Abstract

Microsphere resonators are unsurpassed in terms of their ability to confine light for relatively long durations and within small modal volumes. These properties make high-Q microspheres ideally suited for studies of nonlinear physics within a resonant system. Early work by Chang and Campillo [1] demonstrated Raman oscillation in micro-droplets of CS₂ at a record-low pump-power level. However, micro-droplets are not suitable for long term fundamental studies (and practical devices). In this work, we report on the observation of ultra-efficient Raman oscillation in a high-Q microsphere with record low pump threshold in the microwatt range and differential quantum efficiency of 36% [2]. The combination of a high-Q silica microresonator and fiber-taper coupling [3] results in a highly efficient system coupled directly to an optical fiber. As such, this system may naturally lend itself to further studies of the physics of nonlinear systems especially where ultra-low loss is a critical requirement.

© 2002 Optical Society of America