Spatial refractive index sensor using whispering gallery modes in an optically trapped microsphere

摘要: The authors propose the use of an optically trapped, dye doped polystyrene microsphere for spatial probing refractive index at any position in a fluid. Using embedded as internal broadband excitation source eliminated need tunable source. They measured full width half maximum and frequency spacing transverse electric magnetic resonances function immersion achieved sensitivity 5×10−4 index, even when exact size was not known.