| 摘要 |
<P>PROBLEM TO BE SOLVED: To continuously sweep over a predetermined wavelength band, in a state without mode hopping. Ž<P>SOLUTION: Relating to a wavelength sweep-over light source of external resonator type in the Littman method, a rotating mirror is connected to a frame 31 with a pair of twist-deformable connecting parts 33 and 34, along with a reflecting plate 32 arranged inside the frame, and a force is periodically applied to an end of the reflecting plate 32 so that the reflecting plate 32 is reciprocatively turned about the connection parts 33 and 34. The wavelength swept light source includes a light-receiving unit 60 for receiving zeroth-order diffraction for the light incident on the diffraction plane of a diffraction grating 25 from a semiconductor laser 22; a mode-hop detecting means 61 for detecting a discontinuous change in the output signal of the light receiver 60 that occurs due to mode hopping, while the outgoing optical wavelength of the semiconductor laser 22 is swept by the reciprocative turning of the reflecting plate 32; and an injection current control means 65 for changing the injection current of the semiconductor laser 22 so that the discontinuous change in the output signal of the light receiving unit 60 due to mode hopping disappears. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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