Light-assisted templated self assembly using photonic crystal slabs

We calculate optical forces on colloidal particles over a photonic crystal slab. We show numerically that exciting a guided resonance mode of the slab yields a resonantly-enhanced, attractive optical force. Optical forces in the lateral direction result in a two-dimensionally periodic pattern of stable trapping positions. Trapping patterns can be reconfigured by changing the wavelength or polarization of incident light. We study the dependence of optical forces on particle size, particle dielectric constant, and photonic-crystal slab parameters. Finally, we describe the fabrication and measurement of a photonic crystal slab with a Q similar to 370.