The guided-mode resonance properties of planar dielectric waveguide gratings are presented and explained. It is shown that these structures function as filters producing efficient exchange of energy between forward and backward propagating diffracted waves with smooth lineshapes and arbitrary filter linewidths. Simple expressions based on classical slab waveguide theory give a clear view and quantification of the inherent TE/TM polarization separation and the free-spectral ranges of the filters. Furthermore, the resonance regimes, defining the parametric regions of the guided-mode resonances, can be directly visualized. It is shown that the linewidths of the resonances can be controlled by the grating modulation amplitude and by the degree of mode confinement (refractive-index difference at boundaries). Examples presented of potential uses for these elements include a narrow-line polarized laser, tunable polarized laser, photorefractive tunable filter, and an electro-optic switch. The guided-mode resonance filter represents a basic new optical element with significant potential for practical applications.

Date Published: 2 March 1993
PDF: 12 pages
Proc. SPIE 1732, Holographics International '92, (2 March 1993);

Published in SPIE Proceedings Vol. 1732:
Holographics International '92
Yuri N. Denisyuk; Frank Wyrowski, Editor(s)