High-frequency modulation of argon-ion laser radiation due to stable two-mode oscillation as a mode competition effect
Abstract
Mode competition and mode coexistence effects in the argon ion laser were examined, along with the influence of the excitation parameters on broadening of the energy transition levels. An argon ion laser with a mode spacing of 125 MHz, a discharge current of 10-30 A, a threshold of 18 A, and an emission of 800 mW at 514.5 nm was employed. An analysis is presented for a situation in which the homogeneous line width of the active atoms is comparable to the mode spacing, and the linewidth therefore depends on the excitation level. Lamb's (1964) equations for slowly varying field amplitudes are used to study dual and three mode operation, and it was found that stable dual mode operation is possible with a given modulation frequency. A numerical treatment revealed that a hysteresis effect which was observed indicated that excitation beyond the stable dual-mode regime leads to a jump into a stable three-mode regime with one of the modes being suppressed. The presence of the dual mode regime is due to mode competition because of a strong homogeneous line broadening concurrently with a much larger Doppler broadening.
- Publication:
-
Lasers 1980; Proceedings of the International Conference
- Pub Date:
- 1981
- Bibcode:
- 1981lase.conf..783B
- Keywords:
-
- Argon Lasers;
- Frequency Modulation;
- Laser Modes;
- Laser Stability;
- Light Modulation;
- Doppler Effect;
- Fabry-Perot Interferometers;
- Laser Cavities;
- Optical Resonance;
- Spectral Line Width;
- Lasers and Masers