Abstract
The second harmonic generation(SHG) of continuous wave chemical oxygen iodine laser(COIL) has been studied. Second harmonic of COIL has characteristics of the short wavelength of 0.658μm and the visible laser. So our purpose is to apply this study to industrial process. The two types of LBO crystal were used as the nonlinear crystal. One was a cubic LBO crystal whose surface were AR coated and the other was Brewster cut LBO crystal which was not used AR coating and cut for Brewster angle. We used two types of concentric asymmetric resonator whose length were different each other. The second harmonic maximum output of 16.4W were obtained using the Brewster cut LBO crystal and the conversion efficiency was 0.51% just then. So we achieved higher power second harmonic by using Brewster cut LBO crystal.
