Optical quality of pulsed electron-beam sustained lasers

Area of Science:

• Optics and Photonics
• Plasma Physics
• Laser Engineering

Background:

• Optical quality in pulsed atmospheric lasers is crucial for performance.
• Density disturbances within the optical cavity can degrade laser performance.
• Understanding the origins of these disturbances is key to improving laser design.

Purpose of the Study:

• To investigate the optical quality of pulsed atmospheric carbon dioxide (CO2) electric lasers.
• To identify the sources and mechanisms of density disturbances in the optical cavity.
• To provide design guidelines for optimizing laser pulse durations.

Main Methods:

• Analysis of edge wave propagation from anode and cathode.
• Evaluation of volumetric heating effects from electric discharge.
• Characterization of density disturbances and their origins.

Main Results:

• Density disturbances are primarily caused by edge waves originating at the anode and cathode.
• Volumetric heating effects from nonuniform electric discharge are negligible.
• The cathode disturbance stems from spatial heating and cathode fall discontinuities.
• The anode disturbance is linked to gas expansion being prevented by a solid surface.

Conclusions:

• Pulsed atmospheric CO2 electric lasers suffer optical degradation due to anode and cathode edge waves.
• Laser pulse durations must be significantly shorter than the acoustic transit time across the cavity.
• Effective laser design necessitates minimizing the impact of these density wave phenomena.