Intracavity absorption spectroscopy with a Nd(3+)-doped fiber laser

Area of Science:

• Laser Physics
• Spectroscopy
• Optical Engineering

Background:

• Broadband fiber lasers are crucial for spectroscopic applications.
• Intracavity absorption presents challenges and opportunities in laser design.
• Atmospheric absorption measurements require high-resolution techniques.

Purpose of the Study:

• To investigate the sensitivity of a broadband neodymium-doped fiber laser to intracavity absorption.
• To record the atmospheric absorption spectrum using this laser system.
• To enhance the equivalent absorber path length for improved measurement accuracy.

Main Methods:

• Operation of a broadband neodymium-doped fiber laser in an external cavity.
• Pumping the laser with an argon-ion laser and later a diode laser.
• Utilizing an intracavity prism for stepwise tuning of the laser emission band.
• Measuring the emission spectrum and its sensitivity to absorption.

Main Results:

• The fiber laser system exhibited high sensitivity to intracavity absorption.
• An equivalent absorber path length of 15 km was achieved with Ar(+)-ion laser pumping.
• A loss-reduced setup with diode laser pumping extended the path length to 150 km.
• The atmospheric absorption spectrum from 1.065 to 1.145 micrometers was successfully recorded.

Conclusions:

• The developed fiber laser system is highly effective for high-resolution atmospheric absorption spectroscopy.
• Increased equivalent absorber path length significantly improves measurement sensitivity.
• Diode laser pumping offers a more efficient and extended path length capability.