White Paper: Noise In Silicon Photomultipliers And Vacuum Photomultiplier Tubes

The ability to detect single photons represents the ultimate sensitivity in optical detection. To achieive such sensitivity a number of technologies have been developed and re ned to suit particular applications. These include Photomultiplier Tubes (PMTs), linear and Geiger mode Avalanche Photo Diodes (APDs), Charge Coupled Detectors (CCDs), Visible Light Photon Counting (VLPC) detectors and Hybrid Photon Detectors (HPD). The need for ever more sensitive, compact, rugged and inexpensive optical sensors in the visible region of the spectrum continues today and is particularly accute in the fields of the biological sciences, medicine, astronomy and high energy physics. Applications such as fluorescence and luminescence photometry, absorption spectroscopy, scintillator readout, LIDAR and quantum cryptography require extremely sensitive optical sensors often in adverse environments, such as high magnetic fields, and where space is limited.