| 摘要 |
PURPOSE:To obtain an optical modulator which modulates light by light by combining an optically active material contg. a functional group which exhibits a photochromic phenomenon in the molecule and polarizers. CONSTITUTION:A soln. 3 prepd. by dissolving the optically active material in methanol is sealed in a quartz cell 3a and the light from a light source 1 such as He-Ne laser light is made incident on the soln. 3 via the polarize 2a. The soln. 3 is irradiated with the UV rays from a light source for modulation consisting of a band-pass filter 5 which allows the transmission of UV rays and a UV lens. A change arises in the degree of rotatory polarization of the optically active material by reflecting the structural change of the azobenzene when the azobenzene is isomerized from a trans type to cis type by the irradiation of said UV light. The light from the light source 1 transmitted through the soln. 3 is detected by a photodetector 7 via the polarizer 2b. The reverse reaction from the cis type to trans type is further induced and the original degree of rotatory polarization is restored when visible light is further irradiated thereto.
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