Modeling of the influence of coupling in optical microfiber resonators.

By modifying the resonance condition of optical microfiber resonator while considering the strong coupling effect, we theoretically investigate the influence of coupling on the resonant wavelength and refractive index sensitivity, and compare our results with the previously published results. Numerical calculation shows significant difference in resonant wavelength and sensitivity for different coupling strengths. By considering coupling effect, the resonant peak position can be shifted as far as 3.89 nm and the sensitivity can be modified by as much as 83 nm/RIU. This suggests a method to tune the resonant wavelength and sensitivity, by varying the pitch and the coupling between two adjacent microfibers in the coupling area.