High-gain cavity emptying laser

Abstract

The invention relates to a high-gain cavity emptying laser, and belongs to the technical field of solid laser. Comprising an indication light source and a resonant cavity formed by two reflectors, a high-gain module, a small-hole diaphragm, an electro-optic Q-switched crystal, a lambda / 4 wave plate and a polaroid are arranged in the resonant cavity, and a first reflector, the electro-optic Q-switched crystal, the lambda / 4 wave plate, the polaroid, a first small-hole diaphragm, the high-gain module, a second small-hole diaphragm and a second reflector are sequentially arranged. The indication light source is arranged outside the resonant cavity. The laser has the beneficial effects that the laser which can still generate high-power laser output when the input power of the pump light source is relatively low is designed based on the high-gain module by utilizing a cavity dumping technology, the pump source is turned on, the delay time of the electro-optical Q-switched crystal is set, energy accumulated in the laser gain medium is released in an extremely short time, and the energy is saved. The cavity dumping laser based on the high-gain module is simple in structure, high in anti-interference capability and stable and reliable in system.

Description

Technical Field

[0001] The invention belongs to the technical field of solid lasers and relates to a high-gain cavity dumping laser. Background Art

[0002] Cavity dumping laser is an advanced laser technology that combines high power, high efficiency and short pulse characteristics. It has broad prospects in laser processing and material processing, laser radar, medicine and biomedicine, military and security fields, especially in applications that require high peak power and ultra-short pulses. Common cavity dumping lasers on the market are based on ordinary module cavity dumping lasers to achieve pulse light output, which not only has low pumping efficiency, but also poor anti-interference ability, high delay and large loss. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide a high-gain cavity dumped laser, which can still produce high-power laser output when the input power of the pump light source is relatively low, and at the same time solve the problem that the ASE is large and the ideal laser cannot be output when debugging the optical path. The present invention has a simple structure, strong anti-interference ability, and a stable and reliable system.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A high-gain cavity dumping laser, comprising:

[0006] Indicator light source;

[0007] A resonant cavity formed by two mirrors;

[0008] A high-gain module disposed inside the resonant cavity;

[0009] A first aperture diaphragm and a second aperture diaphragm are disposed inside the resonant cavity;

[0010] An electro-optical Q-switched crystal disposed inside the resonant cavity;

[0011] A λ / 4 wave plate disposed inside the resonant cavity;

[0012] A polarizer disposed inside the resonant cavity;

[0013] The indicator light source is placed outside the resonant cavity, and the reflector, electro-optical Q-switched crystal, λ / 4 wave plate, polarizer, first pinhole aperture, high gain module, second pinhole aperture, and reflector are placed inside the resonant cavity in sequence;

[0014] The electro-optic Q-switched crystal outputs from the polarizer and periodically extracts energy from the resonant cavity;

[0015] A cycle of cavity emptying is divided into two stages:

[0016] The first stage is the light field establishment stage. The pump source power supply is turned on, current is injected for pumping, the electro-optical Q-switched crystal is turned off, and the wave plate is rotated to the optimal off state. Under the action of continuous pumping by the pump source, the number of inverted particles in the working substance continues to accumulate. When the particle number inversion density in the working substance in the cavity reaches the threshold, the cavity begins to oscillate and generate laser.

[0017] The second stage is the emptying period, during which the electro-optical Q-switched crystal is turned on to change the polarization direction of the light, and the light is guided on the polarizer to be released from the cavity to generate laser.

[0018] The indicator light source has the characteristics of broadband low-coherence spectrum, stable output power, good beam quality, environmental adaptability and easy integration.

[0019] Furthermore, the high-gain module is a laser module with the function of amplifying optical signals. The pumping mode of the laser module is side pumping or end pumping. The working material is composed of doped optical fiber or solid material, and the optical signal is amplified by stimulated radiation.

[0020] Furthermore, the aperture sizes of the first pinhole aperture and the second pinhole aperture are set to 2 mm.

[0021] Furthermore, the reflector constitutes a resonant cavity required for laser output, and the type of the resonant cavity is a parallel plane cavity.

[0022] Furthermore, the polarizer is a 45° polarizer.

[0023] Furthermore, the electro-optical Q-switched crystal is in a closed state in the first stage and in an open state in the second stage.

[0024] Furthermore, the rotation angle of the λ / 4 wave plate in the first stage minimizes the laser energy output in the cavity, and the rotation angle in the second stage maximizes the laser energy output in the cavity.

[0025] Furthermore, the rotation angle of the polarizer in the first stage minimizes the laser energy output in the cavity, and the rotation angle in the second stage maximizes the laser energy output in the cavity.

[0026] Furthermore, the indicating light source is a He-Ne laser.

[0027] The beneficial effects of the present invention are as follows: based on a high-gain module and utilizing the cavity dumping technology, a laser is designed that can still generate high-power laser output when the input power of the pump light source is relatively low. The pump source is turned on, and the delay time of the electro-optical Q-switched crystal is set to release the energy accumulated in the laser gain medium in a very short time, thereby realizing a cavity dumping laser based on a high-gain module, which has a simple structure, strong anti-interference ability, and a stable and reliable system.

[0028] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0030] Figure 1 This is a principle block diagram of a high-gain cavity dumping laser of the present invention;

[0031] Figure 2 A schematic diagram of a high-gain module of the present invention;

[0032] Figure 3 It is a light field simulation distribution of a high-gain cavity dumped laser under a high-gain module of the present invention;

[0033] Figure 4 This is a schematic diagram of laser output of a high-gain cavity dumped laser of the present invention.

[0034] Reference numerals: indicate light source 1 , first reflecting mirror 2 , electro-optical Q-switched crystal 3 , λ / 4 wave plate 4 , polarizing plate 5 , first pinhole diaphragm 6 , high gain module 7 , second pinhole diaphragm 8 , second reflecting mirror 9 . DETAILED DESCRIPTION

[0035] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0036] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0037] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0038] Example 1

[0039] like Figure 1 As shown, embodiment 1 of the present invention is a high-gain cavity dumped laser, comprising an indicating light source 1, a resonant cavity composed of a first reflecting mirror 2 and a second reflecting mirror 9, wherein a high-gain module 7, a first pinhole aperture 6, a second pinhole aperture 8, an electro-optical Q-switched crystal 3, a λ / 4 wave plate 4, and a polarizer 5 are arranged inside the resonant cavity. The first reflecting mirror 2, the electro-optical Q-switched crystal 3, the λ / 4 wave plate 4, the polarizer 5, the first pinhole aperture 6, the high-gain module 7, the second pinhole aperture 8, and the second reflecting mirror 9 are placed in sequence, and the indicating light source 1 is placed outside the resonant cavity.

[0040] The present invention utilizes cavity dumping technology to output from the polarizer 5 through the electro-optical Q-switched crystal 3, and periodically extracts energy from the resonant cavity. A cavity dumping cycle is divided into two stages:

[0041] The first stage is the light field establishment stage. At this time, the pump source power supply is turned on, current is injected for pumping, the electro-optical Q-switched crystal 3 is turned off, and the wave plate 4 is rotated to the optimal off state. Under the action of continuous pumping by the pump source, the number of inverted particles in the working substance continues to accumulate. As long as the particle number inversion density in the working substance in the cavity reaches the threshold, the cavity begins to oscillate and generate laser. Since the loss in the cavity is very small, the laser is continuously generated and accumulated in the cavity under the action of continuous pumping, and the laser power in the cavity continues to grow;

[0042] The second stage is the emptying period, during which the electro-optical Q-switched crystal 3 is turned on to change the polarization direction of the light and guide the light to be released from the cavity on the polarizer 5, thereby generating a laser with high power, high efficiency and short pulse characteristics.

[0043] Based on the cavity dumping technology of the high-gain module 7, a laser is designed which can still generate high-power laser output when the input power of the pump light source is relatively low. The pump source is turned on, and the delay time of the electro-optical Q-switched crystal 3 is set to release the energy accumulated in the laser gain medium in a very short time. A cavity dumping laser based on a high-gain module is realized, which has a simple structure, strong anti-interference ability, and a stable and reliable system.

[0044] Example 2

[0045] Based on Example 1, the high-gain module 7 refers to a laser module with the function of efficiently amplifying optical signals. The pumping mode of the laser module is side pumping or end pumping; the working material is usually composed of doped optical fiber or solid material, and the optical signal is amplified by stimulated radiation. The solid material mainly includes various laser crystals including Nd:YAG crystal, Nd:KGW crystal and Nd:YVO4 crystal. The actual picture of the high-gain module required by the present invention is as follows: Figure 2 The module injects current through the upper port, and contains three LDs, which are arranged in a "pin" shape to achieve a high gain effect.

[0046] Example 3

[0047] On the basis of Example 1, a pinhole aperture is first used to collimate the indicator light source. The specific operation is: first turn on the indicator light source 1, place the pinhole aperture close to the indicator light source 1, so that its output light passes through the small hole of the pinhole aperture, then move the pinhole aperture to a far distance, and adjust the pitch and yaw of the indicator light source 1: according to the principle of coarse adjustment at a near distance and fine adjustment at a far distance, the indicator light source 1 can pass through the pinhole aperture at any place without changing the height of the pinhole aperture, and the collimation of the indicator light source is completed.

[0048] Example 4

[0049] On the basis of Example 1, the indicator light source 1 is turned on, the electro-optical Q-switched crystal 3 is turned off, the polarizer 5 is adjusted to 45°, and the light field simulation distribution under the high gain module 7 is performed, such as Figure 3As shown, the specific operation is: first add the polarizer 5 and the high-gain module 7, turn on the indicator light source 1, adjust the angle of the polarizer 5 and the position of the high-gain module 7, so that the light can hit the center of the crystal rod and the center of the polarizer 5. After the adjustment is completed, add pinhole apertures at both ends of the high-gain module 7 to limit the ASE generated by the module due to the high gain. During debugging, the input current can be reduced to target ASE, and the size of the crystal rod can be increased, thereby reducing ASE. Then add the electro-optical Q-switched crystal 3, the wave plate 4, the first reflector 2, and the second reflector 9. When adding the reflectors, they need to be adjusted. The adjustment operation is: use the light output by the indicator light source 1 to hit the second reflector 9 through the pinhole aperture, and then adjust the pitch and yaw of the second reflector 9 by observing the reflection point on the pinhole aperture so that its reflection point can pass through the pinhole aperture. Similarly, adjust the first reflector 2.

[0050] Example 5

[0051] On the basis of Example 1, the indicator light source 1 is turned off, the pump source power supply is turned on, and current is injected to start working, generate inversion particle number, adjust the position of the λ / 4 wave plate 4 to close the door to the minimum energy output, and adjust the electro-optical Q-switched crystal 3, observe the output of the pump light, adjust the pitch angle until the closing effect is optimal, then turn on the electro-optical Q-switched crystal 3, and output high-power, low-delay, short-pulse laser at the polarizer 5, such as Figure 4 shown.

[0052] Example 6

[0053] On the basis of Example 1, the first reflector 2 and the second reflector 9 form a resonant cavity required for laser output, and the resonant cavity type is a parallel plane cavity.

[0054] Example 7

[0055] On the basis of Example 1, the polarizer 5 adopts a 45° polarizer. When the polarizer 5 is adjusted to 45°, the λ / 4 wave plate 4 is rotated to the off state, and the electro-optical Q-switched crystal 3 works, the polarization direction of the light is changed by the electro-optical effect. The changed polarization direction no longer meets the passage condition of the polarizer 5. Therefore, the light is guided out of the cavity by the polarizer 5, thereby realizing cavity emptying.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A high-gain cavity dumping laser, characterized in that: include: Indicator light source; A resonant cavity formed by two mirrors; A high-gain module disposed inside the resonant cavity; A first aperture diaphragm and a second aperture diaphragm are disposed inside the resonant cavity; An electro-optical Q-switched crystal disposed inside the resonant cavity; A λ / 4 wave plate disposed inside the resonant cavity; A polarizer disposed inside the resonant cavity; The indicator light source is placed outside the resonant cavity, and the reflector, electro-optical Q-switched crystal, λ / 4 wave plate, polarizer, first pinhole aperture, high gain module, second pinhole aperture, and reflector are placed inside the resonant cavity in sequence; The output is obtained from the polarizer through an electro-optic Q-switched crystal, and energy is periodically extracted from the resonant cavity. A cycle of cavity emptying is divided into two stages: The first stage is the light field establishment stage. The pump source power supply is turned on, current is injected for pumping, the electro-optical Q-switched crystal is turned off, and the wave plate is rotated to the optimal off state. Under the action of continuous pumping by the pump source, the number of inverted particles in the working substance continues to accumulate. When the particle number inversion density in the working substance in the cavity reaches the threshold, the cavity begins to oscillate and generate laser. The second stage is the emptying period, during which the electro-optical Q-switched crystal is turned on to change the polarization direction of the light, and the light is guided on the polarizer to be released from the cavity to generate laser.

2. The high-gain cavity dumped laser according to claim 1, characterized in that: The high-gain module is a laser module with the function of amplifying optical signals. The pumping mode of the laser module is side pumping or end pumping. The working material is composed of doped optical fiber or solid material, and the optical signal is amplified by stimulated radiation.

3. The high-gain cavity dumped laser according to claim 1, characterized in that: The aperture sizes of the first aperture stop and the second aperture stop are set to 2 mm.

4. The high-gain cavity dumped laser according to claim 1, characterized in that: The reflector forms a resonant cavity required for laser output, and the type of the resonant cavity is a parallel plane cavity.

5. The high-gain cavity dumped laser according to claim 1, characterized in that: The polarizer is a 45° polarizer.

6. The high-gain cavity dumped laser according to claim 1, characterized in that: The electro-optical Q-switched crystal is in a closed state in the first stage and in an open state in the second stage.

7. The high-gain cavity dumped laser according to claim 1, characterized in that: The rotation angle of the λ / 4 wave plate in the first stage minimizes the laser energy output in the cavity, and the rotation angle in the second stage maximizes the laser energy output in the cavity.

8. The high-gain cavity dumped laser according to claim 1, characterized in that: The rotation angle of the polarizer in the first stage minimizes the laser energy output in the cavity, and the rotation angle in the second stage maximizes the laser energy output in the cavity.

9. The high-gain cavity dumped laser according to claim 1, characterized in that: The indicating light source is a He-Ne laser.

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