| 摘要 |
PURPOSE:To permit selection of a specified wavelength and to permit also transformation from TE mode to TM mode optionally by prepg. a relief type diffraction grating having periodicity on the surface of an optical waveguide, coating liquid crystals thereon, depositing Al vapor, and interposing the product between glass plates. CONSTITUTION:An optical waveguide 1 is formed by an ion exchange process on the surface of a glass substrate 3 having a rear surface deposited with Al vapor. A photoresist is coated on the front surface, and a diffraction grating pattern of the resist is formed by the interferential exposure after baking the coated photoresist. The formed diffraction grating pattern is masked, and relief type diffraction grating having each specified period and depth is formed on the surface of the optical waveguide by dry etching. Nematic liquid crystals are poured on the surface of the relief type diffraction grating after providing spacers, then the surface is interposed between glass plates 5 having surfaces deposited with Al vapor. By this constitution, an optical waveguide permitting selective transmission of light having a specified wavelength, permitting also optional transformation from TE mode to TM mode is obtd. |
