Dispersion Engineering with Leaky-Mode Resonant Photonic Lattices

We investigate the dispersion properties of leaky-mode resonance elements with emphasis on slow-light applications. Using particle swarm optimization, we design three exemplary bandpass leaky-mode devices. A single-layer silicon-on-insulator leaky-mode element shows a time-delay peak of similar to 8 ps at the resonance wavelength. A double membrane element exhibits an average delay of similar to 6 ps over similar to 0.75 nm spectral bandwidth with a relatively flat dispersion response. By cascading five double-membrane elements, we achieve an accumulative delay of similar to 30 ps with a very flat dispersion response over similar to 0.5 nm bandwidth. Thus, we show that delay elements based on leaky-mode resonance, by proper design, exhibit large amount of delay yet very flat dispersion over appreciable spectral bandwidths, making them potential candidates for optical buffers, delay lines, and switches. (C) 2009 Optical Society of America