Micro-pulse polarization lidar at 15  μm using a single superconducting nanowire single-photon detector

Abstract

An all-fiber, eye-safe and micro-pulse polarization lidar is demonstrated with a polarization-maintaining structure, incorporating a single superconducting nanowire single-photon detector (SNSPD) at 1.5 μm. The time-division multiplexing technique is used to achieve a calibration-free optical layout. A single piece of detector is used to detect the backscatter signals at two orthogonal states in an alternative sequence. Thus, regular calibration of the two detectors in traditional polarization lidars is avoided. The signal-to-noise ratio of the lidar is guaranteed by using an SNSPD, providing high detection efficiency and low dark count noise. The linear depolarization ratio (LDR) of the urban aerosol is observed horizontally over 48 h in Hefei [N31°50'37'', E117°15'54''], when a heavy air pollution is spreading from the north to the central east of China. Phenomena of LDR bursts are detected at a location where a building is under construction. The lidar results show good agreement with the data detected from a sun photometer, a 532 nm visibility lidar, and the weather forecast information.

Relationship Analysis of PM<sub>2.5</sub> and BLH using Aerosol and Turbulence Detection Lidar

“…The reasons for the differences in the relationships between BLH and PM2.5 under different pollutant and weather conditions need further studies. This required more data based on different instruments, such as horizontal wind field (Shangguan et al, 2017), temperature profiles (Mattis et al, 2002), and depolarization ratio of aerosol (Qiu et al, 2017) in ABL. The application of such an integrated lidar in this research will contribute to our understanding of ABL and aerosol-cloudprecipitation interactions.…”

Relationship analysis of PM<sub>2.5</sub> and boundary layer height using an aerosol and turbulence detection lidar

“…The reasons for the differences in the relationships between BLH and PM 2.5 may result from both cloud effect and pollutant sources and not just from the precipitation. This required more data based on different instruments, such as horizontal wind field (Shangguan et al, 2017), temperature profiles (Mattis et al, 2002), and the depolarisation ratio of aerosol (Qiu et al, 2017) and pollutant components in the ABL. To probe the mechanism of the BLH-PM 2.5 relations under different conditions, such as before and after the precipitation, not only these observations but also model simulations are needed in further studies.…”

“…In recent decades, lidar are widely used in the lower atmosphere via Mie scattering, Raman scattering and differential absorption (Campbell et al, 2002;Godin et al, 1989;Murray and van der Laan, 1978;Reitebuch, 2012;Renaut et al, 1980;Xia et al, 2007). Aerosol, trace gas concentration, atmospheric density, temperature and wind can be detected by these lidar.…”

Development of Multifunction Micro-Pulse Lidar at 1.5 Micrometer

“…The polarization lidar has shown the capability of identifying different types of aerosols and clouds by analyzing the linear depolarization ratio (LDR). Taking advantage of the lowest attenuation (<1 dB/km) in the fiber and the maturity of optical devices at optical communication band, an allfiber eye-safe polarization lidar incorporating a time-division multiplexing (TDM) technique is developed [7]. Only a single piece of the detector is used to detect the backscatter signals at two orthogonal states in an alternative sequence.…”