Photon Detection Efficiency Calculator (SiPM)

Written by Great Medico

Updated September 25, 2026 •2 min read

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Electrical results can look precise while a unit, operating mode, or component assumption quietly changes the answer. Photon Detection Efficiency Calculator (SiPM) keeps the calculation tied to the quantities on this page, so you can trace the displayed photon detection efficiency back to the values you entered rather than treating it as a black-box number.

What this calculator does

The Photon Detection Efficiency Calculator (SiPM) turns Afterpulsing probability (PAP), Crosstalk probability (PXT), Wavelength (λ), Responsivity (R) into the page’s Photon detection efficiency using the circuit or component relationship below. Where the page shows supporting quantities, they come from the same idealized model so you can cross-check the headline rather than reading one isolated number.

How to use it

Start with the fields that actually drive this result: Afterpulsing probability (PAP), Crosstalk probability (PXT), Wavelength (λ), Responsivity (R). Keep units consistent with the menus beside the fields and avoid mixing values measured under different conditions. After calculating, change one input at a time if you are comparing scenarios; that makes cause-and-effect much easier to see.

How the calculation works

The current SiPM estimate starts from responsivity and photon energy, using PDE ≈ R·h·c/(q·λ), then adjusts for the entered afterpulsing and crosstalk probabilities. The result is reported as a percentage.

Example

Using the page’s default example (Afterpulsing probability (PAP) = 0.05 %; Crosstalk probability (PXT) = 0.05 %; Wavelength (λ) = 450 nm; Responsivity (R) = 0.3 A/W), the calculator reports Photon detection efficiency of 82.573538 %. Change one driving input at a time and confirm the result moves in the direction predicted by the equation; that is a quick way to catch a unit or mode mistake.

How to interpret the result

Interpret the Photon detection efficiency as an idealized circuit/component quantity for the exact mode and units entered. Use it to compare designs or check hand calculations, but keep component tolerances, ratings, frequency dependence, and real operating conditions in view before turning the number into a hardware decision.

Limitations and notes

The gain field is displayed but does not change the present PDE result. Real SiPM PDE also varies with overvoltage, microcell fill factor, wavelength-dependent quantum efficiency, temperature, and manufacturer-specific crosstalk/afterpulsing definitions.