PURPOSE: To widen the area where a uniform irradiation is attained, by reflecting two beams, which are emitted from both ends of a laser resonator, on mirrors and superposing these reflected beams.
CONSTITUTION: When beams (a) and (a') emitted from both ends of a laser resonator 1 are reflected on mirrors 2 and 2' to irradiate a light receiving face 5, respective beams having Gaussian distributions overlap partially, and a wide area S is obtained as the area having a flat illuminance distribution. For the purpose of preventing interference fringes, a wavelength plate 3 is inserted in the optical path of one beam. If the light receiving face 5 is linear, a cylindrical lens 4 is arranged just before the light receiving face 5 to converge beams. In case of a gas laser 1', two beams (b) and (b') are different in intensity frequently, and therefore, beams are expanded by beams expanders 71 and 71', and a half mirror 30 is used to mix both beams with a transmitted light and a reflected light, and beams are reflected on mirrors 21 and 21' and are superposed after intensities of these beams are equalized in this manner.
MINOURA KAZUO
BABA TAKESHI
MATSUOKA KAZUHIKO
SOMEYA ATSUSHI
