Cavity-sensitive amplified spontaneous emission with radiation reabsorption

Area of Science:

• Laser Physics
• Quantum Optics
• Materials Science

Background:

• Amplified spontaneous emission (ASE) is a critical phenomenon in lasers.
• Radiation reabsorption can significantly influence ASE dynamics.
• Understanding these effects is crucial for optimizing laser performance.

Purpose of the Study:

• To experimentally and numerically investigate ASE in an end-pumped ruby laser with radiation reabsorption.
• To analyze the impact of cavity configuration on ASE characteristics.
• To explain observed phenomena like power variations and spectral enhancements.

Main Methods:

• Utilized an end-pumped ruby laser setup.
• Performed experimental measurements of fluorescence time decay.
• Conducted numerical simulations to model ASE behavior.
• Analyzed axial and side emission characteristics.

Main Results:

• Average ASE path length was found to be much larger than the reabsorption length.
• ASE path length showed sharp variations near the semi-concentric cavity configuration.
• Side emission lifetime was independent of the cavity configuration.
• An axial power bump correlated with a side power valley was observed.
• Enhanced fluorescence R-line spectrum was detected and explained.

Conclusions:

• Radiation reabsorption significantly affects ASE in ruby lasers.
• Cavity configuration plays a crucial role in ASE path length and power distribution.
• The study provides insights into optimizing laser design by controlling ASE and reabsorption.