Electronic model for VCSELs: Switching mode, control of threshold current and saturation

An electronic model of VCSELs based on the mathematical rate equations of Danckaert et al. [J. Danckaert, B. Nagler, J. Albert, K.K. Panajotov, I. Veretennicoff, T. Erneux, Opt. Commun. 201 (2002) 129] is built. The polarization switching (PS) phenomenon is generated. The PS phenomenon here is analyzed using two methods. In the first method, the behavior of the polarization modes is investigated in terms of the injection voltage parameter. A threshold voltage value and a switching value are obtained as prescribed by the theoretical model. In the second method, the ratio of the voltages (modes) outputs is plotted in terms of the voltage parameter. It is found that the ratio reaches a maximum at a critical value of the voltage parameter. Controlling the threshold current, it is found that it can be reduced voluntarily by the use of an external voltage supplier (denoted E2). When E2 increases, the threshold current decreases and the maximum reached by the polarization mode increases. When the control voltage is high and below a second critical value, the polarization modes saturate to the same value. But above this critical value, they saturate to opposite values.