@inproceedings{06e09115581e4b0dbda3bed21dd7271d,
title = "High internal differential efficiency mid-infrared quantum cascade lasers",
abstract = "Implementation of the step-taper active-region (STA) design to 8-9 μm-emitting quantum cascade lasers (QCLs) has resulted in both high T0 and T1 values: 220 K and 665 K, and short lower-level lifetimes: 0.12 ps. In turn, the internal differential efficiency ηid, which is the product of the injection efficiency and the differential laser-transition efficiency, reaches values as high as 86 \% for both 8.4 μm- and 8.8 μm-emitting QCLs. Such ηid values are 30-50\% higher than those obtained from conventional QCLs emitting in the 7-11 μm wavelength range. Achieving both carrier-leakage suppression and miniband-like carrier extraction in mid-infrared (IR) QCLs leads to ηid values close to the fundamental limit of ∼ 90 \%. In turn, the currently employed fundamental wallplug-efficiency limits over the mid-IR wavelength range have to be increased by ∼ 34 \% (e.g., the wallplug-efficiency limit at λ= 4.6 μm increases from 29 \% to 39 \%). Preliminary results from STA-type 4.8-5.0 μm-emitting QCLs include 1.5 W CW operation, and 77 \% internal differential efficiency; that is, 30-50\% higher than the ηid values obtained from conventional 4.0-6.5μm-emitting QCLs.",
keywords = "Carrier-leakage suppression, Internal differential efficiency, Quantum cascade laser, Resonant-tunneling carrier extraction, Temperature sensitivity, Wallplug efficiency",
author = "Dan Botez and Kirch, \{Jeremy D.\} and Chang, \{Chun Chieh\} and Colin Boyle and Honghyuk Kim and Oresick, \{Kevin M.\} and Chris Sigler and Mawst, \{Luke J.\} and Minhyeok Jo and Shin, \{Jae Cheol\} and Doo Gun-Kim and Lindberg, \{Don F.\} and Earles, \{Thomas L.\}",
note = "Publisher Copyright: {\textcopyright} 2017 SPIE.; Novel In-Plane Semiconductor Lasers XVI 2017 ; Conference date: 30-01-2017 Through 02-02-2017",
year = "2017",
doi = "10.1117/12.2249537",
language = "English",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Smowton, \{Peter M.\} and Belyanin, \{Alexey A.\}",
booktitle = "Novel In-Plane Semiconductor Lasers XVI",
}