"On chip" Fourier processing to enhance SNR in the presence of background noise

Lockheed Martin's Advanced Technology Center in Palo Alto has developed a prototype 8x8 NIR focal plane capable of simultaneous Fourier processing per pixel. Experiments will be described in which 10 kHz Fourier processed frame rates are used to drive a closed loop tracking servo loop. The pointing direction of one laser with wavelength λ1, and amplitude modulation f1 is adjusted with a fast stirring mirror to track the motion of two targets illuminated by two other lasers with wavelengths λ2 and λ3, amplitude modulated at two other distinct frequencies. Closed loop tracking control at 1kHz is demonstrated using only the single 8x8 focal plane to sense position of the three lasers simultaneously at all pixels. Random noise generated by heat sources and a fan applied to the track laser beam path, and a white light source with 100x larger signal then the received laser signal shown directly on the focal plane, has no effect on the track loop. A final discussion will show the capability of the sensor to simultaneously measure range, as well as position.