Detector SNR & Comparison Calculator

Calculate signal-to-noise ratio, NEP, and minimum detectable power for photodiodes, APDs, and PMTs. Compare two detector configurations side by side.

Detector Parameters
Signal
Responsivity
0.4084A/W
Signal current
408.4nA
Noise
Shot noise
36.173pA
Dark noise
1.790pA
Johnson noise
127.7pA
Total noise
132.7pA
Dominant source
Johnson noise
Performance
SNR
3077.7
SNR
69.764dB
NEP
3.249pW/√Hz
Min detectable power
324.9pW
Abridged Optics — v1.0Uses exact physical constants (h, c, e, k_B). APD excess noise uses the McIntyre model. PMT excess noise uses F ≈ 1 + 1/δ where δ = M^(1/n).

All information, equations, and calculations have been compiled and verified to the best of our ability. For mission-critical applications, we recommend independent verification of all values. If you find an error, please let us know.