| 摘要 |
<p>A light-transmissive solid material, planes formed in the solid material and facing substantially parallel to each other, and a wavelength filter for periodically selecting the wavelength determined by the optical path length between the planes facing each other by performing resonance between the planes facing substantially parallel to each other. The solid material is a doubly refracting material and the optical axis thereof has a predetermined angle with respect to the normal to the planes facing substantially parallel to each other. Thus, the temperature characteristic of the wavelength filter can be freely set, and an arbitrary wavelength characteristic can be selected by changing the temperature of the wavelength filter.</p> |
