Competence Center for Specialty Optical Fibers

A Fabry-Pérot cavity of simple design and based on a pure silica diaphragm-free hollow tube is proposed. Its operation is based on a first reflection of light at the end of the single mode fiber that illuminates the silica rod and in a second reflection that takes place at the end of the rod. The Fabry-Pérot cavity is characterized for high temperature, pressure and refractive index sensing, showing useful characteristics for the measurement of these three parameters. The diaphragm-free configuration simplifies the measurement of refractive index of fluids.