Nonlinear Phenomena in Complex Systems, 2010, Vol.13, No.1, pp.32-37

NONLINEAR PHENOMENA IN COMPLEX SYSTEMS
An Interdisciplinary Journal

2010, Vol.13, No.1, pp.32-37

Stochastic Properties in Bistable Region of Single-Transverse-Mode Vertical-Cavity Surface-Emitting Lasers.
Surasak Chiangga and T. D. Frank

We study the role of the bias current in the polarization dynamics in regions of polarization bistability of a single-transverse-mode vertical-cavity surface-emitting laser diode which exhibits elliptical polarization before switching. We find that the bias current affects the mean intensity of one polarization mode in the polarization switching domain, while it does not affect the other mode. The time series of the polarized intensity fluctuations for different values of the bias current are analyzed in terms of a stochastic Langevin equation. We show how to extract the drift function and the resulting potential of the Langevin equation from the observed data. We find that the potentials obtained from Langevin drift functions are in excellent agreement with the Boltzmann probability distribution of the experimental data. We find that intensity fluctuations are determined by both monostable and bistable potentials. In particular, we observed double-well (bistable) potentials at the low bias current region of the polarization switching domain.
Key words: polarization switching, bistability, data analysis, vertical-cavity surface-emitting lasers (VCSELs)

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