Toggle light / dark theme

Deuterium enables chip waveguides to generate broadband light from infrared pulses

A research team from Singapore, led by Associate Professor Dawn Tan of the Singapore University of Technology and Design (SUTD) and Dr. Luo Xianshu, head of the Silicon Photonics Department at the A*STAR Institute of Microelectronics (A*STAR IME), has developed a low-loss silicon nitride waveguide that generates broadband light on a chip. By replacing hydrogen with its heavier isotope, deuterium, the team fabricated the low-loss SiN waveguide on an 8-inch wafer using a low-temperature process, demonstrating its potential for large-scale manufacturing and integration with CMOS-compatible semiconductor processes.

Published in Optics Express, the paper “Octave-spanning supercontinuum generation in a wafer-scale, low loss deuterated silicon nitride waveguide” demonstrates a chip-scale waveguide that stretches infrared laser pulses into a spectrum running from visible red to deep into the infrared.

Lasers are prized for their color purity because they emit light in a single color, but many of the most demanding technologies require a beam that spans an enormous sweep of the spectrum at once. This so-called supercontinuum light underpins high-resolution medical imaging, precision measurement and the frequency combs that keep optical clocks ticking without error.

This Grain-of-Rice-Sized “Rainbow” Chip Could Transform 6G Communications

A tiny chip that produces a precisely organized “rainbow” of light could help enable faster, higher-capacity 6G communications and more precise timing for quantum technologies.

A microchip about the size of a grain of rice can generate a carefully ordered spectrum of light and convert it into multiple high-frequency electromagnetic signals called millimeter waves. Physicists at Loughborough University and their international collaborators say the approach could eventually support technologies that require large amounts of bandwidth and exceptionally precise signals.

Millimeter waves are especially attractive for future communications because they provide far more bandwidth, effectively creating additional capacity for transmitting data. The challenge has been producing these frequencies with the precision and stability required for advanced systems.

Living circuit boards built by printing bacterial transistors

It points toward a future in which computation isn’t necessarily confined to silicon. Instead, we could build living materials that sense, communicate, compute, and respond—with the “circuit board” itself made of living cells.


Electronic circuit boards carry out different operations on the basis of the configuration of their components. Now, equivalent biological circuits are engineered that compute functions on the basis of the spatial arrangement of different bacterial strains printed on a surface.

Quantum dots keep their glow under heat after dual modification

Quantum dots are semiconductor crystals only a few nanometers in size. Their ability to produce bright, precisely tunable colors has made them promising materials for light-emitting diodes, displays, solar cells and other optoelectronic technologies. Yet heat remains a major obstacle to their practical use.

A study from Koç University demonstrates that modifying both the internal crystal lattice and the surface of perovskite quantum dots can substantially improve their thermal stability. While untreated quantum dots began to lose their structural integrity and light emission at around 60°C (140°F), the modified materials remained brightly emissive and retained their cubic structure at temperatures of up to 80°C (176°F).

The open-access study, published in Nanoscale, was conducted by Pouriya Naziri, Saba Sepahban Shahgoli, Hadi Jahangiri and Professor Umut Aydemir of Koç University.

Undersea cable to Antarctica through Drake Passage is viable, researchers find to Chile could spell an end to research data leaving in ‘suitcases full of hard drives’

$370 million to $620 million system would double as a seafloor sensor array.

Scientists discover learning and memory formation in model membranes

“Science is a conversation,” said John Katsaras, neutron scattering scientist at ORNL’s Spallation Neutron Source, a Department of Energy Office of Science user facility. “Many years ago, Pat [Collier] and I wanted to see what would happen when we combined our scientific interests. He wanted to explore soft matter systems for neuromorphic computing [computing systems designed to mimic how the brain processes information], and I’ve studied the structure and dynamics of lipid membranes over the past 40 years. We are now applying decades of our soft matter experience to a problem neither one of us would have imagined pursuing five years ago.”

Soft matter includes materials that readily change shape, such as membranes, gels and polymers. Although biological membranes vary in complexity, they all share a common foundation: a lipid bilayer, or double layer of molecules. Each lipid contains a hydrophilic (water-attracting) head and a hydrophobic (water-repelling) tail.

To study membrane properties under electrical stimulation, Katsaras and Collier used water droplets suspended in oil, known as a droplet interface bilayer. These early experiments showed unexpected electrical data, prompting them to shift their attention to membranes surrounding neurons, where many memory and learning processes occur.

Computer models pinpoint catalysts for replacing fossil-fueled ammonia production

Ammonia is one of the most important chemicals produced in the world, ranking second only to sulfuric acid in the total volume produced each year. It is used mostly to make fertilizer, which is essential to feeding the world’s population. Yet its production accounts for up to 2% of the world’s energy consumption and about 1.5% of greenhouse gas emissions, so the search has been underway for ways to produce ammonia more sustainably.

The traditional way of making ammonia, in use for more than a century and accounting for the vast majority of production, is the Haber–Bosch process, which relies on fossil fuels to provide the needed heat. Hydrogen used in the process is also largely produced from fossil fuels.

There is another way, using electrochemistry instead of heat and pressure, but so far this method has not been anywhere near economically competitive at the scales needed.

This frozen fiber makes light and sound interact 1,000x more strongly

Freezing the liquid core of an optical fiber produced an extreme environment where light and sound interact more than 1,000 times more strongly than in ordinary fibers. Researchers used the effect to create optoacoustic memory, potentially paving the way for lower-energy photonic computers and advanced quantum technologies.

/* */