Nd: Dual Wavelength Of Yag Medical Laser

Lots of new medical methods generated with the development of laser technology, foundation medicine study and their interfusion with other technology. These new technologies and research methods were continuously applied in various fields that in biomedical research, such as the physiological role of laser, coherent optical effects produced by photocoagulation, optical pulse caused by eye injuries, laser biological effects, laser beam on the skin effect and so on.Firstly, we introduced the present situation and treating principle of laser hair removal and laser treatment of vascular skin lesions. Then, we successfully developed a frequency doubling, E-O Q-switch and double pulse Nd:YAG laser by using electro-optical modulator, KDP crystal pulse amplifier and the method of Xenon lamp-pumped which based on the detailed theoretical analysis. The plan of obtain 1064nm laser and 532nm laser on the same laser was realized and 1064nm laser could be used to remove hair and 532nm laser could be used to treat vascular skin lesions. The following main aspects of work had been made in this paper:(1) Introduced the research background, significance and the characteristics of Nd:YAG laser. Discussed the Nd:YAG laser applications in medicine and its future development tendency.(2) Researched the xenon lamp-pumped Nd:YAG dual-wavelength lasers applied with Q switching theory and theory of nonlinear optical frequency-doubling. The factors that affect the efficiency of frequency doubling were discussed. By analyzing the characters of several kinds of nonlinear crystals, KDP crystal was selected as the nonlinear frequency-doubled crystal for 1064nm and 532nm laser was obtained by using outer cavity enlargement and outer frequency-doubled structural. In addition, the best length and the best azimuth angle of the nonlinear frequency-doubled crystal were discussed.(3) The overall structure of the laser system has been designed and the output energy of the laser was developed by amplifying used the Nd:YAG laser as pulse amplifier. The parameters of the cavities were given and a simple structure laser system was optimized. The laser system had high precision of adjusting and simple structure.(4) Realized normal operating of double-pulsing frequency Q-switch Nd:YAG laser. By experiment, we obtained 1.25J pulse energy of based single-frequency optical which pulse width is 15ns and the pulse energy of harmonic is 0.5J which pulse width is 7.72ns. Realized normal operating of E-O Q-switch Nd:YAG laser.