Photonic engineering of high performance quantum cascade lasers at Terahertz frequencies
Venue: Room A108 - Polo Ferrari 1
At: 14.30
- Prof. Miriam Vitiello - NEST-CNR, Pisa, Italy
Abstract:
Terahertz (THz) technology has prompted in the last decade a major surge of interdisciplinary researches, inspiring fundamental insights and amazing applications in microscopic and macroscopic systems. Being a transition region between electronics and photonics, between component sizes that are smaller and larger than the radiation wavelength, the THz frequency “gap” offers unusual possibilities in borrowing concepts and technologies from fundamentally different worlds.
Recent technological innovation in photonics and nanotechnology is now enabling Terahertz frequency research to be applied in an increasingly widespread range of applications. In this perspective, the availability of compact THz devices that are conveniently single frequency, high-power, low divergent and narrow linewidth laser sources, is matching increasing demand for spectroscopic applications encompassing environmental monitoring, security and biomedical sensing, as well as more fundamental molecular studies and frequency metrology. Quantum cascade lasers (QCLs) operating at terahertz (THz) frequencies have undergone rapid development since their first demonstration. These laser sources can now be designed with high power, broad tunability, high spectral purity, and ultra-broadband gain, leading to a breadth of potential applications ranging from astronomy, security screening, biomedicine, cultural heritage. Typically, continuous-wave (CW) operation is required in THz QCLs, in combination with a low divergent spatial profile in the far-field and a fine spectral control of the emitted radiation. The talk will provide an overview of our recent technological developments of QCLs emitting at THz frequencies, from the engineering of broadband high-power, low divergent 1D and 2D continuous wave QC resonators, to broadly tunable geometries and modulation architectures, with a final overview on THz systems for high precision metrological applications.
