| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a variable optical filter in which wavelength and selection band width are independently variable. <P>SOLUTION: Incident light is made incident on a diffraction grating 16 via a circulator 12 and a collimator lens 15. The light reflected on a reflection part 17 is made incident on the diffraction grating 16 again, the light beams dispersed for every wavelength are guided to a reflection part 20 with a lens 19 in the form of parallel belt-like light beams. The light beam which is made incident on the reflection region 20a of the reflection part 20 is emitted via the same path. The wavelength is selected by turning the reflection part 17 and the band width is varied by linearly moving the reflection part 20. <P>COPYRIGHT: (C)2008,JPO&INPIT |
