Deeply Etched Optofluidic MEMS Cavity in a Fibre Ring Laser Configuration for High Resolution Refractive Index Sensing

Abstract

We present an optofluidic MEMS cavity in direct passive and active ring laser configurations for high resolution refractive index sensing. The cavity consists of two curved and slotted Silicon mirrors fabricated by deep reactive ion etching with a submillimetre separation between the mirrors for a fused Silica cylindrical optofluidic channel. The ring laser active configuration demonstrates a sensitivity and figure of merit of more than 5,000 nm/RIU and 25,000 respectively compared to 780 nm/RIU and 260 for the direct passive configuration