| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a method of optical modulation with large modulation efficiency and an optical modulator by modulating light in the maximum absorption wavelength region of a nonlinear optical material. SOLUTION: Light is modulated in the maximum absorption wavelength region of a nonlinear optical material. The maximum absorption wavelength region is determined by the structure of a nonlinear optical material, and a wavelength region shorter than the cutoff wavelength of the material is used. The light is modulated by allowing the light to enter in a film thickness direction of the nonlinear optical material. As for the transmission type modulation method (a), the light propagates once in the nonlinear optical material. In the optical modulation method (b) using the reflected light from a reflection film, the light propagates twice in the nonlinear optical material, which improves the modulation efficiency. As for the reflection film, the metal film such as aluminum gold and copper, dyes or the like having difference in a refractive index from a transmission medium can be used. As for the nonlinear optical material, any material can be used as far as electron donating functional groups and electron withdrawing functional groups are connected by an electron resonance system. The electron resonance system consists of one or more cyclic unsaturated groups and/or unsaturated groups.</p> |
