R2658P

The R2658 and the R2658P are 28 mm (1-1/8 inch) diameter side-on photomultiplier tubes using a newly developed InGaAs semiconductor photocathode.

The InGaAs photocathode is sensitive from UV to near IR radiations (as long as over 1010 nm) longer than wavelength limit of GaAs photocathode, and yet offers low dark current. The dark current is 2 orders lower than the commercial S-1 photocathode. Therefore, they are well suited for low light detection in the near IR region including fluorescence lifetime measurements. Time response, gain, and dimensions are identical with the conventional 28 mm (1-1/8 inch) diameter side-on tubes with a GaAs photocathode.

The R2658P is a photon counting version of the R2658 with low dark counts.