Real-time tunable incoherent spatial filtering: a two-pupil processing technique

A two-pupil heterodyne scanning system has been used previously to perform bipolar incoherent spatial filtering. In this paper, we exploit the system's potential in tunability. It is shown and verified experimentally that with two offset pupil functions, both having Gaussian shape, we can achieve tunable bandpass filtering operations. Potential applications in space-variant filtering on incoherent objects are discussed.