Optical Engineering • Open AccessPolarization-controlled wavelength modulation by a resonant transmission or reflection filter
A relief diffraction grating is holographically recorded in azo-polymer. The polymer layer under the grating serves as a waveguide for the light coupled by the grating. When a guiding condition is met, sharp minima appear in the transmitted spectrum and sharp maxima appear in the reflected spectrum. Since the resonance conditions for transverse electric (TE) and transverse magnetic (TM) polarized waves occur at different wavelengths, the effect can be used for fast wavelength encoding of a binary signal. The speed of such a device would be limited only by the speed of the encoding part, which changes the azimuth of the input linearly polarized light.