Polarization-independent optical wavelength selective coupler.

摘要

A double-periodic grating is described for obtaining polarization- independent filtering and coupling. The grating may be viewed as a combination of two gratings with slightly different grating periods. The two periods are carefully chosen to match the difference in propagation constants of the TE and TM polarization modes such that both modes are coupled at the same wavelength. A novel method of obtaining a double-periodic grating is described. Use in optical waveguide vertical couplers and filters is described.