Modeling and Optimization of Longwave Infrared Quantum Cascade Lasers
Abstract
The longwave infrared (LWIR) range (8-10 microns) within the second low-absorption atmospheric window is very important for free-space applications, such as long-range communication, remote sensing of chemical and biological species, and target search and imaging. These applications require portable sources of watt-level coherent optical power that operate reliably for many hours in continuous-wave (CW) mode at room temperature. Quantum cascade lasers (QCLs) are high-power monolithic coherent light sources in the midinfrared. They are electrically driven, unipolar semiconductor devices that achieve population inversion based on quantum confinement and tunneling. Among the LWIR devices, the challenge is to achieve reliable CW room-temperature operation with high wallplug efficiency (WPE), watt-level high optical power, and high brightness. This mode of operation is challenging to model because electrons, lattice, and light are strongly coupled to one another and the problem bridges scales from a single stage to device level. The objective of this project is to enable the long-term reliable, high-optical-power (? 1 W CW), high-WPE, and high-brightness LWIR QCLs (8-10 microns). In order to do that, the PI will work with experimental collaborators to develop and validate a comprehensive simulation tool for predictive theoretical modeling and design of LWIR QCLs under CW, high-power operation. The simulation tool will be multiscale (bridging from a single stage to device level) and multiphysics (coupling electrons, lattice motion, and light). The simulation will rigorously incorporate the relevant loss mechanisms (such as intersubband absorption), account for the effects of all microscopic scattering mechanism on device performance (optical phonons, interface roughness, and alloy scattering), as well as analyze the role of strain on electronic, optical, and thermal parameters of the QCL. The PI will work on the promising (STA-RE) device.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 11, 2018
- Source ID
- FA95501810340
Entities
People
- I. Knežević
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Wisconsin System