We demonstrate that the pedestal components observed in the power spectra of a directly modulated laser diode, which were interpreted as a sign of instability of the periodic regime, are an indication of the coexistence of a chaotic regime with the periodic one. We present the underlying dynamics behind the rise of these pedestals, showing two different situations in which the pedestals appear. In both, a periodic regime coexists with another attractor, a saddle cycle in one case and a chaotic attractor in the other. The random fluctuations included in the laser diode model allow the coexisting attractors to merge in the observed behavior of the laser.
© 1999 Optical Society of America
(140.1540) Lasers and laser optics : Chaos
(140.2020) Lasers and laser optics : Diode lasers
(140.3490) Lasers and laser optics : Lasers, distributed-feedback
(190.3100) Nonlinear optics : Instabilities and chaos
Guillermo Carpintero and Horacio Lamela, "Underlying dynamics of the pedestal components in a modulated laser diode with noise," Opt. Lett. 24, 1711-1713 (1999)