Optical characteristics of triangular microresonator with long evanescent field on the total internal reflection mirror

摘要

We investigated the properties of a triangular microresonator using the total internal reflection (TIR) mirrors with a long evanescent field around the critical angle. For the sensitivity analysis, we have calculated the mirror offset due to the Goos-Hnchen effect and the resonance shift of the triangular resonator with the refractive index change of the outer region in the TIR mirror. The mirror offset is increased up to 0.8 μm for the transverse electric (TE) polarization and 2.0 μm for the transverse magnetic (TM) polarization to the incident angle of 18°. Then, the resonance shift of 417 pm for the TM polarized light and 34 pm for the TE polarized light were observed, respectively, by changing the refractive index of 4×10-5. The measured extinction ratio of triangular ring resonator was about 6 dB near 1550 nm, in where the incidence angle of the TIR mirror inside the resonator was 18°.