@article { ISI:000366871100029, title = {New frontiers in quantum cascade lasers: high performance room temperature terahertz sources}, journal = {PHYSICA SCRIPTA}, volume = {90}, number = {11}, year = {2015}, note = {21st Nuclear Physics Workshop on Marie and Pierre Curie, Kazimierz Dolny, POLAND, SEP 23-28, 2014}, month = {NOV}, publisher = {Maria Curie Sklodowska Univ, Dept Theoret Phys}, type = {Article; Proceedings Paper}, address = {TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND}, abstract = {In the last decade quantum cascade lasers (QCLs) have become the most widely used source of mid-infrared radiation, finding large scale applications because of their wide tunability and overall high performance. However far-infrared (terahertz) QCLs have lagged behind in terms of performance and impact due to the inability so far of achieving room temperature operation. Here we review recent research that has led to a new class of QCL light sources that has overcome these limitations leading to room temperature operation in the terahertz spectral range, with nearly 2 mW of optical power and significant tunability, opening up also this region of the spectrum to a wide range of applications.}, keywords = {difference frequency generation, Quantum cascade lasers, terahertz}, issn = {0031-8949}, doi = {10.1088/0031-8949/90/11/118002}, url = {https://iopscience.iop.org/article/10.1088/0031-8949/90/11/118002/meta}, author = {Belkin, Mikhail A. and Federico Capasso} }