| 摘要 |
PROBLEM TO BE SOLVED: To provide a tunable filter that is compact, and large in an amount of emission light.SOLUTION: The tunable filter comprises: a polarization branch section; a wavelength distribution type spectral element; and a reflection type spatial modulation element. The polarization branch section has: a first separation connecting member that has a first branch surface separating incident incidence light into first linear polarizing light as reflection light and second linear polarizing light as transmission light; a first reflection member that has a first reflection surface reflecting the second linear polarizing light; a second reflection member that has a second reflection surface reflecting the first linear polarizing light; and a second separation connecting member that has a second branch surface transmitting the first linear polarizing light reflected upon the second reflection surface, and reflecting the second linear polarizing light reflected upon the first reflection surface. Modulation light of two spectrum images reflected by the reflection type spatial modulation element is made incident upon the wavelength distribution type spectral element and the polarization branch section once again, thereby a wavelength region component modulated by the reflection type spatial modulation element and a non-modulated wavelength region component are separated from each other. |
