ENG/ECCS-EPSRC Advanced Interband Cascade Lasers with Innovative Quantum Well Active Regions Grown on Si Substrates

Semiconductor infrared lasers are needed for many applications such as detection of pipe leaks and explosives, environmental and chemical-warfare monitoring, food safety, medical diagnostics, and industrial process control. This project combines novel heterostructures and customized semiconductor materials to demonstrate and develop the much-needed semiconductor lasers. The objectives of the project also include advancement in the understanding and knowledge of how efficient infrared light sources can be made on low-cost Si substrates. The project offers graduate and undergraduate students unique opportunities to pursue education, training and research in multidisciplinary topics (materials science, quantum engineering, photonics, and device fabrication). This project also enhances Oklahoma’s infrastructure for science and technology development and increases the opportunities of students. Many applications require efficient and low-cost mid-infrared semiconductor lasers that can operate continuously with low power consumption at room temperature. By applying an innovative quantum well (QW) active region containing strained InAsP layers to interband cascade lasers (ICLs) in a wide mid-IR spectrum (3-10 μm), their device performance can be significantly improved. Furthermore, advanced waveguide configuration with hybrid cladding layers (with both highly doped semiconductor plasmon layer and superlattice) will be employed and ICLs will be grown on Si substrates, which have much reduced cost and notably higher thermal conductivity compared to GaSb or InAs substrates. As such, ICLs will have improved optical confinement and enhanced thermal dissipation, resulting in further reduced power consumption and higher output power, as well as lowered cost. These ICLs will significantly benefit many useful applications, especially where high power is required or mid-IR systems must be operated with batteries and energy cost/availability is a concern, including space applications with strict constraints on size and electric power. The availability of high-performance ICLs will greatly enhance the capabilities of mid-IR laser instruments and their applications in many areas. This project not only advances the understanding and knowledge of optical science, but it also generates new knowledge in the design of quantum-engineered structures and broadens their applications. This collaborative US-UK project is supported by the US National Science Foundation (NSF) and the Engineering and Physical Sciences Research Council (EPSRC) of United Kingdom Research and Innovation (UKRI), where NSF funds the US investigator and EPSRC funds the partners in the UK. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.