An unexpected discovery in a Harvard lab has led to a breakthrough insight into choosing an unconventional material, silica, to make optical metasurfaces – ultra-thin, flat structures that control light at the nanoscale and are already replacing traditional optical devices like lenses and mirrors. A team from Harvard's John A. Paulson School of Engineering and Applied Sciences and collaborators at the University of Lisbon has found that in some cases, silica — the fundamental

In a new Nature Physics study, researchers created particle-like so-called “vortex knots” inside chiral nematic liquid crystals, a twisted fluid similar to those used in LCD screens. For the first time, these knots are stable and could be reversibly switched between different knotted forms, using electric pulses to fuse and split them.

Researchers from TU Delft and Radboud University have discovered that the two-dimensional ferroelectric material CuInP₂S₆ (‘CIPS’) can be used to control the pathway and properties of blue and ultraviolet light like no other material can. With ultraviolet light being the workhorse of advanced chipmaking, high-resolution microscopy and next-generation optical communication technologies, improving the on-chip control over such light is vital. As the researchers describe in the

On the one hand, pixels ranging in size from 100 to 200 nanometres form the foundation for ultra-high-resolution screens that could display razor-sharp images in glasses worn close to the eye, for example. In order to illustrate this, Shih's team of researchers displayed the ETH Zurich logo. This ETH logo consists of 2,800 nano-OLEDs and is similar in size to a human cell, with each of its pixels measuring around 200 nanometres (0.2 micrometres). The smallest pixels developed

The group demonstrated that shining three self-trapped light beams into a specially engineered hydrogel can execute a NAND logic operation, one of the most fundamental building blocks of computing. Because all other digital logic gates can be built from NAND, the achievement establishes soft, photoresponsive materials as a realistic platform for autonomous, computation-capable systems.

A research team at the City University of New York and the University of Texas at Austin has discovered a way to make previously hidden states of light, known as dark excitons, shine brightly, and control their emission at the nanoscale. Their findings, published today in Nature Photonics, open the door to faster, smaller, and more energy-efficient technologies. Dark excitons are exotic light-matter states in atomically thin semiconductors that typically remain invisible beca

Scientists at New York University report the discovery of “gyromorphs”—a material that combines the seemingly incompatible properties of liquids and crystals and that performs better than any other known structure in blocking light from all incoming angles. The breakthrough, described in the journal Physical Review Letters, marks an innovative way to control optical properties and to potentially advance the capabilities of light-based computers.

In the quest for ultra-compact, light-based circuits, scientists are turning to polaritons—hybrid modes formed from the coupling of light with optically active material excitations such as plasmons or phonons. These remarkable quasiparticles can squeeze light into spaces far smaller than its natural wavelength, overcoming the conventional limits of far-field optics. However, exciting most confined variants - higher-order polaritons - has been a major challenge, as they demand

A team of researchers at the Ming Hsieh Department of Electrical and Computer Engineering has created a new breakthrough in photonics: the design of the first optical device that follows the emerging framework of optical thermodynamics. The work, reported in Nature Photonics, introduces a fundamentally new way of routing light in nonlinear systems—meaning systems that do not require switches, external control, or digital addressing. Instead, light naturally finds its way thro

Since the Generalized Snell's Law (GSL) was proposed, planar metasurfaces have achieved remarkable progress in optical and electromagnetic wavefront manipulation by leveraging phase gradients. The Generalized Snell’s Law primarily focuses on the influence of phase gradients on the fundamental wave components while neglecting higher-order spatial harmonics generated by inter-element coupling and periodicity, often limiting metasurfaces to "single-channel" devices and constrain

Caltech team led by Alireza Marandi, a professor of electrical engineering and applied physics at Caltech, has created a tiny device capable of producing an unusually wide range of laser-light frequencies with ultra-high efficiency—all on a microchip.

Researchers have demonstrated a compact, fully integrated device that uses a carefully crafted mirror to generate a stable frequency comb with very broad bandwidth. The mirror they developed, along with an on-chip measurement platform, offers the scalability and flexibility needed for mass-producible remote sensors and portable spectrometers. This development could enable more accurate environmental monitors that can identify multiple harmful chemicals from trace gases in the