Large Format Dual Band FPA ROIC for Low Flux Environments

The Dual Band Compact Hyperspectral Imager (DBCHI) delivers high performance, co-registered medium and long wavelength hyperspectral data from a compact, man-portable sensor. The existing DBCHI dual band focal plane array (FPA) is designed to operate in a broadband tactical flux environment, uses a direct injection input circuit and is not optimal for the minimum flux levels present in the narrowband DBCHI pixel. A redesign of the readout integrated circuit (ROIC) using a capacitive feedback transimpedance amplifier (CTIA) input circuit optimized for low noise and lower flux environments (~1 W/cm2 at the detector) will improve performance of the DBCHI and other low background dual-band imaging sensor systems. On Phase I, Black Forest Engineering (BFE) designed and demonstrated by analysis a low-background dual-band ROIC compatible with the DBCHI and existing HgCdTe detector arrays that will provide improved performance when developed on Phase II. The BFE ROIC is a 640x480 array format with 20 m pixel pitch capable of 60 Hz frame rates with integrate while read, high dynamic range with dark current subtraction and high injection efficiency. Variable signal gain is available between MWIR and LWIR bands and horizontally across the FPA. BFE based the pixel & ROIC design on using dual band sequential (single bump) detector arrays. On Phase II, the ROIC design will be completed (compatible with the existing DBCHI system), ROIC wafers processed, dual band FPAs assembled/tested and FPAs delivered for DBCHI integration.