| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that it is difficult to obtain an optical modulation part outputting modulation light of a stable polarization state having a sufficient ON/OFF extinction ratio and no time variation in a simple configuration in a coherent laser radar device using the optical modulation part comprising an acoustic optical element. SOLUTION: The optical modulation part 3 used for the laser radar device includes an input and output light separation means 31, an optical modulation means 32 comprising the acoustic optical element 324, and a light entire reflection means 33 making almost entire reflection to output laser light of a reference light source 1. The optical modulation means is composed to be modulated twice by passing input light from the input and output separation means and reflection light from the light entire reflection means. The light entire reflection means has a polarization face rotation function orthogonally rotating the polarization face of emission light to the polarization face of incident light and obtains the modulation light of a stable polarization state having the sufficient ON/OFF extinction ratio and no time variation. COPYRIGHT: (C)2008,JPO&INPIT
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