Compact Heterodyne Pinhole Point-Diffraction Interferometer with High Repeatability and Adjustable Contrast Based on Dual-Cascaded Acousto-Optic Modulators
Conventional pinhole point-diffraction interferometers (PPDIs) owe their popularity to a simple configuration, but that same configuration limits both the usable measurement aperture and the load the phase shifter can carry. Here, we propose a heterodyne phase-shifting point-diffraction interferometer (HPDI) based on d...