CN111969402A - Intermediate infrared narrow linewidth solid pulse laser applied to trolley and method - Google Patents

Abstract

The present disclosure provides a mid-infrared narrow linewidth solid pulse laser applied to a trolley, comprising: a laser, a coupling lens group, a plano-concave mirror, a laser crystal and a volume Bragg reflection grating arranged in sequence, and the plano-concave mirror has a set The acousto-optic crystal and the output mirror are arranged in sequence along the optical path after the concave reflection of the plano-concave mirror; it solves the current problems of unstable pulse, low power, and few miniaturized equipment, which greatly limit its application field, and Using this setting can effectively reduce the size requirements of the laser crystal, meet the requirements of deploying solid-state pulse lasers on small AVG trolleys, and obtain short-pulse laser output with low repetition frequency, high energy and narrow linewidth. The acousto-optic crystal has stable performance and sustainable Obtain stable pulsed laser output.

Description

A mid-infrared narrow linewidth solid-state pulse laser applied to a car and its method

technical field

The present disclosure belongs to the field of laser technology, and in particular relates to a mid-infrared narrow linewidth pulse laser based on acousto-optic crystals and volume Bragg reflection gratings.

Background technique

The mid-infrared laser with a wavelength of 2.8 μm is located near the "atmospheric window" and the strong absorption peak of water molecules, and has important application prospects in the fields of environmental trace gas monitoring, medical treatment and space detection. In recent years, mid-infrared solid-state laser technology based on rare-earth crystals has been rapidly developed. Laser diodes (LDs) directly pump mid-infrared lasers of rare-earth doped crystals, eliminating the need for intermediate frequency conversion, with simple structure and high beam quality. It has the advantages of high efficiency and high conversion efficiency, and is an important technical means to achieve high-efficiency and high-power 2.8μm laser output.

In recent years, the laser light source in the mid-infrared band has been attracted by the huge demand, which motivates the continuous development of mid-infrared pulsed laser technology towards full curing, miniaturization, high power, and long wavelength. At present, the pulse is unstable, the power is low, and the miniaturized equipment is few, which greatly limits its application field.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, the present disclosure provides a laser and a method for obtaining a mid-infrared pulsed laser with high energy and narrow linewidth, and realizing the operation of the mid-infrared pulsed laser with low repetition frequency, high energy and narrow linewidth.

In a first aspect, the present disclosure provides a mid-infrared narrow linewidth solid-state pulsed laser applied to a trolley, comprising: a laser, a coupling lens group, a plano-concave mirror, a laser crystal, and a volume Bragg reflection grating arranged in sequence, the plano-concave The mirror has a set inclination angle, and the acousto-optic crystal and the output mirror are sequentially arranged along the optical path reflected by the concave surface of the plano-concave mirror.

In a second aspect, the present disclosure also provides a method for using a mid-infrared narrow linewidth solid-state pulsed laser applied to a trolley as described in the first aspect, including:

The laser generates continuous laser, which is focused into the laser crystal after passing through the coupling lens group and the plano-concave mirror;

The laser crystal emits the continuous laser light to the volume Bragg reflection grating, and then returns the continuous laser light to the laser crystal through the reflection of the Bragg grating; the laser crystal increases the continuous laser light and emits it to the concave surface of the plano-concave mirror, and then reflects through the concave surface of the plano-concave mirror. reach the acousto-optic crystal;

The acousto-optic crystal emits the continuous laser to the output mirror, and the output mirror outputs the mid-infrared pulsed laser with narrow linewidth.

Compared with the prior art, the present disclosure has the following beneficial effects:

1. The present disclosure adopts a plano-concave mirror with a set inclination angle so that the continuous laser can pass through the laser crystal twice, so that the gain of the obtained laser crystal meets the requirements of the narrow line width in the mid-infrared, and solves the problem that the current pulse is unstable and the power is low. There are few miniaturized equipment, which greatly limits the problem of its application field, and the use of this setting can effectively reduce the size requirements for the laser crystal, meet the requirements of the small AVG trolley to install the solid-state pulse laser, and obtain low repetition frequency, high energy, high energy and low frequency. Short pulse laser output with narrow linewidth, stable performance of acousto-optic crystal, and stable pulse laser output can be obtained continuously.

2. In the present disclosure, by precisely adjusting the angle of the volume Bragg reflection grating, the laser output with narrow line width can also be realized, and the short pulse laser output with low repetition frequency, high energy and narrow line width can be obtained.

Description of drawings

The accompanying drawings that form a part of the present application are used to provide further understanding of the present application, and the schematic embodiments and descriptions of the present application are used to explain the present application and do not constitute improper limitations on the present application.

1 is a schematic structural diagram of a mid-infrared narrow linewidth solid-state pulse laser applied to a trolley of the present disclosure;

Among them, 1, semiconductor laser; 2, coupling lens group; 3, plano-concave mirror; 4, laser crystal; 5, volume Bragg reflection grating; 6, acousto-optic crystal; 7, output mirror.

Detailed ways:

The present disclosure will be further described below with reference to the accompanying drawings and embodiments.

It should be noted that the following detailed description is exemplary and intended to provide further explanation of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It should be noted that the terminology used herein is for the purpose of describing specific embodiments only, and is not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural as well, furthermore, it is to be understood that when the terms "comprising" and/or "including" are used in this specification, it indicates that There are features, steps, operations, devices, components and/or combinations thereof.

Example 1

As shown in FIG. 1 , the present disclosure provides a mid-infrared narrow linewidth solid-state pulsed laser applied to a trolley, comprising: a laser, a coupling lens group, a plano-concave mirror, a laser crystal and a volume Bragg reflection grating arranged in sequence. The plano-concave mirror has a set inclination angle, and the acousto-optic crystal and the output mirror are sequentially arranged along the optical path reflected by the concave surface of the plano-concave mirror.

Further, the plane of the plano-concave mirror faces the laser, and the plane is coated with an anti-reflection film.

Further, the concave surface of the plano-concave mirror faces the laser crystal, and the concave surface is coated with an anti-reflection film and a high-reflection film.

Further, the coupling lens group is located between the laser and the plano-concave mirror, the coupling lens group includes two coupling lenses arranged at a distance, and the coupling lenses are coated with an anti-reflection film. Specifically, the coupling lens group is located between the conductor laser and the plano-concave mirror, the lens of the coupling lens group is coated with a 976nm anti-reflection coating, the plane-concave mirror is coated with a 976nm anti-reflection coating, and the concave surface is coated with a 976nm anti-reflection coating and a 2.7-2.95 nm anti-reflection coating. μm high reflective film.

Further, the set inclination angle of the plano-concave mirror is an angle of 5°-45° relative to the laser light path of the laser, and the preferred angle is 15°. The angle setting of the plano-concave mirror enables the continuous laser to pass through two Sub-laser crystal, so that the gain of the obtained laser crystal meets the requirements of narrow line width in the mid-infrared, and this setting can effectively reduce the size requirements for the laser crystal, meet the requirements of solid pulse lasers on small AVG trolleys, and obtain low repetition frequency , High energy, narrow linewidth short pulse laser output.

Further, both sides of the laser crystal are coated with anti-reflection films. Specifically, the laser substrate is an Er:CaF2-SrF2 laser crystal, and both sides of the Er:CaF2-SrF2 laser crystal are coated with 976nm and 2.7-2.95μm. Antireflection coating.

Further, the volume Bragg reflection grating is coated with a high reflection film. Specifically, the volume Bragg reflection grating is coated with a high reflection film of 2.8-3.0 μm, and the scribe line is 450/mm.

Further, both sides of the acousto-optic crystal are coated with anti-reflection films. Specifically, both sides of the acousto-optic crystal are coated with an anti-reflection film of 2.8-3.0 μm.

Further, one side of the output mirror cavity is coated with a reflective film. Specifically, the output mirror is a flat output mirror, and one side of the flat output mirror cavity is coated with a reflective film with a transmittance of 2% to 2.7-3.0 μm.

Further, the laser is a fiber-coupled semiconductor laser, and the continuous laser center wavelength of the fiber-coupled semiconductor laser is 976 nm.

Specifically, as shown in FIG. 1 , the present disclosure is a mid-infrared narrow linewidth solid pulse laser applied to an AGV car, comprising a fiber-coupled semiconductor laser 1, a coupling lens group 2, a plano-concave mirror 3, a laser crystal 4, Volume Bragg reflection grating 5 , acousto-optic crystal 6 and output mirror 7 . The fiber-coupled semiconductor laser 1 generates continuous laser light. After passing through the coupling lens group 2, the continuous laser light passes through the plano-concave mirror 3 and is focused into the Er:CaF2-SrF2 laser crystal 4, and then reflected by the volume Bragg reflection grating 5. Returning, through the Er:CaF2-SrF2 crystal 4 gain, after being reflected by the plano-concave mirror 3, it reaches the acousto-optic crystal switch 6, and finally outputs the mid-infrared pulse laser with narrow linewidth through the output mirror 7 with a certain transmittance.

Example 2

The present disclosure also provides a method for using the mid-infrared narrow-linewidth solid-state pulsed laser applied to a trolley as described in the foregoing embodiments, including:

The laser generates continuous laser, which is focused into the laser crystal after passing through the coupling lens group and the plano-concave mirror;

The laser crystal emits the continuous laser light to the volume Bragg reflection grating, and then returns the continuous laser light to the laser crystal through the reflection of the Bragg grating; the laser crystal increases the continuous laser light and emits it to the concave surface of the plano-concave mirror, and then reflects through the concave surface of the plano-concave mirror. reach the acousto-optic crystal;

The acousto-optic crystal emits the continuous laser to the output mirror, and the output mirror outputs the mid-infrared pulsed laser with narrow linewidth.

Specifically, a fiber-coupled semiconductor laser generates a continuous laser. After passing through the coupling lens, the continuous laser passes through a plano-concave mirror and focuses into the Er:CaF2-SrF2 laser crystal, and then returns to the original path after being reflected by the volume Bragg reflection grating. The Er:CaF2-SrF2 crystal gain is reflected by a plano-concave mirror and reaches the acousto-optic crystal switch, and finally outputs a mid-infrared pulsed laser with a narrow linewidth through an output mirror with a certain transmittance.

Although the specific embodiments of the present disclosure have been described above in conjunction with the accompanying drawings, they do not limit the protection scope of the present disclosure. Those skilled in the art should understand that on the basis of the technical solutions of the present disclosure, those skilled in the art do not need to pay creative efforts. Various modifications or variations that can be made are still within the protection scope of the present disclosure.

Claims (10)

1. a mid-infrared narrow linewidth solid pulse laser applied to a trolley is characterized in that, comprising: a laser, a coupling lens group, a plano-concave mirror, a laser crystal and a volume Bragg reflection grating arranged in turn, and the plano-concave mirror has The inclination angle is set, and the acousto-optic crystal and the output mirror are arranged in sequence along the optical path reflected by the concave surface of the plano-concave mirror. 2 . The mid-infrared narrow linewidth solid-state pulse laser according to claim 1 , wherein the plane of the plano-concave mirror faces the laser, and the plane is coated with an anti-reflection film. 3 . 3 . The mid-infrared narrow linewidth solid-state pulse laser according to claim 1 , wherein the concave surface of the plano-concave mirror faces the laser crystal, and the concave surface is coated with an antireflection film and a high reflection film. 4 . 4. The mid-infrared narrow linewidth solid-state pulse laser of claim 1, wherein the coupling lens group is located between the laser and the plano-concave mirror, the coupling lens group comprises two coupling lenses arranged at intervals, and the coupling lens is coated With anti-reflection coating. 5 . The mid-infrared narrow linewidth solid-state pulse laser of claim 1 , wherein both sides of the laser crystal are coated with antireflection films. 6 . 6 . The mid-infrared narrow linewidth solid-state pulsed laser of claim 1 , wherein the volume Bragg reflection grating is coated with a high-reflection film. 7 . 7 . The mid-infrared narrow linewidth solid-state pulsed laser of claim 1 , wherein both sides of the acousto-optic crystal are coated with an antireflection film. 8 . 8 . The mid-infrared narrow linewidth solid-state pulse laser according to claim 1 , wherein one side of the output mirror cavity is coated with a reflective film. 9 . 9 . The mid-infrared narrow linewidth solid-state pulse laser of claim 1 , wherein the laser is a fiber-coupled semiconductor laser. 10 . 10. A method of using a mid-infrared narrow linewidth solid-state pulsed laser applied to a trolley as described in any one of claims 1-9, comprising: The laser generates continuous laser, which is focused into the laser crystal after passing through the coupling lens group and the plano-concave mirror; The laser crystal emits the continuous laser light to the volume Bragg reflection grating, and then returns the continuous laser light to the laser crystal through the reflection of the Bragg grating; the laser crystal increases the continuous laser light and emits it to the concave surface of the plano-concave mirror, and then reflects through the concave surface of the plano-concave mirror. reach the acousto-optic crystal; The acousto-optic crystal emits the continuous laser to the output mirror, and the output mirror outputs the mid-infrared pulsed laser with narrow linewidth.

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