A fiber-delivered probe suitable for CARS imaging of thick tissues is practical. A second laser beam which has been deflected by a second galvanometer-mirror system, transmits through a polarized beam mixers and is incident upon the first galvanometer-mirror system and the f lens, and accordingly, the workpiece is drilled simultaneously at two positions with the use of both first and second laser beams. When the distance between the thermistor resistor 106 and the light reflecting film 104 is d, a light component having a wavelength expressed by d=l4 and equal to or smaller than l resonates and changes to heat, and the temperature of the thermistor resistor 106 rises. If the traveling direction is to be reversed, a stop is used to block the rear end in order to keep the leading edge of the ingested folded material from leaving the turn chute through the rear end.