| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the conversion efficiency in a nonlinear optical crystal. SOLUTION: The temperature of a holder 112 is adjusted by a Peltier element 115a so that the temperature of a PPLN crystal 111 is so kept in a temperature range that the conversion efficiency of the crystal becomes the maximum, and the PPLN crystal 111 is arranged with respect to the holder 112 so that the difference between the upper limit temperature and the lower limit temperature of the PPLN crystal 111 stays within 0.1 deg.C on the basis of the temperature distribution along the optical axis of the holder 112 detected by a thermistor.</p> |
