Ultrasensitive, Wideband Laser Warning Receiver

This SBIR project will develop a compact, low-cost, ambient temperature operating and ultra-sensitive, wideband laser warning receiver (LWR) based on an ultrasensitivie wavelength dispersive photoreceiver array operating in the 0.4 - 2.5mm wavelength range for shipboard detection of laser threats. We will accomplish this by developing novel ultrasensitive wavelength dispersive avalanche photodiode (APD) detector arrays having low noise, high quantum efficiency and wide-spectral response with each array pixel able to discriminate among wavelengths and angles of arrival of incoming laser signals. In Phase I, we will demonstrate on a single wafer, sub-nanowatt sensitivity, 1-GHz bandwidth detectors with spectral resolution as low as 10-nm at 0.6 um, 0.85 um, 1.1-um, 1.5 um and 2.5 um at room ambient temperature, and show that these detectors can be fabricated as a large format array. In Phase II, we will optimize the detector material and device designs to enable detector pixels with wavelength response varying from 0.4 to 2.5 um. We will then design and fabricate 256 x 256 LWR arrays with 0.1 nW sensitivity equivalent to an irradiance sensitivity of 0.1 mW/cm2 and probability of detection of 90% or one false alarm per hour, as well as a spectral resolution of 10-nm and an angular coverage of 90o.