Intrinsic instabilities in homogeneously broadened lasers
Abstract
Elementary theoretical treatments of homogeneous broadening predict that such lasers can operate in only a single mode, because all of the atoms constituting the gain medium experience identical degrees of saturation. These same arguments apply in the case of a homogeneously broadened absorber. The saturated medium is unstable to the development of self modulation which allows modes symmetrically displaced from the original mode to grow. These modes are locked in a definite relative phase and amplitude. They are natural modes which satisfy a simple eigenvalue equation. This effect occurs in an amplifier as well as in an absorber, and in the case of an amplifier it can lead to higher gain in the wings than near line center. The laser becomes unstable and switches to multimode behavior with a characteristic mode separation.
- Publication:
-
In Opt. Soc. Am. Topical Meeting on Opt. Bistability 2p (SEE N84-24381 14-76
- Pub Date:
- January 1984
- Bibcode:
- 1984osa..meetU....H
- Keywords:
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- Concentration (Composition);
- Gas Lasers;
- Laser Mode Locking;
- Laser Modes;
- Laser Stability;
- Phase Locked Systems;
- Absorbers (Materials);
- Absorption Spectra;
- Amplitudes;
- Laser Pumping;
- Threshold Currents;
- Lasers and Masers