Stimulated Secondary Emission of Single Photon Avalanche Diodes

TL;DR

This study measures secondary photon emission spectra from SiPM devices during charge avalanches, revealing photon yields and temperature independence, which enhances understanding of cross-talk noise in photon detection systems.

Contribution

It provides the first detailed spectra and photon yield measurements of stimulated secondary emission from SiPMs at various voltages and temperatures.

Findings

Photon yields of 40±9 and 61±11 per avalanche for two SiPM types.

No significant temperature dependence observed.

Quantitative data on secondary photon emission aiding noise modeling.

Abstract

Large-area next-generation physics experiments rely on using Silicon Photo-Multiplier (SiPM) devices to detect single photons, which trigger charge avalanches. The noise mechanism of external cross-talk occurs when secondary photons produced during a charge avalanche escape from an SiPM and trigger other devices within a detector system. This work presents measured spectra of the secondary photons emitted from the Hamamatsu VUV4 and Fondazione Bruno Kessler VUV-HD3 SiPMs stimulated by laser light, near operational voltages. The work describes the Microscope for the Injection and Emission of Light (MIEL) setup, which is an experimental apparatus constructed for this purpose. Measurements have been performed at a range of over-voltage values and temperatures from 86~K to 293~K. The number of photons produced per avalanche at the source are calculated from the measured spectra and determined to be 40$\pm$9 and 61$\pm$11 photons produced per avalanche for the VUV4 and VUV-HD3 respectively at 4 volts over-voltage. No significant temperature dependence is observed within the measurement uncertainties. The overall number of photons emitted per avalanche from each SiPM device are also reported.