Nanowire Photonic Devices
M. Loncar, C. J. Barrelet, J. Bao, H. G. Park, C. M. Lieber,
F. Capasso (Harvard)

a) Schematic of Cadmium Sulphide (Cd S) nanowire light-emitting device patterned with one-dimensional Bragg mirrors. (b) Experimental realization in CdS nano-ribbon and (c) in CdS nanowire using focused ion beam processing; (d) CdS nanowire embedded in a silicon nitride photonic crystal slab. Silicon nitride is deposited on a silicon chip; then CdS nanowires are placed on the chip and are then capped with a top layer of silicon nitride. (e) Photonic band diagram for the silicon-nitride photonic crystal slab. The photonic band gap (PBG) strongly confines light to the wire, reducing the laser threshold and achieving extremely narrow divergence. In this way the light emitted from the nanowire can be guided around the chip, making possible future generations of planar light wave-guiding circuits.