Resonant-grating lineshapes are compared with results from a previously derived approximate coupled-mode analysis [J. Opt. Soc. Am. A 14, 629 (1997)] and to rigorous coupled-wave analysis. Tunability in resonant position (wavelength and angle) and lineshape is achieved by a novel method involving immersion of a bare resonant-grating structure in various liquids, each with a different refractive index. A comparison is made of different filter features—resonant position, efficiency, and angular width—in the experimental results and the theoretical models. The use of coupled-mode theory allows an intuitive picture to be associated with the observed trends in filter characteristic versus refractive index. This investigation reinforces the idea that the use of coupled-mode theory for resonant-grating analysis can simplify filter design.
© 1998 Optical Society of America
(050.1970) Diffraction and gratings : Diffractive optics
(050.2770) Diffraction and gratings : Gratings
(120.2440) Instrumentation, measurement, and metrology : Filters
(230.7390) Optical devices : Waveguides, planar
Scott M. Norton, G. Michael Morris, and Turan Erdogan, "Experimental investigation of resonant-grating filter lineshapes in comparison with theoretical models," J. Opt. Soc. Am. A 15, 464-472 (1998)