Chaos in lasers: practical and metrological implications
Authors: Arecchi F.T., Meucci R.
Autors Affiliation: Istituto Nazionale di Ottica, Largo E. Fermi 6, 50125 Firenze, Italy
Department of Physics, University of Firenze, 50125 Firenze, Italy
Abstract: It is noted that a single-mode laser, ruled by the three Maxwell-Bloch equations for field amplitude, polarization, and population inversion, should be chaotic. Whenever the relaxation rates of the three coupled quantities are wildly different, (that is, depending on the gain medium and cavity damping), lasers may be reduced to one or two degrees of freedom. The authors call classes A and B those lasers that are ruled, respectively, by one or two equations and where chaos can only be induced by addition of an extra variable. They call class C those lasers where all three variables relax at comparable rates and hence chaos can arise spontaneously. Only in the far IR are there examples of class C lasers. The most common ones are class A (e.g., He-Ne, A, dye) or class B (e.g., ruby, Nd, CO2, semiconductor). As one moves from single-mode to many-mode operation, any laser type can be driven chaotic. A single-mode class B laser in the presence of laboratory manipulations (modulation, feedback, injection from another laser) can acquire the third degree of freedom necessary to make it chaotic.
KeyWords: Chaos Theory; Relaxation Processes, Digest of Paper; Maxwell-Bloch Equations; Metrology; Population Inversion, Lasers