as follows:

[0024] The first collimator 101 is a polarization-maintaining fiber collimator, which can collimate the input linearly polarized light into a parallel beam. The first polarizing beam splitter 102 has a cubic structure. The beam output from the first collimator 101 is incident perpendicularly onto the incident surface of the first polarizing beam splitter 102. The center of the optical path is aligned with the center of the prism. The first optical rotation component 103 includes a cylindrical magnet element and a magneto-optical crystal embedded in the center of the magnet. The magnetic pole direction of the magnet element is set along the horizontal optical path axis. When a positive current is applied, a positive magnetic field is generated, causing the magneto-optical crystal to rotate the incident light clockwise by 45°. The first waveplate 104 has a rotation of 22.5°.

[0025] The second polarizing beam splitter 105 has the same structure as the first polarizing beam splitter 102. Its incident surface is parallel to the light-emitting surface of the first waveplate 104. The second collimator 106 adopts the same type of polarization-maintaining fiber collimator as the first collimator 101. Its incident surface is aligned with the light-emitting surface of the second polarizing beam splitter 105.

[0026] The optical path process in this embodiment is as follows: The 0° horizontally polarized light output from the first collimator 101 is perpendicularly incident on the first polarizing beam splitter 102. After transmission, it enters the first optical rotation component 103. Under the action of a positive magnetic field, the magneto-optical crystal rotates the polarization direction clockwise by 45° to form 45° linearly polarized light. The 45° linearly polarized light is incident on the first waveplate 104. After phase modulation by the waveplate, the polarization direction is rotated counterclockwise by 22.5°, and finally restored to 0° horizontally polarized light. The 0° horizontally polarized light passes directly through the second polarizing beam splitter 105 and is received by the second collimator 106, completing single-polarization transmission.

[0027] Implementation Method Two:

[0028] This embodiment is used to realize the horizontal polarization light transmission from the second collimator 106 to the third collimator 111. The specific structural configuration and optical path process are as follows:

[0029] The 0° horizontally polarized light output from the second collimator 106 is incident perpendicularly on the second polarizing beam splitter 105. After transmission, it enters the first waveplate 104, and the polarization direction is rotated counterclockwise by 22.5° to form 45° linearly polarized light.

[0030] Under the action of a positive magnetic field, the first optical rotation component 103 is in the same direction as the magnetic field in Embodiment 1, and generates a counterclockwise 45° optical rotation effect on the incident 45° linearly polarized light to form 90° vertically polarized light. The 90° vertically polarized light is incident on the first polarizing beam splitter 102, and after being refracted internally by 90°, it is output from the side port and enters the vertical optical path.

[0031] The structure of the second optical rotator 107 in the vertical optical path is the same as that of the first optical rotator 103. The magnetic poles of its magnet element are arranged along the axial direction of the vertical optical path. When a reverse current is passed through, a reverse magnetic field is generated, which causes the internal magneto-optical crystal to rotate the incident light counterclockwise by 45°. The second waveplate 108 adopts the same model as the first waveplate 104 with a 22.5° angle. The optical axis direction is fixed at a 45° angle with the light-emitting surface of the second optical rotator 107.

[0032] The third polarizing beam splitter 109 has the same structure as the first polarizing beam splitter 102. Its incident surface is parallel to the light-emitting surface of the second waveplate 108. The fourth polarizing beam splitter 110 is perpendicularly connected to the third polarizing beam splitter 109. Its incident surface receives the lateral output light of the third polarizing beam splitter 109. The third collimator 111 adopts the same type of polarization-maintaining fiber collimator as the first collimator 101 and is connected to the straight output end of the fourth polarizing beam splitter 110.

[0033] The optical path process in this embodiment is as follows: The 90° vertically polarized light output from the first polarizing beam splitter 102 enters the second optical rotation component 107. Under the action of the reverse magnetic field, the polarization direction rotates counterclockwise by 45° to form 45° linearly polarized light. This 45° linearly polarized light is incident on the second waveplate 108. After modulation, the polarization direction rotates counterclockwise by 22.5° to restore it to 0° horizontally polarized light. The 0° horizontally polarized light passes directly through the third polarizing beam splitter 109 and the fourth polarizing beam splitter 110, and is finally received by the third collimator 111 to complete the transmission of horizontally polarized light.

[0034] Implementation Method 3:

[0035] This embodiment is used to realize the vertical polarization light transmission from the second collimator 106 to the third collimator 111. The specific structural configuration and optical path process are as follows:

[0036] The 90° vertically polarized light output from the second collimator 106 is incident perpendicularly on the second polarizing beam splitter 105. After being refracted internally by 90°, it is output from the side port and directly incident on the fourth polarizing beam splitter 110.

[0037] The fourth polarizing beam splitter 110 refracts the incident 90° vertically polarized light at a 90° angle, causing the light path to be redirected and then incident on the third polarizing beam splitter 109. The third polarizing beam splitter 109 refracts the 90° vertically polarized light at a 90° angle again, forming a vertically downward light path.

[0038] The incident surface of the third collimator 111 is aligned with the lateral output end of the third polarizing beam splitter 109 to receive 90° vertically polarized light after two refractions.

[0039] The optical path process in this embodiment is as follows: The 90° vertically polarized light output from the second collimator 106 is refracted at 90° in the second polarizing beam splitter 105, and after changing its propagation direction, it enters the fourth polarizing beam splitter 110; after being refracted at 90° by the fourth polarizing beam splitter, the optical path direction is adjusted to be horizontal to the left, and then it is incident on the third polarizing beam splitter 109; it is refracted at 90° again in the third polarizing beam splitter 109, and the optical path direction is adjusted to be vertically downward, and finally received by the third collimator 111, completing the vertical polarization light transmission.

[0040] The above three implementation methods, through fixed structural arrangement and parameter settings, respectively realize single polarization transmission from the first collimator to the second collimator, horizontal polarization transmission from the second collimator to the third collimator, and vertical polarization transmission. During the assembly of the overall device, precision tooling is used to ensure the relative position accuracy of each component. During the debugging process, the insertion loss is reduced by adjusting the pitch angle and yaw angle of the collimator.

[0041] The entire workflow is now complete, and anything not described in detail in this specification is existing technology known to those skilled in the art.

[0042] It should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0043] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A signal light recovery device for a fiber laser, characterized in that: It includes, from left to right, a first collimator (101), a first polarizing beam splitter (102), a first optical rotation component (103), a first waveplate (104), a second polarizing beam splitter (105), and a second collimator (106); It also includes, from top to bottom, a first polarizing beam splitter (102), a second optical rotation component (107), a second waveplate (108), a third polarizing beam splitter (109), and a third collimator (111); A fourth polarizing beam splitter (110) is disposed between the third polarizing beam splitter (109) and the second polarizing beam splitter (105).

2. The fiber laser signal light recovery device according to claim 1, characterized in that: The first optical rotation component (103) and the second optical rotation component (107) both include a magnetic element and a magneto-optical crystal embedded inside the magnetic element; the magnetic element includes an adjustable magnetic pole structure, which includes at least two switchable magnetic pole states.

3. The fiber laser signal light recovery device according to claim 2, characterized in that: The optical rotation angle of the magneto-optical crystal is set to 45°.

4. The fiber laser signal light recovery device according to claim 1, characterized in that: The first waveplate (104) and the second waveplate (108) are both 22.5°.

5. The fiber laser signal light recovery device according to claim 1, characterized in that: The internal optical path structure of the first polarizing beam splitter (102), the second polarizing beam splitter (105), the third polarizing beam splitter (109), and the fourth polarizing beam splitter (110) is as follows: the horizontally polarized light passes straight through along the axial direction, and the vertically polarized light is refracted at 90° inside and then led out from the side port.

6. The fiber laser signal light recovery device according to claim 1, characterized in that: The first collimator (101), the second collimator (106), and the third collimator (111) are all polarization-maintaining fiber collimators.

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