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 sensor. The scheme utilizes an unbalanced two-beam "read-out" interferometer to monitor weak frequency shifts in a laser source locked to the resonant sensor. Results are presented using a fiber ring resonator sensor and Mach-Zehnder read-out interferometer with a system phase gain factor of 43.<
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