Femtosecond laser seed source and laser

Abstract

The invention is suitable for the technical field of laser devices, and provides a femtosecond laser seed source and a laser device, and the femtosecond laser seed source comprises a total reflection mirror with dispersion, which is provided with a first chirp mirror; a wavelength division multiplexer; the coupler is connected to the total reflection mirror with dispersion; the doped optical fiber is connected to one side, far away from the total reflection mirror with dispersion, of the coupler and is connected to the wavelength division multiplexer; the polarization maintaining optical fiber is connected to the wavelength division multiplexer; the reflective phase shifter with dispersion is provided with a second chirp mirror, and the reflective phase shifter with dispersion is connected to the polarization maintaining optical fiber and one side, far away from the total reflection mirror with dispersion, of the coupler; and the pumping source is connected to the wavelength division multiplexer. The femtosecond laser seed source provided by the embodiment of the invention can realize low-threshold mode locking.

Description

Technical Field

[0001] This application belongs to the technical field of lasers, and more specifically, relates to a femtosecond laser seed source and a laser. Background Art

[0002] Compared with traditional solid-state lasers, fiber lasers have advantages such as being spatially compact, relatively stable, and conducive to heat dissipation. The femtosecond laser seed source is an important part of the fiber femtosecond laser. The current passive mode-locking methods of the femtosecond laser seed source mainly include true saturable absorber mode-locking based on the saturable absorption characteristics of materials, nonlinear polarization rotation, and nonlinear amplifying loop mirror. The nonlinear amplifying loop mirror uses the Kerr effect of the fiber itself to achieve mode-locking. The mode-locking state generated by this mode-locking method is relatively stable and the core device is not easily damaged, becoming a research hotspot in science and industry in recent years. However, the current femtosecond laser seed source requires a very high mode-locking threshold to start. Summary of the Invention

[0003] The embodiments of this application provide a femtosecond laser seed source and a laser, which can achieve low-threshold mode-locking.

[0004] In a first aspect, the embodiments of this application provide a femtosecond laser seed source, including:

[0005] A total reflection mirror with dispersion, having a first chirped mirror;

[0006] A wavelength division multiplexer;

[0007] A coupler, connected to the total reflection mirror with dispersion;

[0008] A doped fiber, connected to the side of the coupler far from the total reflection mirror with dispersion, and connected to the wavelength division multiplexer;

[0009] A polarization-maintaining fiber, connected to the wavelength division multiplexer;

[0010] A reflective phase shifter with dispersion, having a second chirped mirror, and the reflective phase shifter with dispersion is connected to the polarization-maintaining fiber and the side of the coupler far from the total reflection mirror with dispersion;

[0011] A pump source, connected to the wavelength division multiplexer.

[0012] In some possible implementation manners of the first aspect, the second chirped mirror is a 0° chirped mirror;

[0013] The reflective phase shifter with dispersion further includes:

[0014] A first fiber collimator;

[0015] A polarization beam splitting prism is disposed on one side of the first fiber collimator to receive light from the first fiber collimator;

[0016] A Faraday rotator is disposed on one side of the polarization beam splitting prism to receive light from the polarization beam splitting prism;

[0017] An eighth - wavelength wave plate is disposed between the Faraday rotator and the second chirped mirror;

[0018] A second fiber collimator is disposed on one side of the polarization beam splitting prism to transmit light to the polarization beam splitting prism.

[0019] In some possible embodiments of the first aspect, the dispersive reflective phase shifter further includes:

[0020] A phase shifter encapsulation housing encapsulates the first fiber collimator, the polarization beam splitting prism, the Faraday rotator, the eighth - wavelength wave plate, the second chirped mirror, and the second fiber collimator.

[0021] In some possible embodiments of the first aspect, the first chirped mirror is a 0° chirped mirror;

[0022] The dispersive total - reflection mirror further includes:

[0023] A third fiber collimator, and the first chirped mirror is disposed on one side of the third fiber collimator.

[0024] In some possible embodiments of the first aspect, the dispersive total - reflection mirror further includes:

[0025] A mirror encapsulation housing encapsulates the third fiber collimator and the first chirped mirror.

[0026] In some possible embodiments of the first aspect, the dispersive total - reflection mirror is a dispersive fiber total - reflection mirror.

[0027] In some possible embodiments of the first aspect, the doped fiber is ytterbium - doped fiber.

[0028] In some possible embodiments of the first aspect, the first chirped mirror is a 0° chirped mirror.

[0029] In some possible embodiments of the first aspect, the second chirped mirror is a 0° chirped mirror.

[0030] In some possible embodiments of the first aspect, the polarization - maintaining fiber includes single - mode polarization - maintaining fiber or multi - mode polarization - maintaining fiber.

[0031] In some possible embodiments of the first aspect, the femtosecond laser seed source further includes:

[0032] A pump protector is connected to the wavelength division multiplexer and the pump source.

[0033] In a second aspect, an embodiment of the present application provides a laser, including the femtosecond laser seed source described in any one of the above.

[0034] The beneficial effects of the embodiments of the present application are as follows:

[0035] The total reflection mirror with dispersion has a first chirped mirror, and the reflective phase shifter with dispersion has a second chirped mirror. The dispersion can be controlled by the first chirped mirror and the second chirped mirror, net zero dispersion can be achieved, the mode-locking threshold can be reduced, and low-threshold mode-locking can be achieved. Description of the Drawings

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0037] Figure 1 It is a schematic structural diagram of a femtosecond laser seed source provided by an embodiment of the present application;

[0038] Figure 2 It is a schematic structural diagram of a total reflection mirror with dispersion of a femtosecond laser seed source provided by an embodiment of the present application;

[0039] Figure 3 It is a schematic structural diagram of a reflective phase shifter with dispersion of a femtosecond laser seed source provided by an embodiment of the present application. Detailed Embodiments

[0040] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer, the following further describes the present application in detail with reference to the Figures 1 to 3 drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0041] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0042] It should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0043] It should be understood that the term "and / or" used in the description and claims of the present application refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0044] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically defined.

[0045] An embodiment of the present application provides a femtosecond laser seed source, which can be applied to a femtosecond laser.

[0046] Figure 1 It is a schematic structural diagram of the femtosecond laser seed source provided by an embodiment of the present application. Figure 2 It is a schematic structural diagram of the dispersion-containing total reflection mirror of the femtosecond laser seed source provided by an embodiment of the present application. Figure 3 It is a schematic structural diagram of the dispersion-containing reflective phase shifter of the femtosecond laser seed source provided by an embodiment of the present application. Refer to Figures 1 to 3 An embodiment of the present application provides a femtosecond laser seed source including a dispersion-containing total reflection mirror 1, a coupler 2, a doped optical fiber 3, a wavelength division multiplexer 4, a polarization-maintaining optical fiber 5, a dispersion-containing reflective phase shifter 6, and a pump source 8.

[0047] The dispersion-containing total reflection mirror 1 has a first chirped mirror 11. The dispersion-containing total reflection mirror 1 can be a dispersion-containing fiber total reflection mirror or other dispersion-containing total reflection mirrors.

[0048] The first chirped mirror 11 is used to reflect light. The first chirped mirror 11 can specifically be a 0° chirped mirror, which can achieve 0° angle total reflection of light. Of course, according to actual needs, the first chirped mirror 11 can also be a chirped mirror with other reflection angles.

[0049] The coupler 2 is connected to the dispersion-containing total reflection mirror 1.

[0050] The doped optical fiber 3 is connected to one side of the coupler 2 away from the dispersion-containing total reflection mirror 1. The doped optical fiber 3 is also connected to the wavelength division multiplexer 4 to receive the light multiplexed by the wavelength division multiplexer 4.

[0051] The doped optical fiber 3 can specifically be a ytterbium-doped optical fiber, an erbium-doped optical fiber, or a neodymium-doped optical fiber.

[0052] The wavelength division multiplexer 4 is used to combine multiple optical signals with different wavelengths into one optical fiber for transmission.

[0053] The polarization-maintaining optical fiber 5 is connected to the wavelength division multiplexer 4. The polarization-maintaining optical fiber 5 can specifically be a single-mode polarization-maintaining optical fiber or a multi-mode polarization-maintaining optical fiber. Among them, the single-mode polarization-maintaining optical fiber can reduce the optical loss when used in cooperation with the wavelength division multiplexer 4.

[0054] The dispersion-containing reflective phase shifter 6 has a second chirped mirror 61.

[0055] The second chirped mirror 61 is used to reflect light. The second chirped mirror 61 can specifically be a 0° chirped mirror, which can achieve 0° angle total reflection of light. Of course, according to actual needs, the second chirped mirror 61 can also be a chirped mirror with other reflection angles.

[0056] The dispersion-containing reflective phase shifter 6 is connected to one side of the polarization-maintaining optical fiber 5 and the coupler 2 away from the dispersion-containing total reflection mirror 1.

[0057] The coupler 2, the doped optical fiber 3, the wavelength division multiplexer 4, the polarization-maintaining optical fiber 5, and the dispersion-containing reflective phase shifter 6 are connected in sequence to form an annular structure.

[0058] The pump source 8 is connected to the wavelength division multiplexer 4.

[0059] The pump of the pump source 8 enters the wavelength division multiplexer 4 and then generates laser light at the doped optical fiber 3. The generated laser light enters the dispersion-containing optical fiber total reflection mirror 1 through the coupler 2. After the laser light is reflected with additional dispersion by the dispersion-containing optical fiber total reflection mirror 1, it is divided into two beams of light by the coupler 2: one beam of light enters the doped optical fiber 3, is amplified, and then passes through the wavelength division multiplexer 4, the polarization-maintaining optical fiber 5, and the dispersion-containing reflective phase shifter 6 with additional dispersion and phase shift amount and then enters the coupler 2; the other beam of light enters the dispersion-containing reflective phase shifter 6 with additional dispersion and phase shift amount and then passes through the polarization-maintaining optical fiber 5, the wavelength division multiplexer 4, and the doped optical fiber 3 after being amplified and enters the coupler 2. The two beams of light with different directions interfere in the coupler 2, thereby realizing mode locking.

[0060] According to the above content, the dispersion-containing total reflection mirror 1 has a first chirped mirror 11, and the dispersion-containing reflective phase shifter 6 has a second chirped mirror 61. By means of the first chirped mirror 11 and the second chirped mirror 61, the dispersion can be controlled, the net zero dispersion can be achieved, the mode locking threshold can be reduced, the low-threshold mode locking can be realized, and the device can be protected.

[0061] Reference Figure 1 Moreover, the above-mentioned femtosecond laser seed source may further include a pump protector 7.

[0062] The pump protector 7 is connected to the wavelength division multiplexer 4 and the pump source 8, and can protect the pump source 8.

[0063] Specifically, the pump of the pump source 8 enters the wavelength division multiplexer 4 through the pump protector 7, and laser is generated at the doped optical fiber 3.

[0064] Reference Figure 2 Moreover, the above-mentioned all-reflective mirror 1 with dispersion may further include a third fiber collimator 13.

[0065] The first chirped mirror 11 is a 0° chirped mirror.

[0066] Since the first chirped mirror 11 is a 0° chirped mirror, the first chirped mirror 11 can be disposed on one side of the third fiber collimator 13 to reflect the light from the third fiber collimator 13. Specifically, the light reaches the first chirped mirror 11 (i.e., the 0° chirped mirror) from the third fiber collimator 13, additional dispersion is added, and then it is reflected back to the third fiber collimator 13.

[0067] Reference Figure 2 Moreover, the above-mentioned all-reflective mirror 1 with dispersion may further include a mirror encapsulation housing 15.

[0068] The mirror encapsulation housing 15 encapsulates the first chirped mirror 11 and the third fiber collimator 13.

[0069] Reference Figure 3 Moreover, the above-mentioned reflective phase shifter 6 with dispersion may further include a first fiber collimator 62, a polarization beam splitter prism 63, a Faraday rotator 64, a quarter-wave plate 65, and a second fiber collimator 66.

[0070] The second chirped mirror 61 is a 0° chirped mirror.

[0071] The first fiber collimator 62 is used to convert the transmitted light into collimated light.

[0072] The polarization beam splitter prism 63 is disposed on one side of the first fiber collimator 62 to receive the light from the first fiber collimator 62.

[0073] The Faraday rotator 64 is disposed on one side of the polarization beam splitter prism 63 to receive the light from the polarization beam splitter prism 63.

[0074] The quarter-wave plate 65 is a λ / 8 wave plate. The quarter-wave plate 65 is disposed between the Faraday rotator 64 and the second chirped mirror 61.

[0075] The second fiber collimator 66 is used to convert the transmitted light into collimated light. The second fiber collimator 66 is disposed on one side of the polarization beam splitter prism 63 to transmit light to the polarization beam splitter prism 63.

[0076] When light enters the polarization beam splitter prism 63 from the first fiber collimator 62, it reaches the Faraday rotator 64, and the polarization direction rotates by 45°. After passing through the quarter-wave plate 65, the light reaches the second chirped mirror 61 (i.e., the 0° chirped mirror). After additional dispersion, it is reflected to the quarter-wave plate 65. After passing through the quarter-wave plate 65 twice with an additional phase shift of π / 2, it passes through the Faraday rotator 64, and the polarization direction changes by 90°. After passing through the polarization beam splitter prism 63, the light reaches the second fiber collimator 66; when light enters the polarization beam splitter prism 63 from the second fiber collimator 66, it reaches the Faraday rotator 64, and the polarization direction rotates by 45°. After passing through the quarter-wave plate 65, the light reaches the second chirped mirror 61 (i.e., the 0° chirped mirror). After additional dispersion, it is reflected to the quarter-wave plate 65. After passing through the quarter-wave plate 65 twice with an additional phase shift of π / 2, it passes through the Faraday rotator 64, and the polarization direction changes by 90°. After passing through the polarization beam splitter prism 63, the light reaches the first fiber collimator 62.

[0077] Reference Figure 3 , the above-mentioned reflective phase shifter 6 with dispersion may further include a phase shifter encapsulation housing 67.

[0078] The phase shifter encapsulation housing 67 encapsulates the second chirped mirror 61, the first fiber collimator 62, the polarization beam splitter prism 63, the Faraday rotator 64, the quarter-wave plate 65, and the second fiber collimator 66.

[0079] The femtosecond laser seed source provided by the embodiment of the present application is a nonlinear ring mirror. By encapsulating the first chirped mirror 11 (i.e., the 0° chirped mirror) inside the all-reflective mirror 1 with dispersion and encapsulating the second chirped mirror 61 (i.e., the 0° chirped mirror) inside the reflective phase shifter 6 with dispersion for nonlinear ring mirror mode locking, it can not only achieve low-threshold mode locking of the all-fiber nonlinear ring mirror and realize a lower mode-locking threshold start, but also avoid the influence of the external environment, can avoid mode unlocking caused by strong mechanical vibration, and can ensure the stability of all-fiber nonlinear mode locking.

[0080] The embodiment of the present application also provides a laser, and this laser includes the femtosecond laser seed source provided by any of the above embodiments. This laser may specifically be a femtosecond laser.

[0081] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A femtosecond laser seed source, characterized in that: include: A total reflection mirror with dispersion, having a first chirped mirror; Wavelength division multiplexer; A coupler connected to the total reflection mirror with dispersion; A doped optical fiber connected to a side of the coupler away from the total reflection mirror with dispersion, and connected to the wavelength division multiplexer; A polarization-maintaining optical fiber connected to the wavelength division multiplexer; A reflective phase shifter with dispersion, having a second chirped mirror, wherein the reflective phase shifter with dispersion is connected to the polarization-maintaining optical fiber and the side of the coupler away from the total reflection mirror with dispersion; A pump source is connected to the wavelength division multiplexer.

2. The femtosecond laser seed source according to claim 1, characterized in that: The second chirped mirror is a 0° chirped mirror; The reflective phase shifter with dispersion also includes: a first optical fiber collimator; a polarization beam splitter prism, disposed on one side of the first optical fiber collimator to receive light from the first optical fiber collimator; A Faraday rotator, disposed on one side of the polarization beam splitter prism to receive light from the polarization beam splitter prism; An eighth wavelength wave plate is disposed between the Faraday rotator and the second chirped mirror; The second optical fiber collimator is arranged at one side of the polarization beam splitter prism to transmit light to the polarization beam splitter prism.

3. The femtosecond laser seed source according to claim 2, characterized in that: The reflective phase shifter with dispersion also includes: The phase shifter packaging shell encapsulates the first optical fiber collimator, the polarization beam splitter, the Faraday rotator, the eighth wavelength wave plate, the second chirped mirror, and the second optical fiber collimator.

4. The femtosecond laser seed source according to claim 1, characterized in that: The first chirped mirror is a 0° chirped mirror; The total reflection mirror with dispersion also includes: A third optical fiber collimator, wherein the first chirped mirror is arranged on one side of the third optical fiber collimator.

5. The femtosecond laser seed source according to claim 4, characterized in that: The total reflection mirror with dispersion also includes: The reflector packaging shell encapsulates the third optical fiber collimator and the first chirped mirror.

6. The femtosecond laser seed source according to claim 1, characterized in that: The total reflection mirror with dispersion is a fiber total reflection mirror with dispersion.

7. The femtosecond laser seed source according to claim 1, characterized in that: The doped optical fiber is an ytterbium-doped optical fiber, the first chirped mirror is a 0° chirped mirror, and the second chirped mirror is a 0° chirped mirror.

8. The femtosecond laser seed source according to claim 1, characterized in that: The polarization-maintaining optical fiber includes a single-mode polarization-maintaining optical fiber or a multi-mode polarization-maintaining optical fiber.

9. The femtosecond laser seed source according to any one of claims 1 to 8, characterized in that: The femtosecond laser seed source also includes: A pump protector is connected to the wavelength division multiplexer and the pump source.

10. A laser, characterized in that: Comprising the femtosecond laser seed source as claimed in any one of claims 1 to 9.

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