Engineering light using large area photonic crystal devices

Abstract

Photonic crystals are fabricated structures composed of a periodic arrangement of materials with differing indices of refraction. This research has focused on the realization of two distinct photonic crystal structures in which large area has played a key role: 1) large area broadband saturable Bragg reflectors, and 2) large area 2D photonic crystal devices. Saturable Bragg reflectors (SBRs) can be used to self-start ultra-short pulse generation in a variety of solid state and fiber lasers. To form shorter pulses, SBRs with broadband reflectivity and large area (100's of [mu]m) are required. This thesis describes the design and fabrication of large area broadband saturable Bragg reflectors through the monolithic integration of semiconductor saturable absorbers with large area broadband Bragg mirrors. One of the key elements for realizing this device is the development of a wet oxidation process to create buried low-index ... layers over large areas. Large area 2D photonic crystals enable new methods for routing and guiding light with applications in compact integrated optical circuits. This research has explored the design and fabrication of two large area (centimeter-scale) 2D photonic crystal devices: a superprism and a super- collimator.

(cont.) A superprism is a photonic crystal device in which the direction of light propagation is extremely sensitive to the wavelength and angle of incidence. A super- collimator is a device in which light is guided by the dispersion properties of a photonic crystal slab without boundaries which define the light's path. Design, fabrication, and testing are discussed for both 2D photonic crystal devices.