  One of the most common approaches for quenching single-photon avalanche
diodes is to use a passive resistor in series with it. A drawback of this
approach has been the limited recovery speed of the single-photon avalanche
diodes. High resistance is needed to quench the avalanche, leading to slower
recharging of the single-photon avalanche diodes depletion capacitor. We
address this issue by replacing a fixed quenching resistor with a
bias-dependent adaptive resistive switch. Reversible generation of metallic
conduction enables switching between low and high resistance states under
unipolar bias. As an example, using a Pt/Al2O3/Ag resistor with a commercial
silicon single-photon avalanche diodes, we demonstrate avalanche pulse widths
as small as ~30 ns, 10x smaller than a passively quenched approach, thus
significantly improving the single-photon avalanche diodes frequency response.
The experimental results are consistent with a model where the adaptive
resistor dynamically changes its resistance during discharging and recharging
the single-photon avalanche diodes.
