Mode splitting and the coherent instability in high-gain lasers
Abstract
A high-gain continuous-wave laser may exhibit an output instability in the form of a periodic pulse train or chaotic signal. It is shown that the mode-splitting interpretation of the instability yields a new understanding of the complex behavior reported in xenon, helium-xenon, and helium-neon lasers. The fundamental frequencies of the instability and the possibility of chaotic output are shown to be consistent with unequally spaced resonant modes that arise close to the laser threshold. With saturation, nonresonant harmonics of the fundamental frequencies appear in the laser output. These harmonics have fixed phases relative to the resonant modes and lead to the complex asymmetries of the pulse shapes. Interaction between the resonant and nonresonant modes can trigger period doubling in the pulse train.
- Publication:
-
Journal of the Optical Society of America B Optical Physics
- Pub Date:
- January 1985
- DOI:
- 10.1364/JOSAB.2.000120
- Bibcode:
- 1985JOSAB...2..120M
- Keywords:
-
- Continuous Wave Lasers;
- Gas Lasers;
- High Gain;
- Laser Modes;
- Laser Stability;
- Multimode Resonators;
- Chaos;
- Laser Cavities;
- Laser Outputs;
- Period Doubling;
- Polarization Characteristics;
- Pulsed Radiation;
- Lasers and Masers