Transverse Mode Switching and Locking in Vertical-Cavity Surface-Emitting Lasers Subject to Orthogonal Optical injection

Ángel Valle (1) , Ignace Gatare (2, 3) , Krassimir Panajotov (3) , Marc Sciamanna (2)

1 IFCA - Instituto de Fisica de Cantabria
2 LMOPS - Laboratoire Matériaux Optiques, Photonique et Systèmes
3 TONA - Department of Applied Physics and Photonics [Brussels]

In this paper, we report on theoretical and experimental investigation on polarization and transverse mode behavior of vertical-cavity surface-emitting lasers (VCSELs) under orthogonal optical injection as a function of the injection strength and of the detuning between the injection frequency and the free-running frequency of the solitary laser. As the injection strength increases the VCSEL switches to the master laser polarization. We find that the injection power necessary to obtain such polarization switching is minimum at two different values of the frequency detuning: the first one corresponds to the frequency splitting between the two linearly polarized fundamental transverse modes, and the second one appears at a larger positive frequency detuning, close to the frequency difference between the first-order and the fundamental transverse modes of the solitary VCSEL. We show theoretically that both the depth and the frequency corresponding to the second minimum increase when the relative losses between the two transverse modes decrease. Bistability of the polarization switching is obtained for the whole frequency detuning range. Such a bistability is found for the fundamental mode only or for both transverse modes, depending on the value of the detuning. The theoretical and experimental optical spectra are in good agreement showing that the first-order transverse mode appears locked to the external injection.

Mots clés: laser cavity resonators; laser mode locking; laser modes; light polarisation; optical bistability; optical switches; semiconductor lasers; surface emitting lasers

Domaines: Optique [physics.optics]; Optique / photonique

Ángel Valle, Ignace Gatare, Krassimir Panajotov, Marc Sciamanna. Transverse Mode Switching and Locking in Vertical-Cavity Surface-Emitting Lasers Subject to Orthogonal Optical injection. IEEE Journal of Quantum Electronics, 2007, 43 (4), pp.322-333. ⟨10.1109/JQE.2007.893004⟩. ⟨hal-00207538⟩