1.5 μm polarization coherent lidar incorporating time-division multiplexing

Area of Science:

• Atmospheric physics and remote sensing
• Optical engineering
• Meteorology

Background:

• Traditional coherent Doppler lidars (CDLs) often suffer from systematic errors due to detector non-uniformity.
• The perpendicular component of backscattering is typically underutilized in conventional lidar systems.
• Accurate measurement of atmospheric depolarization ratio (ADR) and wind velocity is crucial for meteorological studies.

Purpose of the Study:

• To develop and demonstrate a single versatile coherent Doppler lidar (CDL) capable of simultaneous atmospheric depolarization ratio (ADR) and wind velocity measurements.
• To improve the carrier-to-noise ratio (CNR) in wind detection by utilizing the perpendicular backscattering component.
• To eliminate systematic errors associated with multiple detectors in traditional lidar systems.

Main Methods:

• Utilizing a single balanced detector with time-division multiplexing to acquire parallel and perpendicular backscattering components.
• Implementing a versatile CDL that can switch between polarization-sensitive and traditional modes.
• Employing a 300 ns laser pulse with 100 μJ energy for wind detection.

Main Results:

• Achieved a detection range of 6 km with 0.5 m/s precision in traditional mode.
• Demonstrated the ability to retrieve ADR using the perpendicular backscattering component.
• Showcased improved CNR for wind detection by incorporating the perpendicular component.
• Successfully conducted continuous 26-hour wind detection in the atmospheric boundary layer, proving system robustness.

Conclusions:

• The developed versatile CDL offers a robust and stable platform for simultaneous ADR and wind velocity measurements.
• The system effectively mitigates systematic errors and enhances wind detection performance.
• This technology provides valuable data for understanding atmospheric dynamics and wind structures.