2 research outputs found
Terahertz Spatiotemporal Wave Synthesis in Random Systems
Complex media have emerged as a powerful and robust framework
to
control light–matter interactions designed for task-specific
optical functionalities. Studies on wavefront shaping through disordered
systems have demonstrated optical wave manipulation capabilities beyond
conventional optics, including aberration-free and subwavelength focusing.
However, achieving arbitrary and simultaneous control over the spatial
and temporal features of light remains challenging. In particular,
no practical solution exists for field-level arbitrary spatiotemporal
control of wave packets. A new paradigm shift has emerged in the terahertz
frequency domain, offering methods for absolute time-domain measurements
of the scattered electric field, enabling direct field-based wave
synthesis. In this work, we report the experimental demonstration
of field-level control of single-cycle terahertz pulses on arbitrary
spatial points through complex disordered media
Resonant Fully dielectric metasurfaces for ultrafast Terahertz pulse generation
Metasurfaces represent a new frontier in materials science paving for unprecedented methods of controlling electromagnetic waves, with a range of applications spanning from sensing to imaging and communications. For pulsed terahertz generation, metasurfaces offer a gateway to tuneable thin emitters that can be utilised for large-area imaging, microscopy and spectroscopy. In literature THz-emitting metasurfaces generally exhibit high absorption, being based either on metals or on semiconductors excited in highly resonant regimes. Here we propose the use of a fully dielectric semiconductor exploiting morphology-mediated resonances and inherent quadratic nonlinear response. Our system exhibits a remarkable 40-fold efficiency enhancement compared to the unpatterned at the peak of the optimised wavelength range, demonstrating its potential as scalable emitter design