Quantum-cascade lasers based on strain-compensated As operating at room temperature in the first atmospheric window spectral range

• Applicant: Professor Dr. William Ted Masselink
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
• Term: from 2005 to 2008
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5440634

Applications such as high-resolution molecular spectroscopy, trace-gas detection, pollution monitoring, and certain medical diagnoses require milliwatt-level sources of stable single-frequency radiation in the 3-5µ spectral region /1/. The proposed project focusses on investigating and developing high-performance (In,Al)As+A1As/(In,Ga)As quantum cascade lasers (QCLS) on InP that will meet these requirements. The active region design is based on novel two-component barrier regions within straincompensated (In,Al)As/(In,Ga)As structures prepared using gas-source molecular-beam epitaxy on InP substrates. The proposed work includes structure design, growth, processing, and the characterization of both materials and finished lasers. The anticipated results from the proposed research are both in the technology of the lasers including optimized designs and processing approaches as well as in the physics of their operation. Design and processing goals include the extension of our two-component-barrier design to include Sb and improved heat sinking. The fundamental investigations include laser measurements in magnetic fields up to 60 T (in collaboration with Prof. Jean Leotin, Laboratoire National des Champs Magnetiques Pulses, Toulouse, France) to investigate the relevant intra- and inter-valley carrier scattering mechanisms which contribute to the limiting factors of the short wavelength laser action in the material system.

• DFG Programme: Research Grants