Photon Detection Efficiency Calculator (SiPM)

Silicon Photomultipliers function by arraying numerous avalanche photodiodes operating in Geiger mode on a single silicon substrate. The fundamental equation governing their performance links responsivity ($R$) to photon detection efficiency ($PDE$), wavelength ($\lambda$), internal gain ($G$), afterpulsing probability ($AP$), and optical crosstalk ($CT$). The primary formula used is:

responsivity = pde * lambda_var * gain * 806554.400077 * (1 + afterpulsing) * (1 + crosstalk)

Here, the constant factor incorporates fundamental physical constants including the elementary charge, the speed of light, and Planck's constant, normalized to convert optical power into electrical current effectively.

Consider an experimental setup utilizing a high-performance SiPM under specific laboratory conditions. Let us assume a Photon Detection Efficiency (PDE) of 0.40 (40%), an operating wavelength ($\lambda$) of 550 nm, and a device gain ($G$) of $1 \times 10^6$. Furthermore, assume an afterpulsing probability of 0.03 (3%) and a crosstalk probability of 0.05 (5%). Plugging these values into our core formula:

responsivity = 0.40 * 550 * 1,000,000 * 806554.400077 * (1 + 0.03) * (1 + 0.05)

Evaluating this expression yields a calculated responsivity that accounts for secondary avalanche triggers, providing an accurate prediction of the macroscopic current generated per watt of incident optical power.

To ensure high accuracy when evaluating your silicon photomultiplier system, always verify your input units—particularly ensuring wavelengths are specified in nanometers and gains are properly scaled. Keep in mind that environmental factors such as ambient temperature can significantly alter afterpulsing and breakdown voltage, so recalibrate your parameters dynamically when operating outside controlled room conditions.