Sensitivity of triangular resonator with long evanescent field around critical angle

摘要

A novel triangular resonator with a long evanescent field around the critical angle has been analysed and demonstrated for the first time. The sensitivity of the resonance shift used for changing the refractive index of 1 × 10~(-5) at the incidence angle of 18° is 1.04 × 10~(-7) nm/ RIU for transverse magnetic polarised light. An extinction ratio of 6 dB was observed near 1550 nm, where the incidence angle of the total internal reflection mirror inside the resonator was 18°.