Low Frequency and Circuit based Quantum Cascade Lasers

The book explores the development of quantum cascade lasers, focusing on their operation from above 100 THz to the terahertz region, which lacks efficient narrowband sources. It details a low frequency design achieving a record operation frequency of 1.2 THz and introduces a hybrid laser-oscillator combining an optical gain medium with an electronic resonator. This innovative circuit-based laser features a deep sub-wavelength microcavity, enabling new devices for generating and manipulating terahertz radiation through cavity quantum electrodynamic effects.