Fig. 1: Photon detection by click/no-click detectors with sharp energy thresholds.
From: Quantum light detection in high-temperature superconducting nanowires
a Conceptual diagram: a laser pulse with mean photon number μ = 1 may contain higher photon numbers randomly distributed across M detector elements. b Pulse detection probability for single- and multi-element detectors (dashed and dotted curves, Eq. (3)). \(R=\,\text{ceil}\,(\frac{{U}_{0}}{h\nu })\) denotes the threshold energy U0 as an integer of photon energy hν and determines the slope PDP(μ ≪ 1) ∝ μR, δU is the effective width of the threshold. The inset depicts the idealized detection efficiency η = 1; a “click" occurs if the total energy of photons simultaneously impinging on the same element exceeds the threshold energy U0, otherwise “no-click". Regardless of M, the click probability maintains discrete slopes at small μ (see the main text).
