Spatio-temporal dynamics in vertical cavity surface emitting lasers excited by fast electrical pulses

We have measured the time average spatial intensity distribution and the sp atio-temporal evolution of the spectrally resolved radiation emitted from b road-area vertical cavity surface emitting lasers (VCSEL) when pumped by a fast current pulse. We show that an intrinsic symmetry break exists due to geometrical asymmetry of the device structure and that the frequency separa tion between different modes allows the evaluation of the asymmetry factor. The space-time behavior shows the appearance of higher-order modes coexist ing or alternating in time. The dynamical behavior shows a chirping in freq uency. (C) 1998 Elsevier Science B.V. All rights reserved.