| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to inexpensively provide a semiconductor polarization control element which is free of optical coupling loss and is variable in wavelength by electrical control by periodically arranging diffraction grating elements having asymmetry in a direction perpendicular to a waveguide direction of light and a direction parallel with a semiconductor substrate into an optical waveguide, thereby constituting a polarization mode converter. SOLUTION: The polarization mode converter is constituted by periodically arranging the diffraction grating elements 1 having the asymmetry in the direction perpendicular to the waveguide direction of light and the direction parallel with the semiconductor substrate 2 in the optical waveguide 1 of the optical semiconductor device. The conversion of the polarized wave of the propagation light is made possible by using such asymmetrical waveguide structure. The constitution of the polarization control function of high efficiency is made possible by imparting periodicity to the structure in such a manner that the conversion process thereof interferes constructively, i.e., by periodically arranging the diffraction grating elements 6 of a length L having the asymmetry. As a result, the semiconductor polarization control element which is free of the optical coupling loss and is variable in the wavelength by the electrical control is inexpensively obtd. |
