Transverse-mode dynamics in vertical-cavity surface-emitting lasers with optical feedback

Abstract

We study the transverse-mode dynamics of vertical-cavity surface-emitting lasers with weak optical feedback. We use a model that takes into account the spatial dependence of the transverse modes and of two carrier density profiles, associated with confined carriers in the quantum well region of the laser and unconfined carriers in the barrier region. Optical feedback is included as in the Lang-Kobayashi model. We find that for adequate parameter values antiphase dynamics occurs. As the injection current varies, the antiphase dynamics is destroyed through a sequence of periodic mixed states leading to in-phase dynamics. In these mixed states there are time intervals in which the modes are in phase, followed by time intervals in which they are in antiphase. We study the origin of the antiphase dynamics, assessing the role of the different spatial profiles. We show that the competition between the different profiles leads to the observed antiphase behavior.

Transverse-mode dynamics in directly modulated vertical-cavity surface-emitting lasers with optical feedback

“…For these parameters, the threshold current is 1.5 mA. If not otherwise stated, the external cavity parameters are the same as in [18], which correspond to weak optical feedback:…”

“…We numerically solve the model equations with typical VCSEL parameters [18]: m, m (three quantum wells of thickness 0.08 m each), m, index step , , with m/ns and m , m , ps, ps, ns, and m ns. All modes have the same confinement factor and losses 2.2 ps.…”

“…It was recently shown numerically that weak optical feedback from a distant reflector induces distinct transverse-mode dynamical regimes [18]. Close to threshold the VCSEL dynamics is single-mode and optical feedback induces periodic oscillations of the laser output.…”

“…In this paper, we study numerically the effect of current modulation in these dynamical regimes. Our simulations are based on the model of [18], which is an extension of the model originally proposed by Valle et al [19], [20]. The model includes spatial profiles for both the 0018-9197/04$20.00 © 2004 IEEE transverse modes and the carrier density.…”

Transverse dynamics in cavity nonlinear optics (2000–2003)

“…have been proposed. Topics covered include spatio-temporal modelling with polarization dynamics [200], modal expansion versus spatio-temporal description [201], effect of carrier transport on transverse mode selection [202], multimode antiphase dynamics with optical feedback [203], analytic solutions [204] of a comprehensive circuit-model [205], and spatio-spectral interaction mechanisms of carriers and photons are observed and explained in [206]. The spatial mode structure of an MQW device has been revisited in [207,208].…”