Whispering-gallery mode (WGM) resonators are known to offer outstanding properties for applications in photonics and
telecommunication. Despite their promising performance, one major obstacle for the use of WGM resonators in
industrial products is the need of expensive components and high-precision setups for their operation, requiring a
controlled lab environment. For industrial applications technically simpler and more robust realizations are desired.
Active WGM resonators utilize an optical gain medium for light amplification within the resonator and may be operated
as lasers. They offer several advantages over their passive counterparts, such as cheap pump sources, free space
excitation of resonator modes, and potentially narrower line widths. However, collection of the light emitted from the
resonator still bears several challenges. Emission occurs in plane of the resonator and radiation is emitted isotropically
along the circumference. Thus, detectors positioned in plane of the resonator may collect only a limited angular segment
of the resonator's light emission. We report on a microoptical device which is integrated on the resonator chip and
redirects all in-plane emission of active WGM resonators into a defined off-plane direction. Redirected light can easily
be collected using a standard detector. Contrary to other approaches our microoptical device does not decrease the
quality factor (Q factor) of the resonator. As light from all angular segments of the resonator is collected, the detected
signal-to-noise ratio is expected to be largely improved. Our microoptical device therefore offers a promising approach
towards mass-producible integration of active WGM resonators, e. g. into a Lab-on-a-Chip, for sensor applications,
where smallest possible frequency shifts need to be read out by a highly sensitive detector.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.