| 摘要 |
PURPOSE:To improve the efficiency of SHG (2nd higher harmonic generation) conversion by forming a light guide which is longer than a substrate in an X and an Y axial direction on the Z surface of nonlinear optical crystal having an X, an Y, and a Z axis. CONSTITUTION:The light guide which is 6mum wide and 4mum deep is formed by diffusing thermally Ti in the Z surface of the LiNbO3Z plate 3' which is, for example, 2cm in the X axial direction and 1cm long in the Y axial direction. Light with wavelength lambda is made incident on this light guide 4a from its incidence end part 5 and reflected by a reflecting end part 6 where a metallic film is vapor-deposited to propagate to the next light guide 4b. The light guides (a) and (b) are at a 3 deg. angle to each other. Light entering the light guide 4c similarly is projected from a projection end part 7. The overall length of the light guides is about 6cm. Then, the incident light with the wavelength lambda and light of a converted wave with wavelength lambda/2 are put in phase with each other to maximize the output power of the converted wave. In practice, semiconductor laser light which has 1.3mum wavelength and 40mW output power is converged by a lens, made incident on the incidence end part 5, and put in phase by temperature to obtain a bit over 20% conversion efficiency. |
