By separating voltage generation from amplification, this optical detection circuit speeds light signal output and limits temperature drift.
Using GaN HEMTs, this transimpedance amplifier withstands radiation in proton therapy gamma detection while reducing noise and pulse-shaping needs.
External collector placement and biasing amplify germanium photodetector current to improve signal-to-noise ratio and detection efficiency.
Current-threshold feedback keeps SPAD bias in the photon-detection range while suppressing dark current and removing reference light paths.