| 摘要 |
PURPOSE:To eliminate the polarization dependency of an array waveguide diffraction grating by loading a film (stress imparting film) which has residual stress and varies the birefringence value of a waveguide on the waveguide. CONSTITUTION:On a silicon substrate 3, an input waveguide 4, an output waveguide 6, input- and output-side slab waveguides 51 and 52, the array waveguide diffraction grating 2, and stress inducing film 11 are arranged. On the array waveguide diffraction grating 2 consisting of channel waveguides 21-2i which have the birefringence value B and optical wavelengths Li (i=1, 2, 3...), the stress imparting film 11 which varies the birefringence value of the channel waveguide to B' is loaded. Namely, when the length for which the stress imparting film 11 converts the channel waveguide is Li (i=1, 2, 3...), an equation is satisfied. Namely, the difference in birefringence value generated between the part where the stress imparting film 11 is loaded and other parts is utilized to eliminate the polarization dependency totally. |
