To obtain a ultra-lightening device capable of obtaining a clear image by inserting a coherence lowering element in an optical pass of laser beam and irradiating an object with the laser beam lowered in coherence.
Light flux emitted from a laser source 10 and passed through an incident lens 14 is lowered in coherence by the coherence lowering element 11 to make the optical intensity distribution flat. The light flux emitted from the coherence lowering element 11 is made incident on a conical external reflection mirror 8 to be reflected radially at 360° in the vertical direction. The radially reflected light flux is reflected in the horizontal direction by a conical internal reflection mirror 9 to be converted to ring like light. The light flux converted to the ring like light is reflected in the direction of an objective lens 3 through a light transmitting plate 7 by a circular flat mirror 13 and further reflected by a conical internal reflection mirror 3a to ultra-irradiate the object 2 over 360° from the outside of the objective lens 3.
IMURA YASUYUKI
ISHIZAKA MASAKI
KOBAYASHI HIRONORI
NAKAMOTO HIROYUKI
OKADA NORIHIRO
