| 摘要 |
PURPOSE: To improve the wavelength selectivity of mode conversion by constituting, an optical function device in such a manner that respective electrodes are changed in arranging density along a light propagation direction. CONSTITUTION: A mode converter 1 is composed of a substrate 11 of an electro- optical material, an optical waveguide 1, a pair of comb-shaped electrodes 14, 15 for impressing electric fields to the optical waveguide 12 and a buffer layer 13. The arranging spacings of electrode fingers 14a, 15a are set in compliance with a Hamming function in a mode converter 1 and, therefore, the electric field distribution of the density decreasing gradually from the central part to the end of the light propagation direction is generated in an optical waveguide 12 when bus cylindrical body parts 14b, 15b are connected to a power source for outputting a specified voltage. The light propagating in the optical waveguide 12 is rotated in the polarization direction by the angle meeting the intensity of the electric fields by passing the electric fields. As a result, mode conversion is realized between a TE mode and TM mode for light of the selected wavelength if the impression voltage is set according to the electrode length L of the comb-shaped electrodes 14, 15. |
