Dynamic low-coherence interferometry using a double Fizeau cavity.

Abstract

The coexistence of anti-vibration and a common optical path is difficult to realize in dynamic Fizeau interferometry. To address this problem, we propose a dynamic low-coherence interferometry (DLI) using a double Fizeau cavity. The DLI method is a new optical model that creatively renders both surfaces of the RM to interfere with the test surface, utilizing a low-coherence source and optical path matching to construct the common-path p-polarized Fizeau cavity (p-FC) and carrier-frequency s-polarized Fizeau cavity (s-FC). The relative tilt phases of the s-FC are calculated using the carrier frequency interferograms; then the final phase is retrieved with the relative tilt phases and p-FC interferograms. The experimental results demonstrate that the DLI method can provide high-precision phase measurement in a vibration environment.