Optical fiber sensing with a low-finesse Fabry-Perot cavity

A detailed comparison between a low-finesse Fabry-Perot cavity and a typical two-beam interferometer is developed and checked experimentally. The consequences of approximating the true Fabry-Perot function by the two-beam function are evaluated for commonly used signal-processing schemes in order to quantify the final error introduced in various fiber sensing schemes employing this configuration.