In this roadmap article, we have focused on the most recent advances in terahertz (THz)
imaging with particular attention paid to the optimization and miniaturization of the THz …

The dynamics of semiconductor lasers with fast gain is generally considered to suppress
amplitude modulation, resulting in a frequency‐modulated output. Since their first …

In many laser systems, frequency combs whose output is frequency-modulated (FM) can
form, producing light whose frequency sweeps linearly. While this intriguing result has been …

It was recently demonstrated that broadband quantum cascade lasers can operate as
frequency combs. As such, they operate under direct electrical pumping at both mid-infrared …

The generation of stable trains of ultrashort (femtosecond to picosecond), terahertz-
frequency radiation pulses with large instantaneous intensities is an underlying requirement …

Photoacoustic dual-comb spectroscopy (DCS), converting spectral information in the optical
frequency domain to the audio frequency domain via multi-heterodyne beating, enables …

Wave instability—the process that gives rise to turbulence in hydrodynamics—represents
the mechanism by which a small disturbance in a wave grows in amplitude owing to …

On-chip integration of optical comb sources is crucial in enabling their widespread use.
Integrated photonic devices that can be mass-manufactured in semiconductor processing …

Generating optical combs in a small form factor is of utmost importance for a wide range of
applications such as datacom, LIDAR, and spectroscopy. Electrically powered mode‐locked …

Chip‐scale, electrically‐pumped terahertz (THz) frequency‐combs (FCs) rely on nonlinear
four‐wave‐mixing processes, and have a nontrivial phase relationship between the evenly …