Patent ID: 6597839
Filing Date: 2003-07-22
Classification: G02B

Abstract:
An optical system comprising:an optical device for passing light in a predetermined wavelength range, having substantially unequal output orthogonal polarizations for light launched into the device within said wavelength range; and a waveguide having a longitudinal optical axis, the waveguide having a blazed grating therein having a blaze angle &thgr;b1 of 45Â°Â±25Â° with respect to the optical axis of the waveguide, the blazed grating exhibiting a tap efficiency difference for orthogonal polarizations for offseting and lessening a polarization dependence of the device, the waveguide being optically coupled with the optical device, and the grating being oriented about its optical axis to lessen the inequality in output orthogonal polarizations for light launched into the optical device, the blazed grating having index variations within predetermined limits, the predetermined limits such that index variations within the grating are at least 25% of the maximum index variation.