Simulations of near-field excitation and trapping for integrated near-field optical microfluidic devices

Simulations of near-field excitation and trapping at 100 nm apertures were conducted to aid design of an integrated near-field optical device for detection and manipulation of molecules in fluidic microchannels. The simulations indicate that optical trapping will occur at near-field aperture edges, and if plane-polarized light is used the trapping edge can be selective. By changing the plane of polarization the position of the trap can be rotated. The near-field apertures have been fabricated inside microchannels using a novel batch micromachining process. The process consists of patterning micron size holes in a silicon nitride membrane, which are then reduced in size through the redeposition of silicon nitride thin films. Nanoholes down to 100 nm in diameter have been fabricated.