Measure detector timing performance (jitter) in the TD‑fNIRS setup

Measure and quantify the timing performance (jitter) of the APD- and SiPM-based detector approaches within the Red Pitaya TDC time-of-flight setup to verify suitability for approximately 100 ps temporal resolution required by time-domain fNIRS.

Background

Achieving accurate temporal point spread functions in TD‑fNIRS requires low timing jitter across the laser source, detector, and TDC. While the TDC performance was characterized, the detector timing performance has not yet been measured.

Without these measurements, the system’s effective temporal resolution and the relative merits of APD versus SiPM remain uncertain, directly impacting achievable tomographic resolution.