Resonant optical circuits based on coupling between whispering gallery modes in dielectric microresonators

Abstract

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. The project was devoted to advancing understanding of the optical properties of mesoscopic systems of coupled spherical cavities. Using numerical modeling, we studied optical coupling between spherical cavities with detuned whispering gallery mode (WGMs) resonances. The results were found to be in agreement with experiments performed on size-mismatched bispheres with controllable inter-cavity gaps. We observed new type of optical modes, termed "nanojet-induced modes", in straight chains of microspheres. Due to subwavelength sizes of the periodically focused spots and small propagation losses (<0.1dB/sphere) these modes were shown to be very promising for developing novel devices. The 3D lattices of closely Resonant Optical Circuits Based on Coupling Between Whispering Gallery Modes in Dielectric MicroresonatorsReport Title ABSTRACTThe project was devoted to advancing understanding of the optical properties of mesoscopic systems of coupled spherical cavities. Using numerical modeling, we studied optical coupling between spherical cavities with detuned whispering gallery mode (WGMs) resonances. The results were found to be in agreement with experiments performed on size-mismatched bispheres with controllable inter-cavity gaps. We observed new type of optical modes, termed "nanojet-induced modes", in straight chains of microspheres. Due to subwavelength sizes of the periodically focused spots and small propagation losses (<0.1dB/sphere) these modes were shown to be very promising for developing novel devices. The 3D lattices of closely packed spherical cavities were synthesized by flow-assisted self-assembly with the thickness well controllable up to 100 monolayers. By analogy with the percolation theory we argued that by selecting more uniform spheres it should be possible to achieve an optical percolation threshold for WGM-related transport in such systems. Along with dielectric microspheres we studied GaAs/AlGaAs pillar microcavities where we observed WGMs with Q-factors up to 20000 and small modal volumes. The results of this project are important for developing microprobes for biochemical sensing with subwavelength spatial resolution, reconfigurable filters, sensors and single photon sources.