Stimulating polarization switching dynamics in mid-infrared quantum cascade lasers
Abstract
A unique feature of quantum cascade lasers relies on the ultrafast carrier relaxation lifetime that occurs on a picosecond time scale. Furthermore, the very sharp electronic transitions among the conduction-band states (subbands) lead to specific selection rules, which in theory exclude the TE-polarized light emission. Under cross-polarization reinjection, we stimulate the polarization switching dynamics in such an intersubband device. The mid-infrared modulation signal is phase-shifted between the TM mode and the TE mode, with a typical microsecond time scale different from pure time-delay dynamics. We also prove that both the frequency and the duty cycle of the modulated pattern can be slightly tuned by varying the characteristics of the reinjected light. These results reveal the possibility of favoring the TE polarization in a quantum cascade laser and generating a square-wave modulation with cross-polarization reinjection.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 14, 2021
- Source ID
- 10.1364/josab.425097
Entities
People
- Andreas Herdt
- Frédéric Grillot
- Olivier Spitz
- Wolfgang Elsässer
Organizations
- Agence Nationale de la Recherche
- Direction générale de l'Armement
- Polytechnic Institute of Paris
- Technical University of Darmstadt
- University of New Mexico