WAVEGUIDE TYPE LASER DEVICE

PURPOSE:To reduce a waveguide loss and facilitate high efficiency oscillation even if the space between facing waveguide walls is narrow by a method wherein, in a hollow waveguide defined by metal electrodes and dielectrics, metal thin film layers and dielectric thin film layers with small absorption are successively laminated on the sides of the hollow region of the facing dielectrics. CONSTITUTION:Material such as Cu which has sufficiently large complex refractive index or complex refractive index whose imaginary part is larger than the real part and high thermal conductivity is employed as the material for metal thin film layer 4 like the material for a metal electrode 1. As material for a thin film 5 with small absorption which is laminated on the metal thin film 4, for instance chemically stable ZnSe or the like is selected and the film 4 is formed by sputtering or vacuum evaporation. A hollow waveguide 3 as a laser discharge passage has a square cross section and dimensions of about 2X2X200mm and facilitate single-mode oscillation and, as its output intensity distribution is close to a circular distribution, the waveguide 3 can be coupled easily with an external waveguide. He, CO2, N2 or mixed gas of He, CO2, N2 and Xe is enclosed in the hollow waveguide 3. A flat total reflective mirror and a partial transmitting mirror are provided at both ends of the hollow waveguide 3 and the laser beam is outputted through the partial transmitting mirror.