INFRARED LASER LIGHT SOURCE

PROBLEM TO BE SOLVED : To visualize the irradiation position of an invisible infrared laser by a simple method. SOLUTION : An optical fiber 5 containing an added rare earth element is used as a light-emitting medium causing excitation level absorption. Exciting light laser is made to come into the optical fiber 5 containing the rare earth element to generate infrared laser and visible photoluminescence. Meanwhile, at the output side of an infrared laser light source, a resonator mirror 7 transmitting visible light is arranged. The generated infrared laser and visible light have identical light passage, thus the visible light, emitted with the infrared laser simultaneously, clearly indicates the irradiation position of the infrared laser.