Laser LIA ILNACS
Staff: A.N. Baranov (DR), R. Teissier (DR), M. Bahriz (MCf), Y. Rouillard (MCf), A. Vicet (MCf)
PhD students: Q. Gaimard (2012 – 2014)
Current collaborations: LPN (Marcoussis), LAAS (Toulouse), MPQ (Paris), IEF (Paris)
IOFFE (Russie), NANOPLUS (Germany), Univ. ASTON (UK)
Since the mid-80s the group is engaged in the development of mid-infrared antimonide diode lasers fabricated first by liquid phase epitaxy and later by MBE. The GaSb-based quantum well lasers of the last generation are able to operate in the continuous wave regime in the wavelength range of 2 – 3.5 µm. Single frequency emitters suitable for tunable diode laser absorption spectroscopy have been actively developed within the group and in collaboration with industrial companies in the USA and Europe: JPL (USA), Blue Leaf (USA), NANOPLUS (Germany) (Fig.1).
Within the framework of the International Associated Laboratory ILNACS we are developing active whispering gallery mode (WGM) devices for system-on-chip applications operating in the mid-infrared. WGM lasers with a disk or ring resonator are attractive for use in photonic micro systems due to their small dimensions and possibility of their efficient coupling with planar waveguides. They are also promising for the development of compact high-speed optical and electronic oscillators. WGM diode lasers emitting at 2 – 2.5 µm with multisection, coupled and cleaved resonators are being fabricated and studied to realize different functionalities of these devices (Fig.2).
Quantum cascade lasers (QCLs) exploiting intersubband transitions in electron quantum wells is another focus of the group activity. We are developing QCLs based on the InAs/AlSb material system. The high conduction band offset between these materials allowed us to fabricate the first QCLs emitting at wavelengths shorter than 3.5 µm, which was an extremely difficult task for this class of semiconductor lasers. We finally set the new short wavelength border for QCL emission at 2.6 µm. High intersubband gains can be obtained in this system due to the small electron effective mass in InAs. We are working on exploiting this advantage to develop high performance far infrared QCLs. Within the framework of the project DELTA (collaboration with IEF) we have already demonstrated QCLs operating at 17 -21 µm at room temperature. These are the first RT semiconductor lasers emitting above 16 µm (Fig.3). We intend to further expand the area of application of InAs-based QCLs deeper into the far infrared up to the THz domain.