CN205543680U - Fiber grating is as cubic solid laser of output cavity mirror - Google Patents

Abstract

The fiber grating of the utility model is used as a block solid laser of the output cavity mirror, which is composed of a pump semiconductor laser 1, a coupling optical system 2, a block solid working substance 3, a mode matching lens 4, and an optical fiber arranged in sequence from the input end to the output end. Composed of grating 5; the light emitted by the pump semiconductor laser 1 is focused by the coupling optical system 2 to the block solid working substance 3; the left end of the block solid working substance 3 is coated with the pump semiconductor laser 1. The working substance 3 emits a dielectric film with high wavelength reflection, which constitutes the total reflection mirror of the bulk solid-state laser; the mode matching lens 4 is used to realize the mode matching between the bulk solid working substance 3 and the fiber grating 5; the fiber grating 5 serves as output mirror. The laser uses a fiber grating as the output cavity mirror of the bulk solid laser, which solves the problems of bulk solid laser fiber coupling output, high gain spectral line suppression, narrow linewidth output and simple structure.

Description

A bulk solid-state laser with fiber grating as output cavity mirror

【Technical field】

The utility model relates to the field of photoelectric devices, in particular to a solid-state laser.

【Background technique】

Since the utility model, the laser has been widely researched and applied due to its advantages of good interference, monochromaticity and directivity. The output cavity mirrors of bulk solid-state lasers are generally plano-flat, plano-concave or plano-convex lenses. After the output laser is coupled into the single-mode fiber, due to the low coupling efficiency, >50% or even more power or energy is often lost. In order to obtain low-gain laser output, it is necessary to design and plate a complex film layer on the output cavity mirror to suppress the operation of high-gain laser. Although the fiber laser can be directly coupled to the output of the fiber, the output spectral line is relatively wide; in order to obtain a narrow linewidth laser output, it is necessary to add frequency-selective optical elements such as etalons and birefringent filters in the cavity, and sometimes it is necessary to use a ring cavity Inhibit space burning effect, complex structure. Fiber lasers require low temperature or even liquid nitrogen cooling to obtain low-gain laser lines, and the system is complex. In order to obtain narrow-linewidth and low-gain laser output, fiber lasers generally adopt the method of seed source amplification. Therefore, fiber coupling output, suppression of high-gain spectral lines, and narrow linewidth output technologies have become current research hotspots in the laser field.

【Content of utility model】

In order to solve the problems of fiber coupling output, high gain spectral line suppression, narrow line width output and simple structure of block solid laser, the utility model provides a block solid laser using fiber grating as output cavity mirror.

The utility model adopts the following technical scheme to construct a block solid-state laser, which consists of a pumping semiconductor laser 1, a coupling optical system 2, a block solid working substance 3, a mode matching lens 4, and a fiber grating 5 arranged in sequence from the input end to the output end. composition;

The light emitted by the pump semiconductor laser 1 is focused to the bulk solid working substance 3 through the coupling optical system 2;

The blocky solid working substance 3 is plated on its left end with a pumping semiconductor laser (1) with a highly transparent emission wavelength and a dielectric film with a high emission wavelength reflection for the blocky solid working substance (3), which constitutes a total reflection mirror of the blocky solid laser;

A mode matching lens 4 is used to realize mode matching between the bulk solid working substance 3 and the fiber grating 5;

The fiber grating 5 acts as an output cavity mirror.

Preferably, the fiber Bragg grating 5 is a single-mode single-clad or single-mode double-clad optical fiber, and a fiber Bragg grating with the emission wavelength of the bulk solid working substance 3 is written on the core of the optical fiber.

Preferably, the reflectivity of the fiber grating 5 is selected between 60% and 98% according to the emission wavelength of the bulk solid working substance 3, and the 3dB reflection bandwidth is less than 0.2nm.

Preferably, the two ends of the fiber grating 5 have a wedge angle of 8 degrees.

Preferably, the working wavelength of the pumping semiconductor laser 1 is 660nm or 793nm or 808nm or 880nm or 980nm.

Preferably, the coupling optical system 2 can be an optical fiber or a spherical lens or an aspheric lens or a prism to realize the matching between the pump light and the laser cavity mode.

Preferably, the block solid working substance 3 is a crystal material or a glass material doped with rare earth ions.

Preferably, the right end of the block solid working substance 3 is coated with an anti-reflection coating for the emission wavelength of the block solid working substance 3 .

Preferably, both ends of the mode-matching lens 4 are coated with an anti-reflection coating for the emission wavelength of the bulk solid working substance 3 .

Preferably, the mode-matching lens 4 is an aspherical lens, a spherical lens, a fixed-refractive-index lens, or a gradient-refractive-index lens.

The beneficial technical effects of the utility model are: the utility model uses the fiber grating as the output cavity mirror of the massive solid laser, and solves the problems of fiber coupling output, high gain spectral line suppression, narrow line width output and simple structure of the massive solid laser. The problems obtained; realize the direct single-mode fiber coupling output, low-gain spectral line output, and narrow linewidth laser output within the emission spectrum range of bulk solid-state lasers. The laser has low manufacturing difficulty, simple structure and stable working performance, and can be widely used in the fields of seed source of fiber amplifier, nonlinear frequency conversion, fiber optic gyroscope, fiber optic sensing and so on.

【Description of drawings】

Fig. 1 is a schematic diagram of the structural composition of a bulk solid-state laser in which a fiber grating is used as an output cavity mirror in Embodiment 1.

【detailed description】

In order to make the technical scheme and technical effect of this patent clearer, the specific implementation manner of this patent will be described in detail below in conjunction with the accompanying drawings and examples.

Embodiment one:

As shown in Figure 1, the fiber grating in this embodiment is used as the bulk solid laser of the output cavity mirror, including pumping semiconductor laser 1, coupling optical system 2, bulk solid working substance 3, mode Matching lens 4, fiber grating 5. The light emitted by the pump semiconductor laser 1 is focused to the bulk solid working substance 3 through the coupling optical system 2 .

The working wavelength of pump semiconductor laser 1 is 808nm.

The coupling optical system 2 may be an aspheric lens, which is used to realize the matching between the pump light and the laser cavity mode (the laser cavity mode refers to a stable mode formed after the laser oscillates).

The bulk solid working substance 3 is a crystal material or glass material doped with rare earth ions, which is the gain medium of the bulk solid laser, such as Nd:YVO4 crystal material, the left end is plated with a wavelength of 808nm for high transparency and a wavelength of 914nm for low gain emission The highly reflective dielectric film constitutes the total reflection mirror of the solid-state laser. The right end face is coated with an anti-reflection coating with a wavelength of 914nm, which can reduce the loss in the cavity.

The mode matching lens 4 is a constant refractive index lens (C-Lens for short). The mode matching between the bulk solid working substance 3 and the fiber grating 5 is realized. Both ends of the mode-matching lens 4 are coated with an anti-reflection coating with a wavelength of 914nm, which can reduce intracavity loss.

The fiber grating 5 is a single-mode single-clad fiber or a single-mode double-clad fiber, and a fiber Bragg grating with a wavelength of 914nm is written on the core of the fiber to form the output cavity mirror of the laser. The reflectivity of fiber Bragg grating is 98%, and the 3dB reflection bandwidth is 0.1nm. Both ends of the fiber grating 5 have a wedge angle of 8 degrees, that is, they are cut at an angle of 8 degrees, which can suppress the reflection of the self-oscillating laser end face. The fiber Bragg grating 5 is directly used as a laser cavity mirror, and its structure is a fiber structure. A part of the light is reflected by the fiber Bragg grating, and the other part of the light is coupled and output by the fiber Bragg grating, realizing the 914nm direct single-mode fiber coupling output.

The bulk solid-state laser in this embodiment, due to the characteristics of the fiber Bragg grating, has a high reflectivity for low-gain spectral lines, and completely transmits other higher-gain spectral lines, causing loss and inhibiting the effect. Therefore, low-gain spectral line output can be realized; and the reflectivity bandwidth of the fiber grating can be made very narrow, and the 3dB bandwidth can be less than 0.2nm, so narrow-linewidth laser output can be realized.

Embodiment two:

The fiber grating in this embodiment is used as a bulk solid laser output cavity mirror, and the structure is the same as that in the first embodiment.

The working wavelength of pump semiconductor laser 1 is 880nm.

The coupling optical system 2 is a spherical lens, which is used to realize the matching between the pump light and the laser cavity mode.

The blocky solid working substance 3 is Nd:YVO4 crystal material, and the left end is plated with a dielectric film with high transparency at 880nm wavelength and high reflection at 1064nm high-gain emission wavelength to form the total reflection mirror of the solid-state laser. The right end face is coated with an anti-reflection coating with a wavelength of 1064nm to reduce the loss in the cavity.

The mode matching lens 4 is a gradient index lens (abbreviation: G-Lens). The mode matching between the bulk solid working substance 3 and the fiber grating 5 is realized. Both ends of the mode-matching lens 4 are coated with an anti-reflection coating with a wavelength of 1064nm to reduce intracavity loss.

The fiber grating 5 is a single-mode single-clad fiber, and a fiber Bragg grating with a wavelength of 1064nm is written on the core of the fiber to form the output cavity mirror of the laser. The reflectivity of fiber Bragg grating is 90%, and the 3dB reflection bandwidth is 0.1nm. Both ends of the fiber grating 5 are wedged at an 8-degree angle, that is, they are cut at an 8-degree angle to suppress self-oscillating laser end-face reflection.

Embodiment three:

The fiber grating in this embodiment is used as a bulk solid laser output cavity mirror, and the structure is the same as that in the first embodiment.

The working wavelength of pump semiconductor laser 1 is 808nm.

The coupling optical system 2 can be an optical fiber or a prism to realize the matching between the pump light and the laser cavity mode.

The bulk solid working substance 3 is Nd:YAG crystal material, and the left end is plated with a dielectric film with high transparency at 808nm wavelength and high reflection at 1112nm low-gain emission wavelength to form a total reflection mirror of the solid-state laser. The right end face is coated with an anti-reflection coating with a wavelength of 1112nm to reduce the loss in the cavity.

The mode matching lens 4 is a fixed refractive index lens, which realizes mode matching between the bulk solid working substance and the fiber grating. Both ends of the mode matching lens are coated with 1112nm wavelength anti-reflection coating to reduce the loss in the cavity.

The fiber Bragg grating 5 is a single-mode single-clad fiber, and a fiber Bragg grating with a wavelength of 1112nm is written on the core of the fiber to form the output cavity mirror of the laser. The reflectivity of fiber Bragg grating is 96%, and the 3dB reflection bandwidth is 0.1nm. Both ends of the fiber grating have an 8-degree wedge angle, that is, they are cut at an 8-degree angle to suppress the reflection of the laser end face of the self-excited oscillation.

The above descriptions are only preferred embodiments of this patent, and are not intended to limit this patent. For those skilled in the art, this patent may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this patent shall be included within the scope of protection of this patent.

Claims (10)

1. A fiber grating is used as the bulk solid-state laser of the output cavity mirror, by the pumping semiconductor laser (1), the coupling optical system (2), the bulk solid working substance (3), Composed of a mode matching lens (4) and a fiber grating (5); characterized in that: The light emitted by the pump semiconductor laser (1) is focused to the bulk solid working substance (3) through the coupling optical system (2); The blocky solid working substance (3) is plated with a pump semiconductor laser (1) on its left end face, and the blocky solid working substance (3) has a dielectric film with high emission wavelength, which constitutes the total reflection of the blocky solid laser. mirror; A mode-matching lens (4), used to realize mode-matching between the bulk solid working substance (3) and the fiber grating (5); The fiber grating (5) acts as the output cavity mirror. 2. fiber grating as claimed in claim 1 is as the bulk solid laser of output cavity mirror, it is characterized in that: described fiber grating (5) is single-mode single-clad or single-mode double-clad optical fiber, the core of optical fiber A Bragg fiber grating having an emission wavelength of a bulk solid working substance (3) is written on it. 3. fiber grating as claimed in claim 2 is as the bulk solid laser of output cavity mirror, it is characterized in that: the reflectivity of described fiber grating (5) is selected at 60% according to bulk solid working substance (3) emission wavelength To 98%, the 3dB reflection bandwidth is less than 0.2nm. 4. The bulk solid-state laser with a fiber grating as an output cavity mirror according to any one of claims 1 to 3, characterized in that: both ends of the fiber grating (5) have a wedge angle of 8 degrees. 5. the fiber grating as described in any one of claim 1 to 3 bulk solid-state laser as output cavity mirror, it is characterized in that: described pumping semiconductor laser (1) operating wavelength is 660nm or 793nm or 808nm or 880nm or 980nm. 6. as any one of claim 1 to 3, the fiber grating is used as the bulk solid laser of output cavity mirror, it is characterized in that: described coupling optical system (2) is optical fiber or spherical lens or aspherical lens or prism, Matching between the pump light and the laser cavity mode is achieved. 7. as any one of claim 1 to 3 fiber grating as output cavity mirror block solid laser, characterized in that: the block solid working material (3) is a crystal material doped with rare earth ions or glass material. 8. fiber grating as claimed in claim 7 is as the block solid laser of output cavity mirror, it is characterized in that: described block solid working substance (3) right end face is plated block solid working substance (3) emission wavelength AR coating. 9. fiber grating as claimed in claim 1 is as the massive solid-state laser of output cavity mirror, it is characterized in that: described mode-matching lens (4) two end surfaces are coated with the anti-reflection of massive solid working substance (3) emission wavelength membrane. 10. The bulk solid laser with fiber grating as output cavity mirror according to claim 1, characterized in that: said mode matching lens (4) is an aspheric lens or a spherical lens or a fixed refractive index lens or a graded refractive index lens.