High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings

High Power Thermoelectrically Cooled and Uncooled Quantum Cascade Lasers With Optimized Reflectivity Facet Coatings

Stable Single-Mode Operation of Distributed Feedback Quantum Cascade Laser by Optimized Reflectivity Facet Coatings

In this work, quantum cascade lasers (QCLs) based on strain compensation combined with two-phonon resonance design are presented. Distributed feedback (DFB) laser emitting at ~ 4.76 μm was fabricated through a standard buried first-order grating and buried heterostructure (BH) processing. Stable single-mode emission is achieved under all injection currents and temperature conditions without any...

“High-temperature and high-power THz quantum cascade lasers”

The highest temperature performance in terahertz QCLs has been demonstrated by using active regions based on the resonant-phonon depopulation scheme along with metalmetal waveguides to provide low-loss confinement, which have been used to demonstrate maximum temperatures of 164 K in pulsed mode and 117 K in cw mode. It is expected that there are two primary mechanisms which reduce the populatio...

Temperature Effect on THz Quantum Cascade Lasers

A simple semi-phenomenological model, which accurately predicts the dependence of thresholdcurrent for temperature of Resonant-phonon three well quantum cascade laser based on verticaltransitions is offered. We found that, the longitude optical phonon scattering of thermally excitedelectrons is the most important limiting factor for thermal performance of high frequency THz QCLs.In low frequenc...

High power quantum cascade ring lasers and possible applications

Yanbo Bai received his M.S. degree in Physics and Ph.D. degree in Electrical Engineering from Northwestern University in 2005 and 2011. He is currently a research assistant professor at Northwestern. Since 2005, he has been with the Center for Quantum Devices. His research holds the current performance records of mid-IR quantum cascade lasers (QCLs) in terms of the output power and wall plug ef...