Self-consistent thermal simulation of GaAs/Al0.45Ga0.55As quantum cascade lasers (original) (raw)
Related papers
2016
Your article is protected by copyright and all rights are held exclusively by Springer Science+Business Media LLC. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your work, please use the accepted author’s version for posting to your own website or your institution’s repository. You may further deposit the accepted author’s version on a funder’s repository at a funder’s request, provided it is not made publicly available until 12 months after publication. J Comput Electron DOI 10.1007/s10825-012-0397-8 Self-consistent thermal simulation of GaAs/Al0.45Ga0.55As quantum cascade lasers
Thermal Modelling of Quantum Cascade Lasers
2009
One of the top priorities in the development of quantum cascade laser sources is the optimization of the heat transport dynamic. We review here our experimental studies on the thermal properties of state of art quantum cascade lasers operating both in the mid-IR and THz ranges. The experimental approach is based on the investigation of the band-to-band photoluminescence signals, collected during device continuous wave operation. We measured the lattice temperature profile on the device front facet and using these data as inputs, we extract the heat dissipation patterns, the in-plane and the cross-plane active region thermal conductivities and the thermal boundary resistance for quantum cascade lasers based on different material systems.
Experimental analysis of thermal properties of AlGaAs/GaAs quantum cascade lasers
Semiconductor Lasers and Laser Dynamics V, 2012
We report on detailed investigation of thermal performance of AlGaAs/GaAs quantum cascade lasers (QCL) emitting at wavelength of 9.4 µm, with a particular emphasis on the influence of different mounting options and device geometries, which are compared in terms of their influence on the relative increase of the active region temperature. The spatially resolved thermoreflectance (TR) is used to register temperature distribution over the facet of pulse operated QCLs. The devices' thermal resistances are derived from experimental data. Thermal resistances of 15 µm devices are the highest among the investigated device widths. By combining the experimental and numerical results, an insight into the thermal management in QCLs is gained. The thermal design focuses on optimization of heat dissipation in the device, improving the thermal behavior of QCLs. This is essential in order to increase the maximal operation temperature to further progress the applications of QCLs.
Thermal characteristics of quantum-cascade lasers by micro-probe optical spectroscopy
Iee Proceedings-optoelectronics, 2003
The facet temperature profile and the thermal resistance of operating quantum-cascade lasers (QCLs) have been assessed using a microprobe band-to-band photoluminescence technique. Substrate-side and epilayer-side-mounted QCLs based on GaInAs/AlInAs/InP and GaAs/AlGaAs material systems have been compared. The dependence of the thermal resistance on the CW or pulsed injection conditions and its correlation with the output power have been studied. These results were used as inputs for a two-dimensional heat-diffusion model which gives the heat fluxes and the thermal conductivity of the active regions, in order to design QCLs with improved thermal properties.
Impact of heat dissipation on quantum cascade laser performance
Journal of Applied Physics, 2013
We describe a simple and convenient method to analyze the impact of heating in a quantum-cascade laser on its basic performance characteristics. This method has only one fitting parameter, the thermal resistance of the laser, R th , while the other parameters can be directly measured in pulsed mode. Furthermore, the method can be applied even in the case when lasers do not reach continuouswave operation. The method was used to analyze a quantum-cascade laser emitting at k ¼ 10:6 lm and based on InGaAs-InAlAs material system, lattice-matched to InP. The thermal resistance of R th ¼ 10 K/W determined using the described method and the flat active region shape imply a vertical thermal conductivity value of j ? ¼ 0:53 W=m Á K for the lattice-matched InGaAs-InAlAs active region, which agrees well with literature values. V C 2013 American Institute of Physics.
Thermal effects in InGaAs/AlAsSb quantum-cascade lasers
IEE Proceedings - Optoelectronics, 2006
A quantum cascade laser (QCL) thermal model is presented. Based upon a finite-difference approach, the model is used in conjunction with a self-consistent carrier transport model to calculate the temperature distribution in a near-infrared InGaAs/AlAsSb QCL. The presented model is used to investigate the effects of driving conditions and device geometries on the active region temperature, which has a major influence on the device performance. A buried heterostructure (BH) combined with epilayer-down bonding is found to offer the best performance compared to alternative structures and has thermal times constants up to eight times smaller. The presented model provides a valuable tool for understanding the thermal dynamics inside a QCL and will help to improve operating temperatures.
Influence of leakage current on temperature performance of GaAs/AlGaAs quantum cascade lasers
Applied Physics Letters, 2002
A detailed analysis of intersubband electron scattering transport in GaAs/AlGaAs quantum cascade lasers, using a full self-consistent rate equations analysis, is presented. Our approach includes all relevant scattering mechanisms between injector/collector, active region and continuum-like states in the cascade structures. In particular, the influence of the Al mole fraction in the quantum barriers on the thermally induced leakage current from the injector via continuum-like levels is investigated. It is found that increasing the Al mole fraction from 33% to 45% significantly affects the device output characteristics, and decreases the injection losses in the higher current-room temperature operating regime. Exellent qualitative and quantitative agreement with recent experimental results at cryogenic and room temperatures is obtained. ! 300 K. cordance with the experimentally obtained losses 14 from the intersection points of the total loss line α M © α W % 30 cm 1 and the G M J lines, we obtain the threshold current J th % 6 kA/cm 2 at T 77 K. Both g and J th are in very good agreement with experiment (g 8 7 kA/cm and J th 4
Photonics
In this paper, we report on the experimental investigation of the thermal performance of lattice matched AlInAs/InGaAs/InP quantum cascade lasers. Investigated designs include double trench, single mesa, and buried heterostructures, which were grown by combined Molecular Beam Epitaxy (MBE) and Metal Organic Vapor Phase Epitaxy (MOVPE) techniques. The thermal characteristics of lasers are investigated by Charge-Coupled Device CCD thermoreflectance. This method allows for the fast and accurate registration of high-resolution temperature maps of the whole device. We observe different heat dissipation mechanisms for investigated geometries of Quantum Cascade Lasers (QCLs). From the thermal point of view, the preferred design is the buried heterostructure. The buried heterostructures structure and epi-layer down mounting help dissipate the heat generated from active core of the QCL. The experimental results are in very good agreement with theoretical predictions of heat dissipation in various device constructions.