Beam near-field intensity distribution self-homogenizing high-energy laser device

Abstract

The invention discloses a beam near-field intensity distribution self-homogenizing high-energy laser device. The device includes a beam rotation system, wherein the beam rotation system includes at least five reflectors of an odd number, the five reflectors are set as a first reflector, a second reflector, a third reflector, a fourth reflector and a fifth reflector, all the reflectors are in the same optical principal plane, and a center connection line of the first reflector and the fifth reflector constitutes a rotation axis of the beam rotation system. The device is advantaged in that the beam rotation system enables same-optical axis transmission of an incident beam and an outgoing beam, uniform distribution of the light field in a cavity is achieved through utilizing the gain self-compensation effect during beam rotation, the beam quality of the laser device is effectively improved, moreover, combined with a shaping beam expanding system and the beam rotation system, the laser mode volume is fully expanded, and the utilization rate of gain zone activated particles is improved.

Description

technical field [0001] The invention belongs to the technical field of lasers, and in particular relates to a self-homogenizing high-energy laser with near-field intensity distribution of light beams. Background technique [0002] During the operation of high-power lasers, due to the influence of factors such as pumping inhomogeneity, thermal effects, and gain medium defects, the spatial inhomogeneous distribution of laser gain occurs. On the other hand, high power lasers typically have gain factors up to 10m -1 , the uneven gain will lead to serious distortion of the laser light intensity distribution and the degradation of the beam quality, which is not conducive to the high efficiency and high power output of the laser, and also limits the application effect of the laser. [0003] At present, there are many technical means to improve the gain inhomogeneity of laser beam: [0004] 1. Improve the quality of the gain medium so that the activated particles are evenly distri...

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Problems solved by technology

[0004] 1. Improve the quality of the gain medium so that the activated particles are evenly distributed in space. The disadvantage of this method is that the cost is high, especially for the large-size gain medium, it is very difficult to achieve a uniform distribution of various physical properties;

[0005] 2. By rationally designing the pump light path design, the pump light is evenly distributed in the gain medium. This method is often affected by the quality of the pump source beam, and it is difficult to achieve high uniformity of gain;

[0006] 3. After the laser emits light, load the beam with a random phase or rotate the beam to homogenize the processed laser. This method does not affect the operation of the laser itself, so it cannot improve the efficiency and beam quality of the laser itself

The typical representative of this kind of method is the 90° rotating resonator (UR90) laser, which can realize the homogenization of the output light field. However, this kind of laser generally rotates the light field by 90° in the cavity. For some special gain distribution (90°rotational symmetry), the homogenization effect of the beam is limited. If the rotation angle is changed, the installation angle of the entire resonator needs to be changed, and the adjustment process is more complicated; at the same time, because the beam rotation transmission process is not in the same plane, an additional beam needs to be set in the cavity Translational system, increasing system complexity

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