Loss determination in microsphere resonators by phase-shift cavity ring-down measurements.

Department of Chemistry, Queen's University, Kingston, ON K7L 3N6, Canada.
Optics Express (Impact Factor: 3.53). 09/2008; 16(17):13158-67. DOI: 10.1364/OE.16.013158
Source: PubMed

ABSTRACT The optical loss of whispering gallery modes of resonantly excited microresonator spheres is determined by optical lifetime measurements. The phase-shift cavity ring-down technique is used to extract ring-down times and optical loss from the difference in amplitude modulation phase between the light entering the microresonator and light scattered from the microresonator. In addition, the phase lag of the light exiting the waveguide, which was used to couple light into the resonator, was measured. The intensity and phase measurements were fully described by a model that assumed interference of the cavity modes with the light propagating in the waveguide.

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