Study Of Infrared Optical Parametric Oscillator With Broad Band And Its Application

The Optical Parametric Oscillator(OPO) has been widely used as a wavelength tunable coherent radiation source, since it offers a broad tuning range from ultraviolet to far infrared, and some of its wavelengths are unaccessible to common laser systems, so OPO has great value of application. In this paper, some crucial aspects on the design of OPO are investigated in detail, and the output characteristics of surelite OPO and mirage3000B are tested and analyzed. Further -more,cavity-ring-down is researched as one of the application of OPO. OPO and its application are studied in detail as follows:1. The development of OPO and its resonant theory are introduced. We discuss how to select crystal ,the type of phase matching and tuning precision, which offers some theoretical references to the design for tunable OPO.2. The device of surelite OPO and mirage3000B are analyzed, and some experimental results of the output wave and energy are obtained and discussed .3. As for the application of OPO, we describe the theory of measuring mirror reflectivity by cavity-ring-down, which use the output of OPO as a source, and demonstrate that cavity-ring-down is a more precise method by contrast to conventional measurements. In order to perform our experiment, we make a theroretical analyse of the experimental device, such as the laser source, resonantcavity, detector and oscillograph, and also discuss the influence of the measurement of ring-down time and the length of cavity on the experimental precision.4. We design the experiment of acvity-ring-down to measure reflectivity of the mirrors of COIL and DF laser with high reflectivity respectively at wavelength 1.315 m and 3.8 m, and perform the experiment of measuring reflectivity of COIL laser resonant mirrors. The experimental result is discussed in detail.With the development of infrared tunable OPO,its application is more and more wide.lt is possible for us to estimate the quality of resonant mirrors in laser with high energy and to improve the output energy of laser,by measuring the reflectivity of resonant mirrors of COIL and DF laser by cavity-ring-down which use output wave of OPO as the laser source, instead of COIL and DF laser with high price and huge space.