RESONANT GRATING WAVE-GUIDE STRUCTURES FOR VISIBLE AND NEAR-INFRARED RADIATION

A new ray picture model based on the multiple interference of light wa ves in dielectric resonant grating-waveguide structures is presented. The model clearly elucidates the phase relationship between the incide nt plane wave and the waves diffracted from the resonant grating struc ture that is responsible for the interference of these waves. As a res ult of this interference process the incident wave can be totally refl ected at a certain wavelength and orientation angle. The model is used to describe and analyze this resonance behavior of the grating-wavegu ide structures as a function of wavelength and incidence angle. The an alysis is verified experimentally with semiconductor (InGaAsP/InP) str uctures at wavelengths of 1.55 mu m and also with dielectric (silicon nitride/SiO2) structures at wavelengths of 0.6 mu m. All of the struct ures were formed by electron beam lithography and chemical vapor depos ition. The measured results reveal that subnanometer resonance bandwid ths and finesses as large as 6000 can be achieved at contrast ratios o f 50 with relatively compact structures. (C) 1997 Optical Society of A merica.