Silicone Rubber Based Highly Sensitive Fiber-Optic Fabry-Perot Interferometric Gas Pressure Sensor.

A simple, compact, and highly sensitive gas pressure sensor based on a Fabry-Perot interferometer (FPI) with a silicone rubber (SR) diaphragm is demonstrated. The SR diaphragm is fabricated on the tip of a silica tube using capillary action followed by spin coating. This process ensures uniformity of its inner surface along with reproducibility. A segment of single mode fiber (SMF) inserted into this tube forms the FPI which produces an interference pattern with good contrast. The sensor exhibits a high gas pressure sensitivity of -0.68 nm/kPa along with a low temperature cross-sensitivity of approximate to 1.1 kPa/degrees C.