Frishauf, Holtz, Goodman & Woodward
Optical system for synthesizing plural light beams
 In an optical system for synthesizing a plurality of light beams, a first light beam of parallel light rays emitted from a laser beam source is incident on an inclined face of a right angle prism through the prism. A second light beam of parallel light rays emitted from a laser beam source is incident to the inclined face at a predetermined angle of incidence. The first light beam is emitted to the inclined face at an angle of incidence equal to a critical angle so that the first light beam is totally inflected by the inclined face and transmitted in a predetermined direction. The second light beam is refracted at an angle of refraction substantially equal to the Brewster's angle, and then transmitted in a direction which defines a predetermined angular difference with the predetermined direction of the first light beam. A multi-layered film is formed on the inclined face. The film makes the angle of refraction of the second light beam approach the critical angle, so as to reduce the angular difference from that which would exist in the absence of the film. 
Olympus Optical Co., Ltd.
G G G G G G G G
G02B G11B G11B G02B G02B G02B G11B G11B
inventional inventional inventional inventional inventional inventional inventional inventional
Masaharu Kiichi
Sakamoto Kato