Profiling atmospheric water vapor using a fiber laser lidar system

Area of Science:

• Atmospheric science
• Planetary science
• Laser spectroscopy

Background:

• Accurate water vapor profiling is crucial for understanding Earth's climate and Martian atmospheric dynamics.
• Existing lidar technologies may lack the compactness or efficiency required for versatile atmospheric measurements.

Purpose of the Study:

• To develop and demonstrate a compact, lightweight, and efficient fiber laser lidar system.
• To enable precise measurement of water vapor profiles in the lower atmospheres of Earth and Mars.

Main Methods:

• A Tm:germanate fiber laser, pumped by diode arrays, was engineered for tunable operation near 1.94 micrometers.
• A Q-switched pulsed fiber laser design achieved a 5 Hz pulse repetition rate with ~0.5 mJ pulse energy and a ~20 pm linewidth.
• A lightweight carbon epoxy fiber telescope with a 30 cm Fresnel lens and an HgCdTe Avalanche Photodiode (APD) detector formed the receiver.

Main Results:

• The developed fiber laser lidar system is compact, lightweight, and efficient.
• The system is tunable to specific water vapor absorption lines near 1.94 micrometers.
• Preliminary atmospheric measurements were successfully conducted using the system.

Conclusions:

• The novel fiber laser lidar system presents a viable tool for water vapor profiling in planetary atmospheres.
• The system's design offers advantages in terms of size, weight, and efficiency for remote sensing applications.
• Further atmospheric measurements will validate the system's capabilities for both Earth and Mars exploration.