An evaluation of the new compact hybrid photodiodes R7110U-07/40 from Hamamatsu in high-speed light detection mode

The main parameters of hybrid photodiodes (HPD) are constantly improving. In the new 20 mm diameter HPDs from Hamamatsu an avalanche diode (AD) serves as anode. Due to high gain of the used ADs the HPDs show a total gain of 6-8 x 10(4) at nominal HV. This allows one to use HPDs with very fast low-noise voltage amplifiers and to detect fast pulses (down to the single photoelectron level) with very good amplitude resolution. Of special interest are HPDs of the type R7110U-40 with GaAsP photocathode which provide a quantum efficiency of similar to 40% in maximum at similar to 500 nm. Results on the evaluation of the above-mentioned HPDs and their comparison with HPDs from INTEVAC will be presented. (C) 2000 Elsevier Science B.V. All rights reserved.