Generalized high-spectral-resolution lidar technique with a multimode laser for aerosol remote sensing

Area of Science:

• Atmospheric Science
• Optical Remote Sensing
• Laser Spectroscopy

Background:

• High-spectral-resolution lidar (HSRL) is crucial for atmospheric aerosol remote sensing.
• Current HSRL systems often rely on single-mode lasers, which are complex and require strict environmental stability.
• This limits the robustness and applicability of traditional HSRL instruments.

Purpose of the Study:

• To introduce a novel generalized HSRL technique (MML-gHSRL) that utilizes a multimode laser.
• To demonstrate the feasibility of spectral discrimination using a multimode laser for aerosol and molecular scattering.
• To enhance the robustness and practicality of HSRL systems for remote sensing.

Main Methods:

• Developed the multimode laser generalized HSRL (MML-gHSRL) concept.
• Utilized the periodic characteristics of interferometric spectral discrimination filters (ISDFs).
• Matched the ISDF's free spectral range with the multimode laser's mode interval for spectral discrimination.
• Analyzed and compared Fabry-Perot interferometers (FPI) and field-widened Michelson interferometers (FWMI) as ISDFs.

Main Results:

• Successfully demonstrated spectral discrimination of lidar returns from each longitudinal mode of a multimode laser.
• Quantitative analysis showed comparable performance between FPI and FWMI in the MML-gHSRL system.
• The MML-gHSRL technique effectively overcomes the limitations of single-mode lasers.

Conclusions:

• The MML-gHSRL represents a significant advancement over current HSRL techniques.
• This method offers a more robust and potentially simpler approach to HSRL instrumentation.
• It holds promise for future developments in airborne and satellite-borne aerosol remote sensing.