Director of Research, Consiglio Nazionale Delle Ricerche, Istituto Nanoscienze, Italy
Terahertz quantum cascade laser frequency combs
Terahertz (THz) frequency technology has stimulated a major surge in interdisciplinary research over the last decade, inspiring both fundamental insights and new applications in microscopicand macroscopic systems,as well as highlighting potential new research avenues in the fields of biomedical imaging, astronomy, security, and high-resolution sensing.
Quantum cascade lasers (QCLs) emitting at THz frequencies have undergone a rapid evolution since their first demonstration, and, in the last few years, have become the best performing, compact THz frequency source in terms of their output power and differential efficiency, frequency tunability, spectral purity and low power consumption. THz QCL can also be engineered with a very broad gain bandwidth, enabling broadband coherent emission as well as the spontaneous formation of THz frequency combs, which have major applications in high-resolution and high-precision spectroscopy and metrology. Furthermore, photonic engineering, combined with new resonator concepts, have enabled the performance of THz QCLs to be designed with an incredible level of control, offering a flexible platform to tailor the emission spectrum, beam profile and output power on-purpose.
This talk will review our recent developments in engineering and devising novel highly efficient broadband QCL resonators, behaving as frequency combs at Terahertz frequencies, with record optical powers per mode and record dynamic range , with a special emphasis on novel integrated architectures.