Polarization Dynamics of Current-Modulated Vertical-Cavity Surface-Emitting Lasers

Abstract

Abstract-We study the dynamics of vertical-cavity surface-emitting lasers (VCSELs) with direct current modulation in the framework of a model for index-guided VCSELs that takes into account two orthogonal linear polarizations. We analyze the effect of current modulation near the polarization switching (PS) of type I, from the high to the low frequency polarization, and near the PS of type II, from the low to the high frequency polarization. We find that the oscillations of the total power are as those of a single-mode laser, unaffected by the underlaying polarization coexistence or polarization competition. We also study the small-signal modulation response in the Fourier domain, for modulation dc values near the PS point. Close to type I PS the response of the total power as well as the response of the orthogonal polarizations has the same functional dependency on the modulation frequency, and can be fitted by the response function of a single-mode laser. Close to type II PS, polarization competition is a significant process at low modulation frequencies. The polarization-resolved modulation response displays features at low frequencies that are not present in the response of the total power, which is as that of a single-mode laser. The dynamics becomes increasingly complex as the modulation amplitude grows, and there is multistability of solutions.

Chaos and pulse packages in current-modulated VCSELs

“…While increasing the injection current, a switching from one mode to another is observed. This behaviour, called polarization switching (PS), can be accompanied by a complex dynamics characterized by the coexistence of both PMs with the same or different frequencies [1,2].…”

“…When VCSELs are used for high-bit-speed optical communication systems, current modulation (CM) is required over bias current. The dynamics of VCSELs excited with CM has been a subject of particular interest because of the appearance of many types of interesting behaviour, such as time-periodic pulsing dynamics, chaotic behaviour [3] and train of pulses [1]. With multi-transverse mode VCSELs under CM, chaotic behaviour has been attributed to transverse-mode competition [4,5].…”

“…Recently, investigation of VCSELs subjected to CM has shown a new complex dynamics characterized by a group of irregular pulses (more than 2) appearing in both PMs. For low modulation, these pulses turn into trains of pulses and their amplitude decreases [1].…”

Dynamics of polarization switching in single-mode injection semiconductor lasers

“…Although the sudden switching of the polarization state of the output from semiconductor injection lasers is an effect that has been known for quite a long time [1,2], only recently have the dynamical aspects of this phenomenon been studied in the case of vertical-cavity surface-emitting lasers (VCSEL) [3][4][5][6]. This interest originates in the possible use of VCSEL in optoelectronic systems, while "spontaneous" polarization switching is undesirable in polarization sensitive systems.…”

Chaos synchronization in chaotic current modulated VCSELs by bidirectional coupling

“…Many researchers have proved that in certain conditions, current modulated vertical cavity surface-emitting lasers (VCSELs) are able to exhibit not only periodic and chaotic behaviors (Masoller et al 2007;Valle et al 2007;Mbé et al 2010;Kingni et al 2012). but also pulse packages (Mbé et al 2010;Kingni et al 2012;Tabaka et al 2006).…”