We propose and analyze a new type of resonator in an annular geometry which is based on a single defect surrounded by radial Bragg reflectors on both sides. Unlike conventional, total internal reflection based ring resonators, this structure supports modal fields with very low azimuthal number (large radial k-vector component). We show that the conditions for efficient mode confinement are different from those of conventional Bragg waveguiding in a rectangular geometry. To realize tight confinement of the light in the defect, chirped gratings are required. Compared to a conventional resonator, the new resonator exhibits larger FSR and lower losses making it suitable for both telecom and sensing applications. In addition, the resonance wavelength and Q factor of the device are very sensitive to environmental changes, and thus provide ideal observables for sensing applications. Annular Bragg resonators with several unique geometries have been fabricated in an InGaAsP multi-quantum-well membrane. The spectral properties of the resonators have been investigated through analysis of photoluminescence induced by pulsed optical excitation.
The Space Infrared Telescope Facility (SIRTF) will be launched in early 2003, and will perform an extended series of science observations at wavelengths ranging from 3.6 to 160 microns for five years or more. The California Institute of Technology has been selected as the home for the SIRTF Science Center (SSC). The SSC is completing the final stages of prelaunch development and testing of the Science Operations System (SOS), which will support science operations of the Observatory. The SOS supports a variety of functions including observing proposal submission by the scientific community, long range planning and short term scheduling of the Observatory, instrument performance monitoring during nominal operations, and production of a variety of scientific archival products. This paper describes the role and function of the SSC, the architecture of the SOS, and discusses the major SOS subsystems. Examples of products generated by the SOS are included