Design and testing of a high-speed, low-noise infrared detector array

For infrared laser remote sensing, a direct detection receiver may be optimally designed around a high speed, low noise focal plane array (FPA). Short pulse, high repetition rate operation of the laser transmitter makes it beneficial to operate the detector with short integration times, lowering the limiting integrated background photon flux. With this photon signal (which constitutes a noise contribution) made small enough, improved low-noise readout integrated circuits (ROIC) can be used to realize a significantly improved imaging lidar receiver. A 10 by 10 pixel ROIC has recently been designed and fabricated. Demonstrated capabilities include >100 kHz frame rate, 50 ns integration time, and less than 100 e(-) of input-referred readout noise. These ROICs have been mated with long-wavelength HgCdTe infrared detector arrays, with cutoff wavelengths greater than 11 mum. Characteristics of the demonstrated ROIC design will be presented, along with testing of the focal plane arrays hybridized to them.