Differential absorption ozone Lidar with 4H-SiC single-photon detectors

TL;DR

This paper demonstrates a UV differential absorption Lidar system for ozone monitoring using novel 4H-SiC single-photon detectors, achieving high performance and accurate ozone measurements comparable to commercial systems.

Contribution

The work introduces a 4H-SiC single-photon avalanche diode design and applies it to ozone DIAL, offering an effective alternative for UV Lidar applications.

Findings

SPD exhibits 16.6% detection efficiency at 266 nm

Dark count rate of 138 kcps and maximum count rate of 13 Mcps

Ozone concentration measurements agree with commercial DIAL results

Abstract

Differential absorption Lidar (DIAL) in the ultraviolet (UV) region is an effective approach for monitoring tropospheric ozone. 4H-SiC single-photon detectors (SPDs) are emergent devices for UV single-photon detection. Here, we demonstrate a 4H-SiC SPD-based ozone DIAL. We design and fabricate the 4H-SiC single-photon avalanche diode with a beveled mesa structure and optimized layer thickness. An active quenching circuit with a quenching time of 1.03 ns is developed to significantly mitigate the afterpulsing effect while enhancing the maximum count rate. After characterization, the SPD exhibits excellent performance with a photon detection efficiency of 16.6% at 266 nm, a dark count rate of 138 kcps, a maximum count rate of 13 Mcps, and an afterpulse probability of 2.7% at room temperature. Then, we apply two 4H-SiC SPDs in an ozone DIAL. The measured ozone concentrations at altitudes of 1-3.5 km agree well with the results of a commercial ozone DIAL. Our work provides an alternative solution for general UV Lidar applications.