AN OPTICAL-PHASE AMPLIFICATION TECHNIQUE FOR INTERROGATING FIBER RESONATOR SENSORS

We describe a technique for the effective amplification of small phase changes induced by cavity perturbations of a resonant fiber-optic sen sor. The scheme utilizes an unbalanced two-beam ''read-out'' interfero meter to monitor weak frequency shifts in a laser source locked to the resonant sensor. Results are presented using a fiber ring resonator s ensor and Mach-Zehnder read-out interferometer with a system phase gai n factor of 43.