An active mode image sensor for optical non-uniformity correction (NUC) of an active mode sensor uses a Micro-Electro-Mechanical System (MEMS) Micro-Mirror Array (MMA) having tilt, tip and piston mirror actuation to form and scan a laser spot that simultaneously performs the NUC and illuminates the scene so that the laser illumination is inversely proportional to the response of the imager at the scan position. The MEMS MMA also supports forming and scanning multiple laser spots to simultaneously interrogate the scene at the same or different wavelengths. The piston function can also be used to provide wavefront correction. The MEMS MMA may be configured to generate a plurality of fixed laser spots to perform an instantaneous NUC.