| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an optical device using a liquid crystal device as an optical switch with the efficiency significantly improved in such an optical device that is excited only by the intensity of light without using an electric field or current but can control the light, that has a high-quality display function with a high contrat ratio, that can be made a large screen, and that can perform integrated light emission operation. SOLUTION: The device has an optical waveguide (optical fiber) 1, a transparent substrate 2 crossing the optical waveguide (optical fiber) 1, and a liquid crystal device 3 disposed in the crossing part of these. The liquid crystal device 3 has a ferroelectric liquid crystal with <=30.6 deg. pretilt angle. A grating havingλ/8.7774 depth (λis the wavelength of the guided light) is formed on the face of the transparent substrate 2 where light exits. The difference between the effective refractive index of the liquid crystal device 3 during keeping the switch on and the refractive index of the optical waveguide 1 is <=0.064.</p> |
