Cavity QED treatment of scattering-induced efficient free-space excitation and collection in high-Q whispering-gallery microcavities
arXiv:1206.2426 · doi:10.1103/PhysRevA.85.013843
Abstract
Whispering-gallery microcavity laser possesses ultralow threshold, whereas convenient free-space optical excitation and collection suffer from low efficiencies due to its rotational symmetry. Here we analytically study a three-dimensional microsphere coupled to a nano-sized scatterer in the framework of quantum optics. It is found that the scatterer is capable of coupling light in and out of the whispering-gallery modes (WGMs) without seriously degrading their high-Q properties, while the microsphere itself plays the role of a lens to focus the input beam on the scatterer and vice versa. Our analytical results show that (1) the high-Q WGMs can be excited in free space, and (2) over 50% of the microcavity laser emission can be collected within less than . This coupling system holds great potential for low threshold microlasers free of external couplers.
10 pages, 8 figures
References in corpus (6)
- Cavity QED with Diamond Nanocrystals and Silica Microspheres
- Combining directional light output and ultralow loss in deformed microdisks
- Controlled coupling of counterpropagating whispering-gallery modes by a single Rayleigh scatterer: a classical problem in a quantum optical light
- Chaos-assisted directional light emission from microcavity lasers
- Coupling of a Single Diamond Nanocrystal to a Whispering-Gallery Microcavity: Photon Transportation Benefitting from Rayleigh Scattering
- Collimated directional emission from a peanut-shaped microresonator