Nonlinear harmonic generation of terahertz waves in a topological valley polaritonic microcavity

Generation of second-harmonic conical waves via nonlinear bragg diffraction.

We report on the observation of second-harmonic conical waves generated in a novel geometry of the transverse excitation of an annular periodically poled nonlinear photonic structure by a fundamental Gaussian beam. We show that the conical beams are formed as a result of the higher-order nonlinear Bragg diffraction involving two parametric processes in which an ordinary fundamental wave is conv...

Continuous third harmonic generation in a terahertz driven modulated nanowire

On Nonlinear Water Waves in a Channel

A Quantum Dot Microcavity Terahertz Laser

We discuss a THz laser device based on a semiconductor quantum dot (QD) gain medium, where the lasing occurs through discrete conduction states. An ensemble of QDs is selectively placed in a high quality cavity, called a microdisk, which is resonant with a terahertz intersublevel QD transition. We simulate the rate equations goveming iasing and discuss a variety of processes affecting lasing in...

Terahertz Josephson plasma waves in layered superconductors: spectrum, generation, nonlinear and quantum phenomena

The recent growing interest in terahertz (THz) and sub-THz science and technology is due to its many important applications in physics, astronomy, chemistry, biology and medicine, including THz imaging, spectroscopy, tomography, medical diagnosis, health monitoring, environmental control, as well as chemical and biological identification. We review the problem of linear and nonlinear THz and su...