| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-performance tunable filter having a deep attenuation range and high transmittance. SOLUTION: In the tunable filter, light made incident from a light source or another optical system is made incident on a first optical system 1 and changed to luminous flux parallel with an optical axis. The light is vertically made incident on a first Wollaston prism 2, and then the advancing directions of P polarized light and S polarized light are separated. The light spectrally split by a grating 53 forms two spectrum images of polarized light separation input light beams of the P polarized light and the S polarized light respectively on a first liquid crystal element array 61 and a second liquid crystal element array 62 of the reflection type liquid crystal element array device 6 by a spectroscopic camera optical system 54. By adjusting voltage to be applied to the respective unit liquid crystal elements of the first liquid crystal element array 61 and the second liquid crystal element array 62, the retardation of the respective unit liquid crystal elements is adjusted. Thus, the direction of polarization of the luminous flux reflected from the first liquid crystal element array 61 and the second liquid crystal element array 62 and returning to reversely trace a path where it is made incident is changed for each wavelength of the incident light. COPYRIGHT: (C)2008,JPO&INPIT
|
