Hui CaoAdjunct Professor (joint with Yale University) PhD, Stanford University, 1997 Alfred P. Sloan Fellow David and Lucille Packard Fellow Winner, NSF CAREER Award 2006 Maria Goeppert-Mayer Award Cao Research Page Hui Cao's principal research interest is optical processes in nano-structures. Her current research is focused on two areas. The first area involves the investigation of photon localization and coherent light generation in active random media. Cao has demonstrated lasing with coherent feedback in semiconductor nano-powder and nano-crystalline films. In contrast to traditional laser cavities that are made of mirrors, the laser cavities in disordered materials are "self-formed" by light scattering. Cao also utilizes optical scattering for the fabrication of microlasers. A microlaser is a laser whose size is on the order of an optical wavelength. The main challenge in the fabrication of microlasers is to confine light in a micrometer-sized volume. Cao and her collaborators have invented a new type of microlaser that is made of disordered media. Optical confinement is realized through multiple scattering and wave interference. Cao's second area of research is semiconductor microcavity lasers. Cao and a collaborator at Stanford University have embedded semiconductor quantum dots in microdisk cavities. They intend to control single quantum-dot spontaneous-emission processes by using a high-quality microdisk cavity. She is also investigating microcavities with novel shapes in order to control the lasing process and output directionality. Cao has utilized planar microcavities to enhance the nonlinear optical processes in organic materials. The third area of Cao's research is ultraviolet (UV) photonic crystal light sources. Photonic crystals are periodic structures with allowed and forbidden bands for light propagation. The photonic band and gaps can be utilized to reduce the threshold of UV lasers and to increase the efficiency of UV light emitting diodes. Cao, with her collaborator in the Department of Materials Science and Engineering, has developed various techniques to fabricate two-dimensional and three-dimensional photonic crystals using the wide-band-gap semiconductor ZnO. They recently realized the first UV photonic crystal laser in photonic crystal slabs under optical pumping. Selected Publications A. Yamilov, X. Wu, X. Liu, R. P. H. Chang, and H. Cao Self-Optimization of Optical Confinement in an Ultraviolet Photonic Crystal Slab Laser Physical Review Letters 96, 083905 (2006) H. Cao Review on Latest Developments in Random Lasers with Coherent Feedback J. Phys. A: Math. Gen. 38, 10497 (2005) K. Seal, A. K. Sarychev, H. Noh, A. Yamilov, V. M. Shalaev, Z. C. Ying, and H. Cao Near-Field Intensity Correlations in Semicontinuous Metal-Dielectric Films Physical Review Letters 94, 226101 (2005) |