DEVELOPMENT OF ADVANCED FAR-INFRARED PHOTOCONDUCTOR ARRAYS

The SIRTF 32x32 Ge:Ga array is the largest format far-infrared array. It is constructed from a stack of 4x32 pixel modules, forming a filled array with no inactive area between pixels. We describe the development of a 64x64 array based on the SIRTF architecture. The array consists of 4x64 modules, each with eight 32-channel cryogenic readouts. The new readout features selectable gains, permitting operation at a variety of backgrounds including those present in airborne observatories like SIRTF. The readout also features an auto-zero circuit that compensates for input threshold variations. We have constructed a 4x64 prototype module, and this device is under test