| 摘要 |
PURPOSE:To enable a laser tube to oscillate laser rays in two or more wavelengths which have a comparatively large difference between them by a method wherein a film structure of a highly reflective mirror and an output mirror which constitute an optical resonator is specified. CONSTITUTION:Laminated sections A and B are deposited on an output mirror, where the laminated section A is structured in such a manner that a low refractive dielectric layer L and a highly refractive dielectric layer H, whose optical thicknesses are one fourth of lambda0 (lambda0 denotes a nearly average wavelength of two or more laser output wavelengths) respectively, are alternately laminated symmetrically on the front and the rear of a highly refractive dielectric layer 2H or a low refractive dielectric layer 2L, whose optical thickness is one half of lambda0 respectively, in a specified number of layers. The laminated section B is structured in such a manner that a highly refractive dielectric layer H and a low refractive layer 1 whose optical thicknesses are one fourth of lambda0 are alternately laminated in a specified number of layers. By these processes, a reflective band containing a wavelength which needs to oscillate and a transmissive band containing a wavelength which needs to be restrained from oscillation can be sharply divided, and a Q value of a resonator with regard to a wavelength which needs to oscillate can be easily set within the range of a specified value, so that laser rays with two or more wavelengths which have a comparatively large difference between them can be outputted. |
