Research Of Double End-pumped Intracavity Frequency Doubling, Third Harmonic Of Ultraviolet Laser 355nm

UV laser micro-processing field in a wide range of industrial applications such as industrial parts marking, drilling, scribing, welding, cutting and micro-machining medical devices, electronic components, packaging, three-dimensional micro parts molding. In addition, in microelectronics, spectroscopy, optical data storage, atmospheric sounding, photobiology, optical communication, laser-induced fluorescence and UV absorption of atomic material and medical and other fields also have broad application prospects [1-3]. Because of the short wavelength UV laser and high-photon energy characteristics of the focusing spot can be smaller, while high-energy ultraviolet photons molecular bonds directly damage the material, relative to the infrared laser of the "hot melt" process, UV laser processing is the "cold eclipse "effect, which makes the processing of size can be smaller and processing accuracy is improved [4]. This paper focuses on the theoretical analysis of UV laser and experimental study.Describes the advantages of solid-state lasers and ultraviolet laser research background and research status at home and abroad. From the laser rate equation, introduced Q-laser peak power, pulse energy and pulse of the time parameters, the physical substance of swap Q analysis. From the three-wave coupled wave equation, the analysis of the phase matching conditions are given and the frequency multiplier with the theory and the second harmonic and third harmonic conversion efficiency of the implementation of high conditions. Introduced the Nd: YVO4, LBO crystal optical properties. Consider the thermal effect of the laser gain crystal resonator analysis and design.Contents of this research project: to design a cavity frequency, and frequency of the output wavelength of 355nm ultraviolet laser, technical specifications for the weight-frequency 10-40Hz, M2≤1.5, stability power 3-5W, power stability <5%, the laser 30W dual-side of the proposed LD-pumped semiconductor gain crystal Nd: YVO4, acousto-optic Q-1064nm fundamental frequency generated by the first piece of nonlinear crystal LBO, with Class I 532nm temperature phase matching second harmonic generation, and through the first two nonlinear crystal LBO, angle class II phase matching with UV 355nm laser generated.The project has three main aspects:I: Analysis of the gain crystal Nd: YVO4 thermal lens effect, design a beam quality close to the base model, the fundamental frequency of about 22W output power stability of the laser cavity.II: LBO crystal dispersion equation by the selected type doubling crystal LBO I phase matching temperature of temperature, with semi-analytical thermal analysis method for solving nonlinear LBO crystal temperature gradient, temperature control to adjust the output power of second harmonic 532nm The purpose of the 10W or so. III: LBO crystal dispersion equation by solving the selected type and frequency of the crystal LBO II phase matching angle of the temperature, the temperature and crystal angle adjustment. Finally, to stabilize the output power to a 3-5W UV 355nm laser purposes.