An all single-mode fiber Michelson interferometer sensor

A Michelson interferometer made from a single-mode fiber directional coupler with silver mirrors deposited on fiber ends is presented. This interferometer is simple to fabricate and has a theoretical visibility of unity, irrespective of the splitting ratio of the coupler. A theoretical analysis of its performance is described. Locking to quadrature was achieved by tuning the frequency of the laser source at 1.52μm. Results are presented for the interferometer operating over one kilometer of single-mode fiber, in a passive remote sensing configuration.