Loss-compensated photoelastic fiber optic pressure sensor

A fiber optic pressure sensor based on the photoelastic effect has been set up in a four-port polariscope. The down lead insensitivity is achieved by application of the balanced bridge referencing technique. The sensor has an excellent insensitivity to source intensity fluctuations as well as mode dependent and mode independent changes in the damping of the down leads. The sensor exhibits a linearity of +/-0.1% and a temperature stability of +/-1% within a range of 0-60 degrees C with respeat to a span of 6 bar.