Electro-optic modulators change the intensity of light in response to electric signals and have attracted much attention recently as they enable active photonics. Reaching gigahertz speeds is an important milestone that makes applications in remote sensing and communications accessible. Most demonstrations target either on-chip or fiber applications. Instead, modulators that operate on free-space light have long been very challenging to realize. Here, we show that a thin film metasurface from sub-wavelength Mie resonators enables highly efficient and ultra-compact modulation of light up...

Current achromatic metalenses are typically small and bounded to tens to hundreds of micrometers in diameter – the size of a few pollen grains in a row. In this study, we demonstrate a high throughput inverse design framework that is able to design large-scale complex metasurfaces to the cm scale for the visible, which corresponds to 20 000 times the wavelengths. The inverse design framework takes advantage of machine intelligence instead of our physical intuition, and the whole process takes less than a day using a single-CPU laptop, making it accessible to the general public. The...

In recent work, we have shown that a suitably-designed polarization-sensitive metasurface grating when paired with a conventional imaging system can serve as an "attachment" rendering it capable of polarization imaging. We describe the design rules that govern this process, and show as an example the adaptation of a simple machine vision camera with a metasurface grating.

More broadly, the work serves as a guide to using metasurface polarization gratings in optical systems more generally. These may be used as a polarization-sensitive component in a wide variety of contexts,...

Terahertz radiation lies in the transition region between the microwave and infrared spectra. It has much potential in civil and defence applications, including communications, imaging, and spectroscopy. Yet, the major obstacle to the widespread use of this spectrum has...

The peculiar physics of quantum cascade lasers has led to the discovery of new frequency comb phenomena beyond traditional ones such as harmonic states, characterized by mode skipping, time-dependent spatial hole burning, turbulent states, recently observed in ring cavities, just to mention a few. These new types of frequency combs open technological and fundamental perspectives, such as laser radio applications and deep connections with passive Kerr microresonators, which are the object of our review.

See the publication on Laser and Photonics Reviews...

Optical vortices —light structures which look like donuts and can rotate around their axis of propagation— have attracted wide interest as new means for free space communications, optical trapping, and structured illumination in microscopes. Current wavefront shaping methods, however, can only provide limited control over the vorticity and the polarization (photon’s spin) of those beams in 3D space, thus limiting their application. In this study, we introduce a new type of metasurfaces which can generate complex optical vortices in which both the vortex strength and polarization state...