To provide a laser beam irradiation device which can irradiates laser beams from low-order mode oscillation laser devices upon a sample while maintaining a uniform intensity distribution by constituting the irradiation device so that the device may introduce laser beam aggregates having nearly parallel optical axes to a laser beam uniformizing optical system and irradiate the laser beam emitted from the optical system upon the sample.
Laser beams 2a-2b from low-order mode oscillation laser devices 1a-1d are respectively introduced to the incident ends of optical fibers 4a-4d by means of incident units 3a-3d. The laser beam which advance in the fibers 4a-4d are emitted from an light emitting end 5 in such a state where the intensities of the laser beams at their central parts are relatively weakened. In addition, since the laser beams emitted from the fibers 4a-4d become aggregates of laser beams 6a-6d having large spreading angles, each laser beam has an expanded diameter and is mixed with the laser beams emitted from adjacent fibers. Thereafter, the laser beams 6a-6d are introduced to a laser beam uniformizing optical system 9 by means of an optical element and irradiated upon a sample 10 in a uniform intensity distribution.
SASAKI HIROHARU
KANEKO YUTAKA
