High repetition frequency seed laser

Abstract

The utility model relates to a high repetition frequency seed laser, which comprises a pump laser, a saturable absorber, a coupler, a gain fiber, a beam splitter, a fiber bragg grating and a 1 * M fiber optical switch, the output end of the coupler is sequentially connected with the gain fiber, the beam splitter and the fiber bragg grating, and a main resonant cavity is formed between the saturable absorber and the fiber bragg grating; the common input end of the 1 * M fiber optical switch is connected to the input end of the beam splitter, the output port of each channel of the 1 * M fiber optical switch is plated with a high reflection film, and a new branch resonant cavity is formed between the output end of each channel of the 1 * M fiber optical switch and the fiber bragg grating. The cavity length of the optical fiber branches and the cavity length of the optical fiber resonator are adjusted by adding the optical fiber optical switch, and the device has the advantages of being large in adjusting range and low in difficulty.

Description

Technical Field

[0001] The utility model relates to the technical field of lasers, in particular to a high repetition frequency seed laser. Background Art

[0002] In the prior art, the seed laser seed adjusts the fiber branch and the cavity length of the fiber resonator by mechanical means. This adjustment method has a narrow adjustment range and is difficult to adjust. Summary of the Invention

[0003] The purpose of the utility model is to overcome the deficiencies of the prior art and provide a high repetition rate seed laser.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A high repetition rate seed laser includes a pump laser, a saturable absorber, a coupler, a gain fiber, a beam splitter, a fiber Bragg grating (FBG), and a 1×M fiber optical switch. The pump laser and the saturable absorber are respectively connected to the input end of the coupler, and the output end of the coupler is sequentially connected to the gain fiber, the beam splitter, and the fiber Bragg grating (FBG). A main resonant cavity is formed between the saturable absorber and the fiber Bragg grating. The common input end of the 1×M fiber optical switch is connected to the input end of the beam splitter. The output port of each channel of the 1×M fiber optical switch is coated with a high-reflection film. New branch resonant cavities are formed between the output end of each channel of the 1×M fiber optical switch and the fiber Bragg grating.

[0006] Furthermore, the lengths of the channels of the 1×M fiber optic switch are different.

[0007] Furthermore, the saturable absorber is a saturable absorber mirror.

[0008] Furthermore, the erbium-doped fiber or ytterbium-doped fiber may also be other doped fibers with gain characteristics.

[0009] Furthermore, the present invention also includes a 1×N fiber optic switch, wherein the common input end of the 1×N fiber optic switch is connected to the input end of the coupler, and the output end of each channel of the 1×N fiber optic switch is respectively connected to the corresponding saturable absorber.

[0010] The utility model adopts the above technical solution and adjusts the fiber branch and the cavity length of the fiber resonator by adding a fiber optical switch, which has the advantages of a large adjustment range and low difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0012] Figure 1 This is a schematic diagram of Example 1 of the present utility model;

[0013] Figure 2 This is a schematic diagram of Example 2 of the present utility model. DETAILED DESCRIPTION

[0014] Example 1, as Figure 1 As shown, the high repetition rate seed laser of the present invention includes a pump laser 1, a saturable absorber 2, a coupler 3, a gain fiber 4, a beam splitter 5, a fiber Bragg grating 6 and a 1×M fiber optical switch 7. The pump laser 1 and the saturable absorber 2 are respectively connected to the input end of the coupler 3, and the output end of the coupler 3 is sequentially connected to the gain fiber 4, the beam splitter 5 and the fiber Bragg grating 6. A main resonant cavity is formed between the saturable absorber 2 and the fiber Bragg grating 6. The common input end of the 1×M fiber optical switch 7 is connected to the input end of the beam splitter 5. The output port of each channel of the 1×M fiber optical switch 7 is coated with a high reflective film. The output end of each channel of the 1×M fiber optical switch 7 forms a new branch resonant cavity with the fiber Bragg grating 6, and the length of each channel of the 1×M fiber optical switch 7 is different.

[0015] In this embodiment, the saturable absorber 2 is a saturable absorber mirror. The gain fiber 4 is an erbium-doped fiber or an ytterbium-doped fiber, or may be other doped fibers with gain characteristics.

[0016] Pump laser 1 acts as the pump source, causing the doped particles in gain fiber 4 to undergo energy level transitions and generate a new operating wavelength (for example, when pumped by 980nm pump laser 1, gain fiber 4 generates a wavelength of 1520-1570nm). The newly generated operating wavelength oscillates in the main resonant cavity.

[0017] The main resonant cavity length is m × the new branch resonant cavity length. Each channel length of the 1 × M fiber optical switch 7 is different, where m is a positive integer. Channels 1 through M of the optical switch can be selected to be L / 2, L / 3, L / 4, ..., L / M, respectively. The laser pulse repetition frequency of this embodiment is the inverse of the optical propagation time of the new branch resonant cavity.

[0018] like Figure 2 As shown, embodiment 2 adds a 1×N fiber optic switch 8 on the basis of embodiment 1. The common input end of the 1×N fiber optic switch 8 is connected to the input end of the coupler 3, and the output end of each channel of the 1×N fiber optic switch 8 is respectively connected to the corresponding saturable absorber 2.

[0019] In Example 2, the main resonant cavity length L is also variable to a finite number (N), such as L1, L2, L3, ..., LN. This provides a wider range of channel length options for a 1×M fiber optical switch, such as L1 / 2, L2 / 2, L1 / 3, L2 / 3, ..., LN / M. In other words, Example 2 simultaneously changes the cavity lengths of both the main resonant cavity and the new branch resonant cavity, further expanding the range of repetition frequencies and providing a wider range of repetition frequency options.

[0020] The above describes the specific implementation of the present invention, but 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 implementation without departing from the principle and essence of the present invention, but these changes and modifications will fall within the scope of protection of the present invention.

Claims

1. High repetition rate seed laser, characterized by: The invention comprises a pump laser, a saturable absorber, a coupler, a gain fiber, a beam splitter, a fiber Bragg grating (FBG), and a 1×M fiber optical switch. The pump laser and the saturable absorber are respectively connected to the input end of the coupler. The output end of the coupler is sequentially connected to the gain fiber, the beam splitter, and the fiber Bragg grating (FBG). A main resonant cavity is formed between the saturable absorber and the fiber Bragg grating. The common input end of the 1×M fiber optical switch is connected to the input end of the beam splitter. The output port of each channel of the 1×M fiber optical switch is coated with a high-reflection film. A new branch resonant cavity is formed between the output end of each channel of the 1×M fiber optical switch and the fiber Bragg grating.

2. The high repetition rate seed laser according to claim 1, characterized in that: The lengths of the channels of the 1×M fiber optic switch are different.

3. The high repetition rate seed laser according to claim 1, characterized in that: The saturable absorber is a saturable absorption mirror.

4. The high repetition rate seed laser according to claim 1, characterized in that: The gain optical fiber is an erbium-doped optical fiber or an ytterbium-doped optical fiber.

5. The high repetition rate seed laser according to claim 1, characterized in that: It also includes a 1×N fiber optic switch, a common input end of the 1×N fiber optic switch is connected to the input end of the coupler, and an output end of each channel of the 1×N fiber optic switch is respectively connected to a corresponding saturable absorber.

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