High power and single mode quantum cascade lasers

Lateral distributed-feedback gratings for single-mode, high-power terahertz quantum-cascade lasers.

We report on terahertz quantum-cascade lasers (THz QCLs) based on first-order lateral distributed-feedback (lDFB) gratings, which exhibit continuous-wave operation, high output powers (>8 mW), and single-mode emission at 3.3-3.4 THz. A general method is presented to determine the coupling coefficients of lateral gratings in terms of the coupled-mode theory, which demonstrates that large couplin...

“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...

Title Tunable single-mode slot waveguide quantum cascade lasers

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...