Ar~+ Laser - Pumped Research On Continuous Ktp Optical Parametric Oscillator

Optical parametric oscillator (OPO) is an attractive source of coherent radiation in applications for which laser sources are unavailable or for which wide tunablity is needed. Continuous wave optical parametric oscillator (CW-OPO) has remarkable features of operating with narrow linewidth and broad tunablity. So it can be used for spectroscopy, coherent communication and quantum optical studies. At present, studies on CW-OPO are mostly based on the periodically poled crystal and quasi-phase matching(QPM) technique. But suffer by the limit of the thickness, length, quality and cost of periodically poled crystal , QMP technique is hardly applied to low-power and low-energy OPO. KTP crystal has superior overll properties, and its growth technology is very mature, large-size crystal can be grew at low cost. Ar~+ laser has superior directionality and monochromaticity, in addition,it is also the laser that can output the highest continuous-wave(CW) power at visible light region. So studies on the CW-KTP-OPO pumped by Ar~+ laser have superior scientific research and commercial value.Firstly, the development history and research actuality of OPO in-country and overseas is summarized. Also, the application of OPO is introduced. And then, the significance of this thesis is presented compared to the OPO based on the periodically poled crystal and quasi-phase matching technique.Secondly, the principium of the OPO is explained.Then, on the basis of coupled wave equations, theoretically studies of CW-OPO's threshold parameters, conversion efficiency and phase matching are presented.Thirdly, on 1he basis of the physical and chemical characters, optical characters and nonlinear characters of KTP crystal, the parameters such as effective nonlinear coefficients, walk-off angle and acceptance angle are calculated and discussed, togther with elaborate analysis to phase-matching process and operation characters of CW-KTP-OPO pumped by Ar~+ laser.Finally, the experiment is designed and the scheme is presented.