Experimental Study Of The Tunable Cw Quasi-phase-matched Optical Parametric Oscillator

Continuous-wave optical parametric oscillators (cw OPOs ) are an attractive source of coherent radiation in applications for which laser sources are unavailable or for which wide tunablity is needed, cw OPOs have remarkable features of operating with narrow linewidth and broad tunablity. So they can be used for spectroscopy, coherent communication and quantum optical studies. They also can produce various kinds of nonclassical states of light generation of squeezed vacuum below threshold, of strongly intensity-correlated twin beam above threshold and quadrature squeezing of the pump wave above threshold.Many OPO implementations are limited by problems with conventional birefiingent phase-matched techniques in available materials, such as Poynting-vector walk-off, low effective nonlinear coefficient, and inconvenient phase-matching temperature and angles. In recent years, interest in OPO's has been renewed by advances in stable pump lasers and improvements in nonlinear optical material.This thesis is devoted to various studies involving quasi-phase matched optical parametric oscillator. It is formed by four parts:1) In this part we briefly introduce the type of OPOs and the developments of OPOs.2) The classical characteristics of quasi-phase-matched triply resonant optical parametric oscillator (TROPO) are theoretically analyzed. We confirm its tuning characteristics by changing crystal's temperature in our experiment The wavelength of the OPO output can be tuned from 1988nm to 2293nm with the crystal's temperature range of 8 degree.3) The quantum noise characteristics of the output of TROPO are theoretically analyzed and the intensity-diflerence squeezing of two down-conversion beams was experimental obtained. The intensity-difference noise reduction was 0.4dB.4) The tuning characteristics of doubly-resonant optical parametric oscillator PROPO) output by changing crystal's temperature, OPO's cavity length and pump frequency respectively are theoretically analyzed and experimental obtained The wavelength of the OPO output can be tuned from 2038nm to 2227nm by the crystal's temperaturechanged of 5.3 , from 2044nm to 2219nm by the cavity length changed of 514nm, and 375MHz by the pump frequency continuously tuned 750MHz. 5) Conclusion and prospect...