Interference approach applied to dual-grating dielectric resonant grating reflection filters

The resonant mechanisms associated with dual-grating dielectric resonant gr ating reflection filters are described by use of an interference approach. These structures consist of two modulated regions of equal period separated by a higher-index film region. We show that the spectral linewidth is depe ndent on the separation between the modulated regions and can range from th eoretically zero to approximately four times what would be obtained by use of a single-grating geometry. (C) 2001 Optical Society of America.