MOPA pulse solid laser combining LD end pump and side pump

Abstract

The invention relates to the technical field of laser measuring and illuminating devices, and discloses an MOPA pulse solid-state laser combining an LD end pump and a side pump, which comprises an oscillation stage and an amplification stage, the oscillation stage comprises an LD bar array I, the LD bar array I is provided with an Nd: YAG crystal rod in a coupling mode in the light path direction, the Nd: YAG crystal rod is provided with a polaroid in the light path direction, and the polaroid is sequentially provided with a lambda / 4 wave plate and an RTP electro-optic Q-switch in the light path direction; the lambda / 4 wave plate and the RTP electro-optic Q-switch which are sequentially arranged are used for converting the p-direction polarized light into s-direction polarized light and outputting the s-direction polarized light to the amplifier stage; the amplification stage comprises a lambda / 2 wave plate for receiving polarized light in the s direction output by the oscillation stage, the lambda / 2 wave plate is provided with an Nd: YAG lath crystal in the light path direction, and a second LD bar array serving as a laser pumping source is arranged above the Nd: YAG lath crystal in parallel; the laser pulse width meeting the guidance requirement is met, meanwhile, the light-to-light conversion efficiency is improved, the laser energy is increased, the beam divergence angle is small, the laser optical axis stability is effectively improved, and then the laser guidance precision is improved.

Description

Technical Field

[0001] The present application relates to the technical field of laser photometers, and in particular to a MOPA pulse solid-state laser combining an LD end pump with a side pump. Background Art

[0002] The laser light finder is one of the important optoelectronic loads of the laser semi-active homing guidance system. In the past 20 years, relevant units in China have made great progress in the development of this laser equipment in terms of laser design, optical system design, optoelectronic signal detection and LD drive circuit design, which is manifested in the pursuit of miniaturization and lightweight design, and the requirements for laser, optical and electronic control technical indicators are becoming more and more stringent. From the perspective of laser technology, from the initial lamp pump + water cooling method 20 years ago to the current LD pump + air cooling or even temperature-free design scheme, the size and weight of the laser are getting smaller and smaller, and the requirements for core indicators such as laser energy, beam divergence angle and optical axis stability are gradually increasing. Its application range involves different combat platforms such as single-soldier handheld equipment, ship-borne, vehicle-borne, airborne and missile-borne optoelectronic pods of all arms. Its typical laser energy is 20mJ~120mJ, corresponding to a ranging distance of 3km~20km and an irradiation distance of 3km~10km.

[0003] With the demand for long-range combat, some domestic helicopters and fighter jets have been upgraded and iterated, requiring longer ranging and illumination capabilities. Therefore, the technical indicators of the laser light finder used in airborne optoelectronic pods have also been improved accordingly. For example, when the weight of the whole machine does not exceed 2.6kg, the laser energy is required to be 130mJ, the beam divergence angle is 0.015mrad, and it can achieve continuous multiple cycles of illumination (60s of illumination, 30s interval, and 4 consecutive cycles) at an ambient temperature of -45℃ to 70℃, especially continuous operation at a high temperature of 70℃, which greatly increases the difficulty of laser design.

[0004] As for pulsed solid lasers above 130mJ used for laser guidance, the existing technology is that a single oscillation stage directly outputs 130mJ (taking into account the light blocking by the emitting lens or the inherent transmittance loss of 5% to -10%, the actual laser energy should be around 150mJ). The advantages of the existing technology are that there are few laser devices, low cost, and relatively easy installation and adjustment, but there are strict restrictions on size and weight. For example, the current domestic proposed machine length does not exceed 280mm and the weight does not exceed 2.6kg. From the theoretical and practical engineering experience design, a single oscillation level output of 150mJ is achievable, but on the one hand, due to the serious limitation of the laser resonant cavity length of the existing technology, the laser pulse width is usually only 5ns~7ns, and the detection response rising edge of the four-quadrant detector of the laser spot tracker of the seeker in the laser guidance requires that the laser pulse width needs to be designed within the range of 10ns~20ns to ensure that each pulse laser can be detected. If the pulse width is too small, there will be a certain probability that the seeker will lose the code, and the laser cannot be detected by the seeker under certain codes, which not only affects the accuracy of laser guidance, but also may cause off-target phenomenon and fail to accurately hit the target. On the other hand, when the existing technology outputs 150mJ of laser energy, the stability of the laser optical axis usually cannot meet the requirement of being able to maintain within 0.05mrad or 0.03mrad under each irradiation cycle.

[0005] Application Contents

[0006] The purpose of this application is to provide a MOPA pulse solid laser that combines an LD end pump and a side pump to meet the guidance requirements, while improving the light-to-light conversion efficiency, increasing the laser energy, and a smaller beam divergence angle, effectively improving the laser optical axis stability, thereby improving the laser guidance accuracy.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] The MOPA pulse solid laser of the present invention, which combines an LD end pump with a side pump, comprises an oscillation stage and an amplification stage;

[0009] The oscillation stage comprises an LD bar array 1 as a laser pump source, the LD bar array 1 is coupled with an Nd:YAG crystal rod along the optical path, the Nd:YAG crystal rod is provided with a polarizer for converting laser light into p-direction polarized light along the optical path, the polarizer is provided with a λ / 4 wave plate and an RTP electro-optical Q-switching switch in sequence along the optical path, the λ / 4 wave plate and the RTP electro-optical Q-switching switch arranged in sequence are used to convert p-direction polarized light into s-direction polarized light and output it to the amplifier stage;

[0010] The amplifier stage includes a λ / 2 wave plate for receiving s-direction polarized light output by the oscillation stage. The λ / 2 wave plate is provided with a Nd:YAG slab crystal along the optical path. An LD bar array 2 as a laser pump source is arranged in parallel above the Nd:YAG slab crystal.

[0011] Furthermore, the Nd:YAG slab crystal is in the form of a trapezoidal table, the light-facing surface of the Nd:YAG slab crystal is an inclined surface, and the longer surface of the Nd:YAG slab crystal is disposed close to the second LD bar array.

[0012] Furthermore, the bars of the LD bar array 2 are arranged at equal intervals according to the upper surface size of the trapezoidal long side of the Nd:YAG slab crystal, the fast axis of a single bar is parallel to the length direction of the Nd:YAG slab crystal, and the slow axis of a single bar is parallel to the width direction of the Nd:YAG slab crystal.

[0013] Furthermore, a total reflection mirror is arranged in the direction of the optical path between the Nd:YAG crystal rod and the LD bar array 1, the total reflection mirror is a plano-concave mirror, and the concave surface of the total reflection mirror is arranged close to the Nd:YAG crystal rod, and an output mirror is arranged at the optical path output end of the RTP electro-optical Q-switched switch, the output mirror is a concave-convex mirror, and the convex surface of the output mirror is the light-facing surface.

[0014] Furthermore, a coupling mirror group is provided in the optical path direction between the total reflection mirror and the LD bar array 1 for shaping and focusing the fast axis and slow axis directions of the LD bar array 1 respectively.

[0015] Furthermore, a wedge mirror pair for fine-tuning the intra-cavity optical path is provided in the optical path direction between the output mirror and the RTP electro-optical Q-switch.

[0016] Furthermore, a corner cube prism for folding the light path is arranged in the light path direction between the Nd:YAG crystal rod and the polarizer.

[0017] Furthermore, the LD bar array 1 is horizontally arranged in parallel with the Nd:YAG slab crystal and the LD bar array 2.

[0018] Compared with the prior art, the beneficial effects of this application are:

[0019] 1. Technical indicators that can meet the requirements of precision guidance, including high energy (greater than 150mJ), pulse width (greater than 10ns) and small beam divergence (less than 1.3mrad@20Hz);

[0020] The laser pulse width of the present application depends on the oscillation stage. The amplification stage amplifies the energy without compressing the pulse width. As long as the oscillation stage controls the pump power so that the pulse width is greater than 10ns, the pulse width can still be greater than 10ns after passing through the amplification stage. At the same time, the amplification stage adopts Nd:YAG slab crystal with good heat dissipation performance, and utilizes its polarized light incident characteristics, so that the beam quality of the seed light after total reflection inside the Nd:YAG slab crystal does not deteriorate due to depolarization caused by thermal lens or welding stress, which can ensure that the divergence angle of the laser beam after amplification can still be controlled within 1.3mrad at 20Hz light output.

[0021] 2. The light-to-light conversion efficiency is high by utilizing polarization characteristics, and the quality of the laser beam remains basically unchanged after amplification;

[0022] The s-direction polarized light output by the oscillator stage of the present application is changed in polarization direction to p-direction polarized light through a λ / 2 wave plate, and the incident inclined plane of the trapezoidal Nd:YAG slab crystal is cut according to the Brewster angle, so that all p-light can be transmitted, thereby increasing the transmittance of the seed light entering the slab crystal, ensuring that the laser light totally reflected inside the slab crystal has only p-component polarized light, slowing down the deterioration of the beam quality of the seed source laser during the amplification process, and effectively improving the stability of the laser optical axis;

[0023] 3. The LD bar array 2 of the amplification stage is small in size and is arranged in parallel with the LD bar array 1 of the oscillation stage, which is convenient for temperature control;

[0024] The invention comprises an amplification stage of an LD bar array 2 and an Nd:YAG slab crystal. The bars of the LD bar array 2 are arranged at equal intervals according to the upper surface size of the long side of the trapezoid of the Nd:YAG slab crystal. The fast axis of a single bar of the LD bar array 2 is parallel to the length direction of the crystal, and the slow axis is parallel to the width direction of the crystal. The structure of the entire LD bar array 2 is compactly arranged and is arranged in parallel with the LD bar array 1 of the oscillation stage, so as to facilitate heat dissipation and temperature control through the same radiator. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the implementation methods of the present application, the drawings required for use in the implementation methods will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is the structural principle diagram of this application;

[0027] Figure 2 It is a schematic diagram of the overall structure of this application from one angle;

[0028] Figure 3It is a schematic diagram of the overall structure of the present application from another angle;

[0029] Figure 4 It is a top view of the overall structural schematic diagram of the present application.

[0030] Reference numerals: LD bar array 1; coupling mirror group 2; total reflection mirror 3; Nd:YAG crystal rod 4; corner cube prism 5; polarizer 6; λ / 4 wave plate 7; RTP electro-optical Q-switching switch 8; wedge mirror pair 9; output mirror 10;

[0031] λ / 2 wave plate 11; LD bar array 12; Nd:YAG slab crystal 13. DETAILED DESCRIPTION

[0032] 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 following embodiments and features in the embodiments can be combined with each other without conflict.

[0033] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show the layers related to the present invention rather than being drawn according to the number, shape and size of the layers in actual implementation. In actual implementation, the type, quantity and proportion of each layer may be changed arbitrarily, and the layer layout may also be more complicated.

[0034] In the following description, numerous details are discussed to provide a more thorough explanation of embodiments of the present invention; however, it is apparent to one skilled in the art that embodiments of the present invention may be practiced without these specific details.

[0035] See also Figures 1 to 4 , a MOPA pulse solid-state laser combining LD end pump and side pump, including an oscillation stage and an amplification stage;

[0036] The oscillation stage includes an LD bar array 1 as a laser pump source, the LD bar array 1 is coupled with an Nd:YAG crystal rod 4 along the optical path, the Nd:YAG crystal rod 4 is provided with a polarizer 6 for converting laser light into p-direction polarized light along the optical path, the polarizer 6 is sequentially provided with a λ / 4 wave plate 7 and an RTP electro-optical Q-switching switch 8 along the optical path, the λ / 4 wave plate 7 and the RTP electro-optical Q-switching switch 8 sequentially provided are used to convert p-direction polarized light into s-direction polarized light and output it to the amplifier stage;

[0037] The amplifier stage includes a λ / 2 wave plate 11 for receiving s-direction polarized light output by the oscillation stage. The λ / 2 wave plate 11 is provided with a Nd:YAG slab crystal 13 along the optical path. An LD bar array 12 as a laser pump source is arranged in parallel above the Nd:YAG slab crystal 13.

[0038] See also Figures 1 to 3 The Nd:YAG slab crystal 13 is in the form of a trapezoidal platform, the light-facing surface of the Nd:YAG slab crystal 13 is an inclined surface, and the longer side of the Nd:YAG slab crystal 13 is disposed close to the LD bar array 2 12 .

[0039] See also Figures 1 to 3 The bars of the LD bar array 12 are arranged at equal intervals according to the upper surface size of the trapezoidal long side of the Nd:YAG slab crystal 13, the fast axis of a single bar is parallel to the length direction of the Nd:YAG slab crystal 13, and the slow axis of a single bar is parallel to the width direction of the Nd:YAG slab crystal 13.

[0040] See also Figure 1 A total reflection mirror 3 is arranged in the optical path direction between the Nd:YAG crystal rod 4 and the LD bar array 1, the total reflection mirror 3 is a plano-concave mirror, and the concave surface of the total reflection mirror 3 is arranged close to the Nd:YAG crystal rod 4, and an output mirror 10 is arranged at the optical path output end of the RTP electro-optical Q-switching switch 8, the output mirror 10 is a concave-convex mirror, and the convex surface of the output mirror 10 is the light-facing surface.

[0041] See also Figure 1 A coupling mirror group 2 is provided in the optical path direction between the total reflection mirror 3 and the LD bar array 1 for shaping and focusing the fast axis and slow axis directions of the LD bar array 1 respectively.

[0042] See also Figures 1 to 4 A wedge mirror pair 9 for fine-tuning the intra-cavity optical path is provided in the optical path direction between the output mirror 10 and the RTP electro-optical Q-switch 8 .

[0043] See also Figures 1 to 4 A corner cube prism 5 for folding the light path is arranged in the light path direction between the Nd:YAG crystal rod 4 and the polarizer 6 .

[0044] See also Figure 4 The LD bar array 1, the Nd:YAG slab crystal 13 and the LD bar array 2 12 are arranged horizontally in parallel.

[0045] See also Figures 1 to 4The oscillator stage of the present application outputs 1064nm pulsed laser through Nd:YAG crystal rod 4, adopts unstable cavity technology, selects crystals with suitable parameters, avoids ASE parasitic oscillation and other problems, obtains pulsed laser with high beam quality, and controls the energy at about 80mJ, and the pulse width can be greater than 10ns. The laser is output as a seed source and enters the amplifier stage including Nd:YAG slab crystal 13 and LD bar array 12 for amplification (only the first-stage amplification is described here. In theory, if the spot mode and pump uniformity are well matched, the second-stage or multi-stage amplification can also be performed to achieve higher laser energy output). After the oscillator stage laser enters the trapezoidal Nd:YAG slab crystal 13, it is amplified in the crystal according to the Zigzag total reflection path. The seed light energy and the pump light are fully overlapped and amplified, which not only improves the light-to-light conversion efficiency and increases the laser energy, but also benefits from the good heat dissipation performance of the slab crystal, greatly slowing down or avoiding the serious thermal lens effect on the laser light. The deterioration of beam quality makes the high beam quality laser output by the oscillation stage maintain the original high beam quality during the process of energy amplification, so that the amplified laser still has a small beam divergence angle, effectively improving the stability of the laser optical axis. The output can still be controlled within 1.3mrad at an energy of 150mJ, and the pulse width still depends only on the oscillation stage. As long as the oscillation stage pump power and gain remain unchanged, the pulse width of the oscillation stage will remain constant. The energy increases during the amplification process, but the pulse width will not narrow, but will be slightly widened by about 1ns. As long as the oscillation stage pulse width is controlled above 10ns, the amplified laser pulse width can meet the requirements of laser guidance of 10ns to 20ns.

[0046] The resonant cavity of the present application adopts a typical and mature U-shaped folded cavity structure unstable cavity design scheme, which can achieve 80mJ level 1064nm pulse laser output. The cavity length is designed to achieve a pulse width of more than 10ns at 80mJ. Depending on the spot mode and gain in the cavity, the cavity length usually needs to be guaranteed to be more than 260mm;

[0047] The present application includes an oscillator stage and an amplifier stage. The pump source of the oscillator stage adopts a high-temperature 808nm LD bar array-1. The pump peak power of the LD bar array-1 is 4kW. 20 bars are used to form an array. Each bar is arranged along the fast axis direction, and the fast axis collimation range is 3°-5°.

[0048] See also Figures 1 to 4 The light outputted by the LD bar array 1 is shaped and focused to the light-facing surface of the Nd:YAG crystal rod 4 in the fast axis and slow axis directions respectively by the coupling mirror group 2. The coupling mirror group 2 adopts a three-piece cylindrical lens combination to focus the pump spot to an approximately circular spot with a diameter range of 3 to 4 mm, so as to match the laser spot mode in the cavity;

[0049] The total reflection mirror 3 is designed between the coupling mirror group 2 and the Nd:YAG crystal rod 4, and adopts a plano-concave mirror. The side (flat surface) close to the LD bar array 1 is coated with a 1064nm anti-reflection film in the range of 780nm to 810nm, and the side (concave surface) close to the Nd:YAG crystal rod 4 is coated with a 1064nm high-reflection film;

[0050] The Nd:YAG crystal rod 4 uses a bonded crystal with a gradient doping concentration from 0.3% to 0.8%, which reduces the influence of thermal lens on beam quality and suppresses ASE spontaneous radiation amplification to increase laser output energy;

[0051] Corner cube prism 5 is used to fold the optical path, so that the optical path in the cavity is reversed 180 degrees from the first arm to the second arm after three total reflections. Due to its own optical characteristics, corner cube prism 5 has the advantage of anti-detuning and is a commonly used optical element for military lasers, so that the laser can still maintain stable laser energy output in the cavity optical path under high and low temperature or vibration environment;

[0052] After the optical path enters the second arm, the laser passes through the polarizer 6 to become p-polarized light, and then passes through the λ / 4 wave plate 7 and the RTP electro-optical Q-switching switch 8 to become s-polarized light output;

[0053] The wedge mirror pair 9 is used to fine-tune the optical path in the cavity. The output mirror 10 is a concave-convex mirror, which together with the total reflection mirror 3 forms an unstable cavity. The design of cavity mirror parameters and LD pump light size meet the mode matching.

[0054] See also Figures 1 to 4 The amplifier stage of the present invention takes into account the polarization characteristics of the output light of the oscillation stage. The λ / 2 wave plate 11 of the amplifier stage rotates the polarization direction of the s-polarized light output by the oscillation stage by 90° to become p-polarized light, which all enters the trapezoidal Nd:YAG slab crystal 13 and is amplified by total reflection through the Nd:YAG slab crystal 13. The p-polarized light that may exist in the oscillation stage becomes s-polarized light after passing through the λ / 2 wave plate 11, and is totally reflected by the inclined surface of the trapezoidal Nd:YAG slab crystal 13 and cannot enter the Nd:YAG slab crystal 13, so that the laser light entering the Nd:YAG slab crystal 13 for amplification has only one polarization state. Compared with the prior art that does not consider the polarization characteristics, the laser light output by the oscillation stage has both p-polarized light and s-polarized light, and is directly amplified. Due to the birefringence effect, the phase difference of different polarized lights is different, which will aggravate the depolarization problem and make the laser beam quality deteriorate more seriously. While the present application effectively improves the light-to-light conversion efficiency, the laser beam quality after amplification is equivalent to that of the oscillation stage;

[0055] The Nd:YAG slab crystal 13 of the amplifier stage adopts a trapezoidal slab crystal, and the incident end face (i.e., the light-facing face) is cut according to the Brewster angle. The advantage is that the end face can fully transmit p-polarized light and reflect s-polarized light without the need for anti-reflection film coating. The cross-sectional area of ​​the end face adopts a typical 5mm×5mm size design, and the length matches the LD bar array 2 12 (i.e., the pump source) above.

[0056] The pump source adopts a high-temperature 808nm LD bar array 12. The fast axis of the bar chip is arranged along the length of the crystal rod. The entire LD bar array 12 is compactly distributed 1 to 2 mm above the Nd:YAG slab crystal 13. The upper surface is coated with an 808nm anti-reflection film to improve the crystal's absorption coefficient of the pump light.

[0057] The amplifier stage has a compact structure. The LD bar array 1 of the oscillation stage and the LD bar array 2 12 of the amplifier stage are arranged horizontally in parallel, which is convenient for heat dissipation through the same radiator to achieve temperature control, ensuring that the temperature control can meet the long-term irradiation of the whole machine at a high temperature of 70°C.

[0058] In the above-mentioned embodiments, although the present invention has been described in conjunction with the specific embodiments of the present invention, many replacements, modifications and variations of these embodiments will be apparent to those of ordinary skill in the art based on the foregoing description. The embodiments of the present invention are intended to cover all such replacements, modifications and variations falling within the broad scope of the appended claims.

[0059] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A MOPA pulse solid-state laser combining LD end pump and side pump, characterized in that: It includes an oscillating stage and an amplifying stage; The oscillation stage comprises an LD bar array (1) as a laser pump source, the LD bar array (1) is coupled with an Nd:YAG crystal rod (4) along the optical path, the Nd:YAG crystal rod (4) is provided with a polarizer (6) for converting laser light into p-direction polarized light along the optical path, the polarizer (6) is provided with a λ / 4 wave plate (7) and an RTP electro-optical Q-switching switch (8) in sequence along the optical path, the λ / 4 wave plate (7) and the RTP electro-optical Q-switching switch (8) being arranged in sequence for converting p-direction polarized light into s-direction polarized light and outputting it to the amplifier stage; The amplifier stage comprises a λ / 2 wave plate (11) for receiving s-direction polarized light output by the oscillation stage, the λ / 2 wave plate (11) is provided with a Nd:YAG slab crystal (13) along the optical path direction, and an LD bar array 2 (12) serving as a laser pump source is arranged in parallel above the Nd:YAG slab crystal (13).

2. A MOPA pulse solid-state laser combining LD end pump and side pump according to claim 1, characterized in that: The Nd:YAG slab crystal (13) is in the shape of a trapezoidal platform, the light-facing surface of the Nd:YAG slab crystal (13) is an inclined surface, and the longer side of the Nd:YAG slab crystal (13) is arranged close to the second LD bar array (12).

3. A MOPA pulse solid-state laser combining LD end pump and side pump according to claim 2, characterized in that: The bars of the LD bar array 2 (12) are arranged at equal intervals according to the upper surface size of the trapezoidal long side of the Nd:YAG slab crystal (13), the fast axis of a single bar is parallel to the length direction of the Nd:YAG slab crystal (13), and the slow axis of a single bar is parallel to the width direction of the Nd:YAG slab crystal (13).

4. The MOPA pulse solid-state laser combining LD end pump and side pump according to claim 1, characterized in that: A total reflection mirror (3) is arranged in the direction of the optical path between the Nd:YAG crystal rod (4) and the LD bar array (1); the total reflection mirror (3) is a plano-concave mirror, and the concave surface of the total reflection mirror (3) is arranged close to the Nd:YAG crystal rod (4); an output mirror (10) is arranged at the optical path output end of the RTP electro-optical Q-switching switch (8); the output mirror (10) is a concave-convex mirror, and the convex surface of the output mirror (10) is a light-facing surface.

5. The MOPA pulse solid-state laser combining LD end pump and side pump according to claim 4, characterized in that: A coupling mirror group (2) is provided in the optical path direction between the total reflection mirror (3) and the LD bar array one (1) for shaping and focusing the output in the fast axis and slow axis directions of the LD bar array one (1) respectively.

6. The MOPA pulse solid-state laser combining LD end pump and side pump according to claim 4, characterized in that: A wedge mirror pair (9) for fine-tuning the intracavity optical path is arranged in the optical path direction between the output mirror (10) and the RTP electro-optical Q-switching switch (8).

7. The MOPA pulse solid-state laser combining LD end pump and side pump according to claim 1, characterized in that: A corner cube prism (5) for folding the light path is arranged in the light path direction between the Nd:YAG crystal rod (4) and the polarizing plate (6).

8. The MOPA pulse solid-state laser combining LD end pump and side pump according to claim 7, characterized in that: The LD bar array one (1) is arranged horizontally in parallel with the Nd:YAG slab crystal (13) and the LD bar array two (12).

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