The Thermal Properties Of Composite Crystal And Experimental Research

Diode-pumped all-solid-state laser has lots of advantages, such as compact structure, high stability and optical-optical conversion efficiency. It is widely used in national defence, photoelectron industry, optical communications, medical treatment and sanitation. Laser crystal is the core of diode-pumped all-solid-state lasers, which decides the output characteristics of laser. In recent years, in an endeavor to obtain higher output powers from continuous-wave end-pumped solid-state lasers, one must consider thermal effects that will impact optical performance. With the development of high power diode lasers, high power DPSSL has become one of the main objectives of current research and development activities within the laser community. Research of DPSSL has mainly concentrated on scaling of output power, while remaining of a high spatial beam quality. The main problem hindering scaling of diode-pumped solid-state lasers is heat deposition within the laser medium. The main reasons that produces thermal effect is:1. As there is difference between the pump energy and laser photon energy, the pump is not completely converted to laser light, parts of the energy is released in the form of heat.2. Because the quantum efficiencies is less than 1 in the Laser transition fluorescence process, the heat is produced.3. The emission spectrum of the original pump is a certain width, and the laser gain medium can only absorb part of the spectrum of light or other light absorbing matrix may be generated heat.In this paper, the rectangular section of hot model of laser crystals is established,which starts from the actual application, and solves the Possion equation. On basis of a composite crystal YVO₄/Nd:YVO₄, a new module of all-solid-state green laser with YVO₄/Nd:YVO₄/ YVO₄/KTP composite crystal as laser material is devised, then by using matlab programming, 17pm of the max deformation distribution between YVO₄/Nd:YVO₄/YVO₄ and KTP is sovled. The composition of YVO₄/Nd:YVO₄/YVO₄ and KTP crystal can not produce interspace or fracture for the unevenness of thermal stress. So we have a conclusion that YVO₄/Nd:YVO₄/ YVO₄/KTP made as the working nedium of a green laser is feasible.High-power Nd:YAG solid laser has become competitive processing illuminant, because it has lots of advantages, such as shorter wavelengths (relative to the CO2 laser), high absorptivity, high absorptivity, optical fiber transmission and so on. In this paper, the main describes the galvanometer laser marking machine, through the recorded data, the experimental input power and output power relationship is simulated, and the thermal focal length of 25℃has been through several experiments the stability of the right cavity.This paper is divided into four parts. It is (1) summary; (2) the theoretical analysis of the composita crystal; (3) the introduction of the frequency-doubled and the feasibility of YVO₄/ Nd:YVO₄/YVO₄; (4) a brief introduction of the laser marking machine and Nd: YAG laser marking machine module as a source of performance test; (5) full-text summary.(1) LD-pumped solid state laser development process is briefly reviewed; introduction the solid-state lasers has two methods of work: continuous and pulse, and ways to achieve pulse: Active Q-switched and passive Q-switched; A brief introduction end-pumped, side-pumped and comer-pumped three pumping angle and several commonly used for end-pumped laser crystal and the nonlinear crystal KTP.(2) Under the basic of theory thermal effect of laser crystals, the rectangular section of hot model of laser crystals is established and study the thermal effect of laser media, and learn the source that aware of uneven distributionof the laser medium temperaturelead to thermal stress, birefringence effect and the thermal lens effect, and research the heat effect causes.(3) First, the frequency doubling technology is described. In continuous fundamental oscillator, the cavity power density is much larger than cavity, while the second harmonic power is proportional to the square with the fundamental power, so frequency doubling crystal should be placed in cavity waist position. We propose the solution that the big end deformation lead to rupture when the backside of composite crystal YVO₄/Nd:YVO₄ bonds KTP, that is, YVO₄/Nd:YVO₄ and KTP bonding between the YVO₄, and its feasibility is demonstrated.(4) The development of laser marking machine is described, and the galvanometer marking the structure and mode of operation is highlighted. The transfer matrix cavity is introduced and the performance of Nd:YAG modules is tested. (5) Research on the topic are summarized, and further made a number of interesting directions.