Demonstration of atmospheric lidar measurement in the infrared wavelength domain with a superconducting nanowire single photon detector

Lidar measurement are widely used today for remote sensing and atmosphere monitoring. Indeed, depending on the specific wavelength adopted, it is possible to determine the presence of specific molecules and pollutants in the atmosphere. Several studies claim that the use of Lidar systems with wavelength larger than 1 µm would provide a special tool for aerosols and carbon dioxide observations. Aerosols measurements are typically performed up to the wavelength λ = 1064 nm, while for longer wavelengths they are limited by the detector noise. In this work the results of a preliminary Lidar measurement at λ = 1064 nm by using a Superconducting Nanowire Single Photon Detector (SNSPD) are presented. SNSPDs are characterized by high efficiency in the infrared wavelength domain (IR), low noise and dead time, which can in turn enhance the signal quality in Lidar atmospheric measurements at λ > 1 µm, an interesting range for environmental applications. Preliminary measurements have been performed at the University of Naples Federico II by using a NbTiN SNSPD cooled at a temperature of 4.2 K and the Lidar system MALIA. The experimental results at 1064 nm demonstrate the feasibility of the approach for aerosol measurements in the IR, opening the way to further investigations on the use of these detectors for Lidar atmospheric measurements in the IR. The backscattering coefficient, β, has been also estimated and its value is around 10-6 m-1sr-1