Design, Fabrication and Characterization of Optical Nanocavities

Lithography and dry etching enables the microfabrication of distributed Bragg mirrors, photonic crystals, and photonic band-gap structures in many semiconductors. Together with three-dimensional modeling of electromagnetic fields, we use this fabrication capability to define useful optical devices, such as high Q optical nanocavities, optical waveguides and even efficient light emitting diodes. We have recently demonstrated low threshold optically pumped photonic crystal lasers and quantum dot photonic crystal lasers. We experimentally confirm our modeled electromagnetic field distributions in such devices by using near field scanning optical microscopy. The high index contrast available in semiconductor systems enables the miniaturization of optical devices and their integration into compact nanophotonic circuits. Here we present the details of the design, fabrication and characterization of such devices, with a particular focus on optical nanocavities, ultra-small lasers and optical sensors.