Quad-phase synchronous light detection with 64×64 CMOS modulated light camera

Abstract

A scalable 64×64 array of feedback buffered photodiodes with column level demodulation circuitry has been fabricated in a 0.35 µm CMOS process. The camera provides two-dimensional phase-sensitive imaging on a line-scan basis using 64 independent quad-phase demodulation channels. Using four phases suppresses even harmonics, enabling the array to be used for heterodyne demodulation.