| 摘要 |
PROBLEM TO BE SOLVED: To improve S/N ratio of a laser beam from a row array laser light source while ensuring the intensity of return light from an object by suppressing the diffusion thereof and reducing a beam diameter in a region from the optical path separating member to the laser beam exit window. SOLUTION: A laser beam sending lens 16 collimates the laser beam emitted from a light source unit 3, and the collimated beam irradiates a scan mirror with the diameter of the beam being reduced. There are arranged, from the light source unit 3 side, a collimating lens 52 having positive power, a first cylindrical lens 53 having positive refractive power in the direction orthogonal to the junction surface of a semiconductor laser light source constituting the light source unit 3, a second cylindrical lens 54 having negative refractive power in the direction orthogonal to above-mentioned junction surface, and a third cylindrical lens 55 having positive refractive power in the direction parallel to above-mentioned junction surface in this order. Two cylindrical lenses 53, 54 constitute a beam expander. COPYRIGHT: (C)2005,JPO&NCIPI
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