CHAOTIC DYNAMICS OF MODE COMPETITION IN A VERTICAL-CAVITY SURFACE-EMITTING LASER-DIODE UNDER DC EXCITATION

We discuss the dynamics of transverse mode competition in an etched ai r-post vertical-cavity laser diode under dc excitation using an annula r ring contact as a spatial filter. Distinct regions of operation are found for various ranges of fixed bias currents. At 1.5 times threshol d, the device enters a region which exhibits chaotic fluctuations betw een the fundamental and a higher order lasing mode. The dynamics of th ese fluctuations are studied using the method of delays, and a calcula tion of the power spectrum and the correlation dimension are reported. It is found that the dynamics of the choatic fluctuations have a corr elation dimension of approximately 2.8. The results are indicative of a low-dimensional strange attractor underlying the modal competition n oise.