Multispectral phase imaging based on acousto-optic filtration of interfering light beams [Invited].

Acousto-optic spectral selection of light is an effective technique for interference imaging at multiple wavelengths. In this paper, we show that, depending on the location of the acousto-optical tunable filter relative to the interferometer, it is possible to enhance important characteristics of the whole system: spectral contrast, insensitivity to ambient light, performance stability, and measurement accuracy. We analyze theoretically and compare experimentally a quantitative phase imaging system based on a Mach-Zehnder interferometer with one and two acousto-optical filters located in the illumination or/and in the output channels.