Progress in self-quenching InP-based single photon detectors

Abstract

The operation of InP-based single photon avalanche diodes (SPADs) in Geiger mode provides great utility for the detection of single photons at near-infrared wavelengths between 1.0 and 1.6 μm. However, SPADs have performance limitations with respect to photon counting rate and the absence of photon number resolution that, at the most fundamental level, can be traced back to the positive feedback inherent in the impact ionization-driven avalanche process. In this paper, we describe the inclusion of negative feedback with best-in-class InP-based single photon avalanche diode (SPAD) structures to form negative feedback avalanche diodes (NFADs) in which many of the present limitations of SPAD operation can be overcome. The use of thin film resistors as monolithic passive negative feedback elements ensures rapid self-quenching with very low parasitic effects. We demonstrate a qualitative difference in the performance of NFADs in the two regimes of small and large negative feedback. With small feedback, we have studied the behavior of the persistent current prior to quenching, for which we have found oscillatory behavior as well as an exponentially distributed duration. For large feedback, we find rapid quenching, accompanied by evidence for a partial discharge of the detector capacitance, leading to charge flows as low as ~3 ×10⁵ carriers associated with each avalanche event.