Phase response measurement technique for waveguide grating filters

Widely tunable long-period waveguide grating filters

This paper presents a review of the development of long-period waveguide gratings (LPWGs) with focus on the realization of various kinds of tunable devices, such as band-rejection filters, variable attenuators, band-pass filters, and add/drop multiplexers. A number of specific examples are given to demonstrate how the geometry and material flexibility of the optical waveguide technology facilit...

Very narrow spectral filters with multilayered grating-waveguide structures

Promising configurations for grating-waveguide structures are presented. In these structures, the grating layer, which is normally adjacent to the waveguide layer, is displaced by means of an intermediate layer, resulting in significant reduction of losses and weaker coupling. This leads to very narrow spectral bandwidths and high contrast ratios. Experimental results reveal that the spectral b...

Dual spectral filters with multi-layered grating waveguide structures

Promising configurations for dual spectral filters based upon grating-waveguide structures are presented. In these configurations, the parameters of the multimode waveguide and grating are carefully chosen to achieve dual resonances at two different pre-determined wavelengths. Specifically, the grating-waveguide structure resonates for each pre-selected wavelength with a different waveguide mod...

Wavelength response of waveguide volume grating couplers for optical interconnects.

The wavelength response of a waveguide volume grating coupler (WVGC) is analyzed for coupling light from a slab waveguide into the superstrate. A leaky-mode approach is used in conjunction with rigorous coupled-wave analysis. A quantitative theoretical study of the effect of index modulation, waveguide index, and grating thickness on the wavelength bandpass of a WVGC is also presented. The FWHM...

Measurement of the photorefractive grating phase shift in a polymer by an ac phase-modulation technique