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We present the development of a near infrared image intensifier tube based on a Generation III configuration. The photocathode driving this tube is based on a negativeelectron-affinity (NEA) InGaAs design. The surface and crystalline quality of the InGaAs active layer for this device is characterized by x ray diffraction (XRD), micro-Raman spectroscopy, energy dispersive x-rays (EDX), and Auger spectroscopy. Room temperature and 77K photoluminescence (PL) and transmission measurements indicate the near infrared responsivity (1 .2-1 .7 tm) of the InGaAs active layer. Reflection mode measurements of the photoresponse (PR) in an ultra high vacuum environment produced white light sensitivities of 100 .tA/1umen and quantum efficiencies of -1% for wavelengths of 1300-1 600 nm at 300 K. Sealed image tubes were created, and early sealed tube results show low quantum efficiencies ('-0. 1% @ 1 550 nm) due to nonoptimized active layer thickness.

A hybrid photodetector based on a Gen 3 photocathode and electron-bombarded silicon, non-pixilated, position sensitive, Avalanche Photo Diode (APD) is being developed. The device promises gains of over 10 6 and sub-millimeter spatial resolution. Signals read at the output of the device can be used to build up images, integrated over the time scales relevant to the process being studied. This integration as a post-process allows significant flexibility in investigation at very low light levels. A design and fabrication process is being developed that can be readily adapted for fastturnaround proof-of-concept prototypes using a variety of solid state detectors. This process approach also facilitates the parallel development of high Quantum Efficiency (QE), low dark count III-V based photocathodes with a broad range of spectral response from UV to NIR. The Imaging Hybrid Avalanche Photo Diode (IHAPD) is targeted to bioluminescence, chemoluminescence and other low light level spectral imaging. A discussion of a reflection mode hybrid APD development is included as well.

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