CN201821001U - Solid laser of diode pumping batten - Google Patents

Abstract

The utility model relates to a diode-pumped slab solid-state laser, which comprises a gain module, an input mirror and an output mirror. The gain module includes a diode array composed of multiple laser diodes, a focusing mirror, a condenser cover, a slab-shaped gain medium and a heat sink. The upper end of the condensing cover is provided with a light inlet, and covers a large surface of the strip-shaped gain medium; the other large surface of the strip-shaped gain medium is closely connected with the heat sink, and a set of opposite sides of the strip-shaped gain medium The surface is polished and coated with anti-reflection coating, as the light-transmitting surface of oscillating light or amplified light; the input mirror and output mirror are respectively located on both sides of the slab gain module, and the slab-shaped gain medium is coated with anti-reflection coating The two side surfaces of the opposite sides form a resonant cavity. The utility model has a simple structure, can realize laser output with medium and high power and high beam quality, and can be better applied in occasions where the output power requirement is not too high.

Description

Diode-pumped slab solid-state laser

technical field

The utility model relates to a diode-pumped slab solid-state laser, which belongs to the field of solid-state lasers.

Background technique

Slab laser is an important way to obtain high power and high beam quality laser output. According to different pumping methods, slab lasers are divided into three structures: end-pumped, side-pumped, and large-area-pumped. In view of the geometrical characteristics of the slab-shaped gain medium (thickness is much smaller than the dimensions of the other two directions), using two larger surfaces as cooling surfaces can obtain a good cooling effect, and can efficiently transfer waste heat to achieve high-power laser output. In order to realize the separation of the light-passing surface and the cooling surface, the end-face or side pumping method is often used. However, the area of the end face and side is small, which is not conducive to the injection of high pump light power. At the same time, due to the exponential absorption of the pump light by the gain medium, the thermal effect near the end face of the gain medium is relatively serious, which is not conducive to the power upgrade of the laser. .

On the other hand, for large-area pumped slab laser devices, water cooling is generally used, that is, water is passed through the pumping surface at the same time to cool the laser gain medium. This not only makes the structure of the device complex, but also easily causes contamination of the pump surface during long-term operation, thus reducing the efficiency and life of the device.

Utility model content

The purpose of the utility model is to propose a conduction-cooled slab laser device pumped by a diode large area. The laser has a simple structure and can realize laser output with medium and high power and high beam quality.

The purpose of this utility model is achieved through the following technical solutions.

A diode-pumped slab solid-state laser provided by the utility model includes a gain module, an input mirror and an output mirror. Wherein, the gain module includes a diode array composed of multiple laser diodes, a focusing mirror, a condenser cover, a strip-shaped gain medium and a heat sink. Wherein, the upper end of the condensing cover is provided with a light inlet, and covers a large surface of the slab-shaped gain medium; the other large surface of the slab-shaped gain medium is closely connected with the heat sink, and a large surface of the slab-shaped gain medium The opposite side surfaces of the group are polished and coated with anti-reflection coatings, which are used as the light-transmitting surface of the oscillating light or the amplified light; the input mirror and the output mirror are respectively located on both sides of the slab gain module, and are connected to the slab-shaped gain medium The two side surfaces coated with the anti-reflection coating face each other to form a resonant cavity.

According to the above structure, after the pump light emitted by the diode array is focused by the focusing lens, it enters the light collecting cavity composed of the light collecting cover and the slab-shaped gain medium through the light inlet at the upper end of the light-condensing cover, and enters the slab-shaped gain medium. The activated ions in the slab-shaped gain medium are excited to the upper energy level to form a population inversion. When the gain is greater than the loss, an oscillating laser is formed between the input mirror and the output mirror and output from the output mirror side. Moreover, the pump light that has not been absorbed after passing through the gain medium back and forth can enter the gain medium again through the reflection of the condenser cover, which improves the utilization rate of the pump light and reduces the return of the unabsorbed pump light. to the laser diode causing the probability of damage to the laser diode.

Wherein, the focusing mirror is a cylindrical lens, a cylindrical lens group or a concave cylindrical mirror, and is used for converging the pump light emitted by the diode array into the light collecting cavity.

The condensing cover can be in the shape of an arch, a rectangle, or the like.

The lower surface of the strip-shaped gain medium is connected to the heat sink by metal sealing or optical glue bonding.

The slab-shaped gain medium is laser crystal or laser ceramic, with a thickness of 0.5-3 mm, a width of 10-100 mm, and a length of 10-100 mm.

The heat sink is also connected with cooling devices such as an air cooling device, a circulating water cooling device or a semiconductor refrigerator.

The input mirror is a concave mirror or a concave cylindrical mirror, and the output mirror is a convex cylindrical mirror, forming a positive confocal unstable cavity on the plane where the slab-shaped gain medium is located.

The input mirror is a concave mirror, the output mirror is a concave mirror, and a negative branch confocal unstable cavity is formed on the plane where the strip-shaped gain medium is located.

Beneficial effect

The utility model has a simple structure and adopts a large surface of the slab-shaped gain medium as the cooling surface. The large-surface heat conduction cooling method can obtain a better cooling effect, and at the same time, the pumping method of the large-surface pump can reduce the thermal effect of the gain medium. Influence and increase the distribution area of the pump light, so as to inject more pump power. Combined with the resonator mirror, the laser oscillator and amplifier can be formed, and the laser output with medium and high power and high beam quality can be realized.

Moreover, since the structure of the gain medium is not directly cooled by the cooling liquid, the requirements for sealing are not high, and the complexity of the structure is greatly reduced. Level) occasions, cost savings, the effect can also be guaranteed.

Description of drawings

Fig. 1 is the structural representation of diode-pumped slab solid-state laser in embodiment 1;

Fig. 2 is the structural representation of diode-pumped slab solid-state laser in embodiment 2;

Fig. 3 is the structural representation of diode-pumped slab solid-state laser in embodiment 3;

FIG. 4 is a partial cross-sectional schematic diagram of a gain module of a diode-pumped slab solid-state laser in Embodiment 1;

FIG. 5 is a schematic partial cross-sectional view of a gain module of a diode-pumped slab solid-state laser in Embodiment 2 and Embodiment 3;

Fig. 6 is the structural diagram of the resonant cavity forming the diode-pumped positive branch hybrid cavity slab laser oscillator;

Fig. 7 is the structural diagram of the resonant cavity forming the diode-pumped negative-branch hybrid cavity slab laser oscillator;

Fig. 8 is the structural diagram of the resonant cavity forming a diode-pumped flat-concave stable cavity slab laser oscillator;

Fig. 9 is a structure diagram of a resonant cavity forming a diode-pumped slab hybrid cavity laser amplifier;

In the figure, 1-diode array, 2-focusing mirror, 3-condensing cover, 5-strip gain medium, 6-heat sink, 7-input mirror, 8-output mirror, 9-seed light, 10- Amplify the light.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the content in the utility model is described further.

Example 1

Referring to FIG. 1 and FIG. 4 , the diode-pumped slab solid-state laser includes a gain module, an input mirror 7 and an output mirror 8 . The gain module includes a diode array 1 composed of multiple laser diodes, a focusing mirror 2 , a condenser cover 3 , a slab-shaped gain medium 5 and a heat sink 6 . A group of opposite side surfaces of the slab-shaped gain medium 5 are polished and coated with an anti-reflection coating for the oscillating laser or the amplified light, serving as a light-transmitting surface for the laser or the amplified light. The lower surface of the slab-shaped gain medium 5 is gold-plated and sealed with the heat sink 6. The condenser cover 3 is placed on the upper surface of the slab-shaped gain medium 5, as shown in FIG. The pump light enters the gain medium again after being reflected by the condenser, which improves the utilization rate of the pump light and prevents the laser diode from being damaged due to the unabsorbed pump light returning to the laser diode. The upper end of the condenser 3 The processing has a light inlet. The input mirror 7 and the output mirror 8 are located on both sides of the slab gain module, and are opposite to the two side surfaces of the slab-shaped gain medium 5 coated with an anti-reflection film, forming a resonant cavity. The heat sink 6 is connected with the circulating water cooling device. Focusing lens 2 selects plano-convex cylindrical lens for use.

The pumping light emitted by the diode array 1 is focused by the focusing lens 2, and then enters the condenser cavity composed of the condenser cover 3 and the slab-shaped gain medium 5 through the light inlet at the upper end of the condensing cover 3, and enters the slab-shaped gain medium 5. Excite the activated ions in the slab-shaped gain medium 5 to the upper energy level to form population inversion. When the gain is greater than the loss, an oscillating laser is formed between the input mirror 7 and the output mirror 8 and output from the output mirror side .

Example 2

Referring to Fig. 2, the connection relationship of other structures is the same as that of Embodiment 1, the condenser cover 3 is covered outside the strip-shaped gain medium 5 and placed on the heat sink 6, and the strip-shaped gain medium 5 at the lower end of the condenser cover 3 is plated The position with anti-reflection coating is processed with a light outlet.

Example 3

As shown in reference 3, the connection relationship of other structures is the same as that of embodiment 1, and the focusing mirror 2 is a concave cylindrical reflector; 3. A light outlet is processed at the position where the anti-reflection film is coated on the slab-shaped gain medium 5 at the lower end.

Taking the connection relationship of Embodiment 2 as an example, different slab-shaped gain media 5, input mirror 7 and output mirror 8 are selected to form a laser oscillator or laser amplifier of a diode-pumped slab solid-state laser to verify its oscillation or amplification. Effect.

The slab-shaped gain medium 5 adopts a laser crystal with a size of 50mm×200mm×1.5mm; the input mirror 7 adopts a concave spherical mirror with a curvature radius of 600mm, and the structure is shown in Figure 6; the output mirror 8 adopts a convex cylindrical mirror with a curvature radius of -400mm; form a diode-pumped positive branch mixed cavity slab laser oscillator, the structure is shown in Figure 6; inject a pump power of 3500 watts, and obtain a laser output of 1100 watts; the beam quality ^M2 factor is better than 10.

The slab-shaped gain medium 5 adopts a laser crystal with a size of 100mm×100mm×3mm; the input mirror 7 adopts a concave spherical mirror with a radius of curvature of 1000mm; the output mirror 8 adopts a convex cylindrical mirror with a radius of curvature of -700mm; A mixed-cavity slab laser oscillator, the structure of which is shown in Figure 6; the injected pump power is 3000 watts, and the laser output of 1000 watts can be obtained; the beam quality ^M2 factor is better than 20.

The slab-shaped gain medium 5 adopts a laser crystal with a size of 10 mm × 40 mm × 0.6 mm; the input mirror 7 adopts a concave spherical mirror with a radius of curvature of 200 mm; the output mirror 8 adopts a concave spherical mirror with a radius of curvature of 150 mm; a diode-pumped negative-branch hybrid is formed The cavity slab laser oscillator has a structure as shown in Figure 7; the injected pump power is 850 watts, and a laser output of 300 watts can be obtained; the beam quality ^M2 factor is better than 2.

The slab-shaped gain medium 5 adopts a laser crystal with a size of 40mm×15mm×1mm; the input mirror 7 is a concave spherical mirror with a radius of curvature of 200mm; the output mirror 8 is a concave spherical mirror with a curvature radius of 150mm; a diode-pumped negative branch mixing cavity is formed The structure of the slab laser oscillator is shown in Figure 7; the injected pump power is 1000 watts, and a laser output of 350 watts can be obtained; the beam quality ^M2 factor is better than 5.

The slab-shaped gain medium 5 is made of laser ceramics with a size of 60mm×80mm×2mm; the input mirror 7 is a concave spherical mirror with a radius of curvature of 500mm; the output mirror 8 is a plane mirror, and the transmittance to the oscillating laser is T=25%; the diode is formed Pump a flat-concave stable cavity slab laser oscillator; the distance between the input mirror 7 and the output mirror 8 is 100 mm, and the structure is shown in Figure 8; injecting a pump power of 2000 watts can obtain a laser output of 800 watts.

The slab-shaped gain medium 5 uses a laser crystal with a size of 100mm×100mm×2mm; the input mirror 7 is a concave cylindrical mirror with a radius of curvature of 500mm; the output mirror 8 is a convex cylindrical mirror with a curvature radius of -350mm; the diode pump is formed Pu slab hybrid cavity laser amplifier, the structure is as shown in Figure 9; the seed light 9 is incident from one end of the slab-shaped gain medium 5, and propagates repeatedly in the resonant cavity formed between the input mirror 7 and the output mirror 8 to obtain power amplification, High power amplified light 10 is obtained.

The specific description above is a further detailed description of the purpose, technical solutions and beneficial effects of the present utility model. It should be understood that the above description is only a specific embodiment of the present utility model and is not intended to limit the present invention. Within the protection scope of the utility model, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the utility model shall be included in the protection scope of the utility model.

Claims (7)

1. diode pumping plate solid laser is characterized in that: comprise gain module, input mirror and outgoing mirror, wherein,

Described gain module comprises diode array, focus lamp, snoot, the slab gain media and heat sink that is made of a plurality of laser diodes, and wherein, the upper end of described snoot is provided with light inlet, and covers a big surface of described slab gain media; Big surface of another of described slab gain media and heat sink tight the connection, one group of opposite flank of described slab gain media is polished and be coated with anti-reflection film, as oscillation light or be exaggerated the logical light face of light; Described input mirror and described outgoing mirror lay respectively at the both sides of described lath gain module, and with described slab gain media on to be coated with two side surfaces of anti-reflection film relative, constitute resonant cavity, wherein,

After the pump light that diode array sends focuses on via focus lamp, enter the laser pump cavity of snoot and slab gain media composition by the light inlet of snoot upper end, go forward side by side into the slab gain media, active ions in the slab gain media are energized into energy level, form population inversion, when gain during, between input mirror and outgoing mirror, form oscillating laser and export from outgoing mirror one side greater than loss.

2. diode pumping plate solid laser according to claim 1 is characterized in that: described focus lamp is cylindrical lens, set of cylindrical lenses or recessed cylindrical mirror.

3. diode pumping plate solid laser according to claim 1 is characterized in that: the lower surface of described slab gain media and heat sink connected mode employing metal sealing or optical cement are bonding.

4. diode pumping plate solid laser according to claim 1 is characterized in that: described slab gain media is laser crystal or laser ceramics, and thickness is 0.5～3mm, and width is 10～100mm, and length is 10～100mm.

5. diode pumping plate solid laser according to claim 1 is characterized in that: described heat sinkly be connected with air cooling equipment, water-circulating cooling device or semiconductor cooler.

6. diode pumping plate solid laser according to claim 1, it is characterized in that: described input mirror is concave mirror or recessed cylindrical mirror, described outgoing mirror is protruding cylindrical mirror, and described input mirror and described outgoing mirror constitute positive-branch confocal unstable resonator on the plane at described slab gain media place.

7. diode pumping plate solid laser according to claim 1, it is characterized in that: described input mirror is a concave mirror, described outgoing mirror is a concave mirror, and described input mirror and described outgoing mirror constitute negative branch confocal unstable resonator on the plane at described slab gain media place.

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