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 ∅ 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 6−8×104 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 ∼40% in maximum at ∼500 nm. Results on the evaluation of the above-mentioned HPDs and their comparison with HPDs from INTEVAC will be presented.