There is a strong demand for portable systems that can detect and characterize individual pathogens and other nanoscale objects without the use of labels, for applications in human health, homeland security, environmental monitoring and diagnostics. However, most nanoscale objects of interest have low polarizabilities due to their small size and low refractive index contrast with the surroundin...

Microdisks fabricated with III-nitride materials grown on GaN substrates are demonstrated, taking advantage of the high material quality homoepitaxial films and advanced micro-fabrication processes. The epitaxial structure consists InGaN/GaN multi-quantum wells (MQWs) sandwiched between AlGaN/GaN InAlN/GaN superlattices as cladding layers for optical confinement. Due to lattice-matched growth l...

We report an experimental observation of strong variations of quality factor and mode splitting among whispering-gallery modes with the same radial order and different azimuthal orders in a scattering-limited microdisk resonator. A theoretical analysis based on the statistical properties of the surface roughness reveals that mode splittings for different azimuthal orders are uncorrelated, and v...

The bound state structure and dynamics for an atom trap formed from the whispering gallery modes ~WGMs! of a dielectric microsphere are investigated. The coupling of the quantized internal and external atomic degrees of freedom plays a fundamental role in the quantum dynamics of this atom gallery. The radiative processes for a cold atom near a microsphere are modified due to the special symmetr...