We demonstrate novel laser-induced relaxation oscillations in superconducting nanowire single photon detectors (SNSPDs). These oscillations appear when a voltage biased NbTiN nanobridge detector is illuminated with intense pulsed laser light at a repetition rate of ∼19MHz. They differ from the well-known relaxation oscillations by a step-wise increase in frequency and phase locking of the oscillations to the laser pulses. We create a model that incorporates electrical feedback and excludes thermal effects to simulate and explain the origin of the observed laser-induced relaxation oscillations. Qualitative agreement to the experiment is achieved using realistic values for the parameters in the model.
@article{arxiv.2411.09494,
title = {Laser-Induced Relaxation Oscillations in Superconducting Nanobridge Single Photon Detectors},
author = {F. B. Baalbergen and I. E. Zadeh and M. J. A. de Dood},
journal= {arXiv preprint arXiv:2411.09494},
year = {2025}
}