Terahertz ambipolar dual-wavelength quantum cascade laser.
Terahertz frequency quantum cascade lasers (THz QCLs) are compact solid-state sources of terahertz radiation that were first demonstrated in 2002. They have a broad range of potential applications ranging from gas sensing and non-destructive testing, through to security and medical imaging, with many polycrystalline compounds having distinct fingerprint spectra in the terahertz frequency range. In this article, we demonstrate an electrically-switchable dual-wavelength THz QCL which will enable spectroscopic information to be obtained within a THz QCL-based imaging system. The device uses the same active region for both emission wavelengths: in forward bias, the laser emits at 2.3 THz; in reverse bias, it emits at 4 THz. The corresponding threshold current densities are 490 A/cm(2) and 330 A/cm(2), respectively, with maximum operating temperatures of 98K and 120 K.
Lever
L
L
Institute of Microwaves and Photonics, School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom. l.j.m.lever@leeds.ac.uk
Hinchcliffe
N M
NM
Khanna
S P
SP
Dean
P
P
Ikonic
Z
Z
Evans
C A
CA
Davies
A G
AG
Harrison
P
P
Linfield
E H
EH
Kelsall
R W
RW
D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007834:Lasers; D011789:Quantum Theory; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055053:Terahertz Radiation