Paulo Henrique Dias Ferreira

arXiv2026

Efficiency-Resolved Recovery Dynamics of an Free-Running InGaAs/InP Single Photon Avalanche Detector Operated in Gated Mode

Detection efficiency in gated-mode single-photon avalanche detectors recovers gradually after each gate edge, limiting attainable count rates, yet quantitative recovery models exist only for free-running operation. We extract the gated recovery time constant of a free-running InGaAs/InP detector at 1550 nm by sweeping the gate frequency from 100 kHz to 1 MHz and globally fitting count rates across four dead times, requiring neither a pulsed laser nor a time-to-digital converter. The recovery time decreases linearly with detection efficiency, from 301 to 161 ns between 10 % and 25 %, at 9.3 ns per percentage point. We further resolve a periodic count-rate modulation consistent with bias-dependent capacitive gate feedthrough.

quant-ph↗

arXiv2025

Pulsed Laser as a Continuous Particle Stream

With the recently introduced particle interpretation of the double-slit experiment for light fields [Phys. Rev. Lett. 134, 13360 (2025)], all related interference phenomena can be reinterpreted in terms of light particle states that either couple (bright) or do not couple (dark) with detectors. Here, we apply this approach to multimode pulsed lasers, unifying the description of their generation inside optical cavities and propagation outside them, now relying solely on quantum mechanics, i.e., without invoking wave superposition to explain pulse shaping. Specifically, we demonstrate that multimode interference presents a dominance of particle dark states over the bright ones and mode-locked pulsed lasers consist of a continuous photon beam, with photons forming bright states during pulses and dark states in between. Additionally, we analyze mode-locked pulsed lasers, showing that the theoretical bright-to-dark state ratio matches the experimental pulse-to-interval duration ratio.

quant-ph↗