Full-field heterodyne interferometry using a complementary metal-oxide semiconductor digital signal processor camera for high-resolution profilometry

We describe a heterodyne interferometry system based on a complementary metal-oxide semiconductor digital signal processor (CMOS-DSP) camera that is utilized for full-field optical phase measurement using a carrier-based phase retrieval algorithm, with no need for electro-mechanical scanning. Camera characterization test results support the adoption of a single-pixel approach to perform quasi-instantaneous differential phase measurements, which are immune to mechanical vibrations and thermal drifts. We developed an optical configuration based on a Mach-Zehnder heterodyne interferometer to perform a static test on a mirror surface. The profiles of the mirror surface set at two angular positions, the relative displacements in the range of nanometers, and the corresponding tilt angle were determined.