Abstract

We present our recent theoretical and experimental results on pattern formation in lasers. We measured the local intensity and the intensity cross correlation function of patterns emitted by a CO₂ laser with a Fresnel number around 60 and found evidence of weak turbulence [1, 2, 3]. We showed theoretically, that the spatio-temporal dynamics of such a laser can be governed by two fields. One leads to a "turbulent” state principally through phase fluctuations, whereas the other yields a periodic modulation in space and time of the intensity. This can explain why the intensity of the laser is locally chaotic but the time-averaged intensity pattern retains the global symmetry of the system.

© 1996 IEEE