Figure 1
From: Demonstration of measuring sea fog with an SNSPD-based Lidar system

Schematic diagram of the laser measurement system (OF: Optical filter, AA: Adjustable attenuator). When the laser signals are propagated in the atmosphere, cloud, rain, ice, and other suspended particles cause a scattering of the signals. An optical telescope receives the backscattered light and the SNSPD is used to convert the optical signals into electric pulse signals.