5.6 μm quantum cascade lasers based on a two-material active region composition with a room temperature wall-plug efficiency exceeding 28%

Abstract

5.6 μm quantum cascade lasers based on the Al0.78In0.22As/In0.69Ga0.31As active region composition with the measured pulsed room temperature wall plug efficiency of 28.3% are reported. Injection efficiency for the upper laser level of 75% was measured for the design by testing devices with variable cavity lengths. A threshold current density of 1.7 kA/cm2 and a slope efficiency of 4.9 W/A were measured for uncoated 3.15 mm × 9 μm lasers. Threshold current density and slope efficiency dependence on temperature in the range from 288 K to 348 K for the structure can be described by characteristic temperatures T0 ∼ 140 K and T1 ∼ 710 K, respectively.

Anisotropic wurtzite resonance tunneling structures: stationary spectrum of electron and oscillator strengths of quantum transitions

“…where θ(z) is the Heaviside step function, (6) , m 1 = m (2) and m 2 = m (4) are effective electron masses in the potential barriers and wells of RTS, respectively.…”

“…In recent years, on the basis of binary and triple compounds of nitrides InN, GaN, AlN, quantum cascade lasers (QCL) [1,2] and detectors (QCD) [3][4][5] operating in the infrared range of electromagnetic waves were created. Compared to the QCL [6,7] and the QCD [8,9], which are based on binary and triple arsenide semiconductor GaAs, InAs, AlAs, etc., the mentioned nanodevices have a number of functional advantages. In particular, the temperature stability of nitrides allows nanodevices to operate in a range from cryogenic to room temperature.…”

Spectral purity and tunability of terahertz quantum cascade laser sources based on intracavity difference-frequency generation

“…Two decades after their invention ( 1 ), quantum cascade lasers (QCLs) have reached impressive performance levels in the mid-infrared (mid-IR; λ ≈ 2.5 to 30 μm) and terahertz (THz; 0.3 to 10 THz) spectral regions. Mid-IR QCLs can now operate in continuous-wave (CW) mode at room temperature (RT) with multiwatt output power and high wall-plug efficiencies exceeding 20% ( 2 , 3 ). THz QCL heterostructures embedded in single-plasmon or double-metal waveguides have demonstrated lasing in the 1.2- to 5.4-THz frequency range ( 4 ), with peak output powers that can reach watt levels ( 5 , 6 ).…”

Impact of Cascade Number on the Thermal Properties of Broad‐Area Quantum Cascade Lasers

“…Under an appropriate bias these unipolar devices generate multiple photons per injected electron, thus allowing the gain region to have a larger spatial extent and more overlap with the optical mode. QCLs operate in continuous wave, cw, mode at room temperature and above, can deliver multiple watts of power, and reach room temperature efficiencies approaching 30% . These characteristics together with the extremely narrow emission linewidths make QCLs ideal candidates for a variety of applications including high‐resolution spectroscopy, free‐space communication, health monitoring, and thermal imaging …”