Optical thin film, optical thin film attaching substrate and laser device

摘要

PURPOSE: To provide the optical thin film optimum as an output mirror of a laser device which make highly repetitive oscillation, an optical filter for shaping the intensity distribution of a laser beam, etc., and the laser device constituted by using this optical thin film. ;CONSTITUTION: This optical thin film is constituted by constituting one of the thin films, exclusive of the uppermost layer and the lowermost layer, of the plural thin films formed on a substrate, of a thin film having an optical film thickness distribution. The reflectivity distribution from the central part to the peripheral edge of the optical thin film is provided with a gaussian distribution by adequately selecting the optical film thicknesses of the other thin films. In addition, the min. reflectivity in the part corresponding to the skirt of the gaussian distribution is higher than the surface reflectivity of the substrate. The arbitrary setting of the reflectivity distribution is possible and the electric field intensity distribution within the thin films and at the boundaries of the thin films is easily decreased. The optical thin film usable as the laser device which can efficiently oscillate the laser beam of good mode patterns with high repetitions, the optical filter for shaping the intensity distribution of the laser beam, etc., and the laser device constituted by using this optical thin film are thus obtd.;COPYRIGHT: (C)1994,JPO&Japio