Abstract

Studies of the power spectra of the intensity fluctuations of a unidirectional single-mode inhomogeneously broadened Xe-He ring laser have suggested that sequences of period doubling bifurcations occurred before transitions to chaotic behavior. Recent experimental measurements of the optical electric field spectrum (by heterodyning the signal with a single stable reference frequency) indicate that the system may often be undergoing a symmetry breaking bifurcation instead. Details of the intensity time series, intensity power spectra, and heterodyne spectra are presented to show the range of parameters over which such phenomena occur. We have also tested these conclusions using our recently developed theoretical model and we find that similar ambiguities appear if only the intensity or modulus of the field is viewed in time or evaluated via the Fourier transforms. A numerical procedure that is equivalent to the optical heterodyning resolves the ambiguity and confirms that symmetry breaking processes should be common to systems such as ours.

© 1985 Optical Society of America