Multimode regimes in quantum cascade lasers: From coherent instabilities to spatial hole burning Academic Article uri icon

abstract

  • A theoretical and experimental study of multimode operation regimes in quantum cascade lasers (QCLs) is presented. It is shown that the fast gain recovery of QCLs promotes two multimode regimes: One is spatial hole burning (SHB) and the other one is related to the Risken-Nummedal-Graham-Haken instability predicted in the 1960s. A model that can account for coherent phenomena, a saturable absorber, and SHB is developed and studied in detail both analytically and numerically. A wide variety of experimental data on multimode regimes is presented. Lasers with a narrow active region and/or with metal coating on the sides tend to develop a splitting in the spectrum, approximately equal to twice the Rabi frequency. It is proposed that this behavior stems from the presence of a saturable absorber, which can result from a Kerr lensing effect in the cavity. Lasers with a wide active region, which have a weaker saturable absorber, do not exhibit a Rabi splitting and their multimode regime is governed by SHB. This experimental phenomenology is well-explained by our theoretical model. The temperature dependence of the multimode regime is also presented. 2008 The American Physical Society.

published proceedings

  • PHYSICAL REVIEW A

author list (cited authors)

  • Gordon, A., Wang, C. Y., Diehl, L., Kaertner, F. X., Belyanin, A., Bour, D., ... Capasso, F.

citation count

  • 169

complete list of authors

  • Gordon, Ariel||Wang, Christine Y||Diehl, L||Kärtner, FX||Belyanin, A||Bour, D||Corzine, S||Höfler, G||Liu, HC||Schneider, H||Maier, T||Troccoli, M||Faist, J||Capasso, Federico

publication date

  • May 2008