Photodetector Selection Considerations for Large Diameter  Telescope and Stellar 
Intensity Interferometer Arrays.

David Kieda (University of Utah)
 
Future  distributed arrays of large diameter (5-20 m) optical telescopes for VHE  gamma
astronomy  may allow for the revival of the Intensity Interferometry (SII) technique for
high resolution imaging of stellar envelopes and stellar diameters in the U and V bands.
The successful implementation of SII will require measuring correlated fluctuations in 
the arrival times of photons from bright stars between telescopes in the array. The 
technique is expected to provide superior sensitivity to traditional Michaelson  
Interferometry for U/V band observations of bright , hot stars (V<  mag 2-5) .
 
The combination of  bright optical magnitude and large mirror area places severe
constraints on the type of photodetector that may be used to reliably detection the
 II fluctuation correlation. In this talk, I will describe important defining
characteristics of photomultiplier, silicon,  and avalanche photodiode photodetectors for
application to II arrays. In particular, I will discuss the  limitations imposed on the use
of these devices by the unique signal and background environments imposed by the SII 
technique.