We present a software based control system for Geiger-mode avalanche photodiodes (GM-APDs) that enables constant photon detection efficiency irrespective of the diode's junction temperature. Furthermore, we demonstrate that this control system enables passively quenched GM-APDs to double the rate of photon detection events before saturation compared to the standard control method that fixes the junction temperature and applied bias voltage. We present data demonstrating the robustness of the GM-APD control system when tested in near-space conditions using a correlated photon pair source carried by a weather balloon to an altitude of 35.5 km.
We present a model for quantum Mie scattering in one dimension, and show that quantum states of light, such as
Fock states, exhibit the same transmission functions as coherent states for an ordinary intensity measurement. If
a number-resolving measurement is carried out instead, we observe narrower transmission functions than for the
classical case. We discuss applications of this effect for high-precision length measurements in interferometry.