In this paper a method of taking widefield heterodyne inter- ferograms using a prototype modulated light camera is described. This custom CMOS modulated light camera (MLC) uses analogue quadrature demodulation at each pixel to output the phase and amplitude of the modu- lated light as DC voltages. The heterodyne interference fringe patterns are generated using an acousto-optical frequency shifter (AOFS) in an arm of a Mach-Zehnder interferometer. Widefield images of fringe patterns acquired using the prototype MLC are presented. The phase can be measured to an accuracy of ±6.6◦. The added value of this method to acquire widefield images are discussed along with the advantages.
Patel, R., Achamfuo-Yeboah, S., Light, R., & Clark, M. (2011). Widefield heterodyne interferometry using a custom CMOS modulated light camera. Optics Express, 19(24), doi:10.1364/OE.19.024546