High-harmonic generation in condensed-matter systems is both a source of fundamental
insight into quantum electron motion and a promising candidate to realize compact …

We present a method to measure quadratic terahertz optical nonlinearities in terahertz time-
domain spectroscopy. We use a rotating linear polarizer (a polarizing chopper) to modulate …

Harmonic generation is a result of a strong non-linear interaction between light and matter. It
is a key technology for optics, as it allows the conversion of optical signals to higher …

The non-linear responses of optical materials offer useful mechanisms for optical switching,
novel optical sources, and harmonic frequency conversion. However, the non-linear …

Third harmonic generation of terahertz radiation is expected to occur in monolayer graphene
due to the nonlinear relationship between the crystal momentum and the current density. In …

The nonlinearities at terahertz (THz) frequencies have been recognized as key and
promising approaches to advance the development of high-frequency THz sources via the …

We report nonlinear terahertz (THz) effects in monolayer graphene, giving rise to
transmission enhancement of a single-cycle THz pulse when the incident THz peak electric …

Advances in the efficient manipulation of terahertz waves are crucial for the further
development of terahertz technology, promising applications in many diverse areas, such as …

A bifunctional metamaterial is proposed based on a hybrid graphene and vanadium dioxide
(VO_2) configuration, which can realize a dynamic switch between beam steering and …

Research into terahertz technology is now receiving increasing attention around the world,
and devices exploiting this waveband are set to become increasingly important in a very …