Excelitas’ family of single photon counting modules (SPCMs) are self-contained modules that meet the low light level analytical detection demands of confocal microscopy, fluorescence, luminescence, and TCSPC. Excelitas' SPCMs offer market-leading photon counting performance in parameters like high photon detection efficiency (PDE), low afterpulsing, highest uniformity over an active area, high linear dynamic range, and low dark counts. Excelitas’ entire series of single photon counting modules are designed and built to be fully RoHS-compliant.

Excelitas' SPCMs are the original APD-based photon counting devices on the market. They use a unique avalanche photodiode (APD) that was developed specifically to be operated in so-called “Geiger-mode,” which means operated above breakdown voltage. This enables a single incoming photon to trigger an avalanche of electrons already large enough to be detected and counted as an electronic pulse. The Excelitas SPCM uses a unique silicon avalanche photodiode (SLiK) with a circular active area intended for peak photon detection efficiency. The photodiode is both thermoelectrically-cooled and temperature-controlled, ensuring stabilized performance despite ambient temperature changes.