| 摘要 |
PURPOSE:To obtain a simple structure having no movable part, by arranging the liquid crystal whose refractive index varies with an applied voltage between two interference mirrors of a Fabry-Perot pair. CONSTITUTION:For example, a nematic liquid crystl 13, whose refractive index is varied by an electric field is held between the interference mirrors 10a and 10b. The outer surface of the crystal is enclosed by a nonconductive spacer 14. A power source 15, which controls the electric field that is applied to the liquid crystal 13, is connected to thin films 12a and 12b. A temperature sensor 16 is incorporated in the vicinity of the liquid crystal part and the temperature is displayed 17. At the rear of the Fabry-Perot pair 10, an observing system is arranged. Light to be checked L which is linearly polarized by a polarizer 19 is inputted into the Fabry Perot pair 10 including the liquid crystal, and reflected by reflecting surfaces 11a and 11b of the interference mirrors 10a and 10b in a multiplex mode. Thus, an interference phenomenon is yielded. |
