Title :
Incomplete inversion and double-valued fundamental linewidth of infrared HeNe and HeXe lasers
Author :
Kuppens, S.J.M. ; van Eijkelenborg, M.A. ; Schrama, C.A. ; van Exter, M.P. ; Woerdman, J.P.
Author_Institution :
Huygens Lab., Leiden Univ., Netherlands
fDate :
3/1/1996 12:00:00 AM
Abstract :
We have measured the quantum-limited linewidths of small HeNe 3.39 μm and HeXe 3.51 μm lasers. In contrast to the expected Schawlow-Townes behaviour strong deviations from the inverse power dependence are observed, leading to a double-valued relation between the linewidth and the output power. This phenomenon is analyzed in terms of the increase of spontaneous emission, by a factor Nsp, due to incompleteness of the inversion. Our analysis shows that typically Nsp has a value ranging from 1-10. Combining existing models for the pump power dependence of the level populations with measurements of the small signal gain, we are able to explain the observed double-valued linewidth behaviour in a quantitative way
Keywords :
gas lasers; helium; laser theory; laser transitions; neon; population inversion; spectral line breadth; spontaneous emission; xenon; 3.39 mum; 3.51 mum; He-Ne; He-Xe; He-Xe lasers; Schawlow-Townes behaviour; double-valued fundamental linewidth; incomplete inversion; infrared He-Ne lasers; inverse power dependence; level populations; output power; pump power dependence; quantum-limited linewidths; small signal gain; spontaneous emission; Atom lasers; Laser excitation; Laser noise; Laser transitions; Mirrors; Power generation; Power lasers; Power measurement; Pump lasers; Spontaneous emission;
Journal_Title :
Quantum Electronics, IEEE Journal of
