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Researchers develop novel miniaturized lidar technology based on cross dual-microcomb

Optical frequency combs, as a time and frequency “ruler,” have important applications in precision ranging. Conventional dual-comb ranging schemes utilize the optical Vernier effect to achieve long-distance measurements, and they typically require asynchronously secondary sampling, either after changing the repetition rates or swapping dual-comb roles.

These approaches have a commonly overlooked issue: When considering real-time distance variations induced by target motion or atmospheric turbulence in practical measurement scenarios, the asynchronously secondary sampling will introduce substantial absolute distance measurement error, namely asynchronous measurement error (AME).

In a study published in Science Advances, Prof. Zhang Wenfu’s team from the Xi’an Institute of Optics and Precision Mechanics (XIOPM) of the Chinese Academy of Sciences proposed an on-chip cross dual-microcomb (CDMC) ranging method based on dispersion interferometry. This method resolves the AME issue by eliminating secondary measurements through one-shot spectral sampling of cross dual-microcomb carrying distance information in the frequency domain.

Deep beneath the French Alps, scientists hunt for dark matter

The mysterious substance called dark matter is intrinsically invisible. It cannot be directly observed—rather, its presence is inferred by its gravitational influence on the universe, such as binding galaxy clusters together and moving stars around their galaxy faster than they should.

Cost-effective method developed for high-entropy alloy film production

A collaborative research team has developed a novel method for forming high-performance high-entropy alloy (HEA) films on various surfaces without using expensive alloy targets. This was achieved using a proprietary rotating target composed of multiple pure metal segments and pulsed laser deposition (PLD) technology.

This method uniquely enables not only the deposition of metal atoms onto the substrate surface through laser irradiation but also their implantation into the subsurface, forming robust films that integrate with the substrate material.

Traditionally, producing HEA requires expensive pre-made alloy targets. In contrast, the new method uses inexpensive pure metals, significantly reducing costs. The team also demonstrated precise control of film thickness and depth by adjusting the pressure during deposition.

Scientists Discover Revolutionary New Class of Materials: “Intercrystals”

Scientists at Rutgers University-New Brunswick have identified a new type of material known as intercrystals, which display unusual electronic behaviors that may help shape future technologies.

According to the research team, intercrystals demonstrate electronic characteristics not previously observed, opening the door to progress in areas such as advanced electronic devices, quantum computing.

Quantum computers exploit superposition and entanglement to solve complex problems that are intractable for traditional computers.

Scientists Solve 90-Year-Old Mystery in Quantum Physics

Scientists have discovered a solution to the “damped quantum harmonic oscillator,” paving the way for what could become the world’s tiniest measuring device. A plucked guitar string rings for a few seconds before the sound fades away. A swing on a playground, once its rider steps off, will slowly

Watching Electron Dynamics Shape Chemical Reactions

Scientists have used ultrashort x-ray pulses to directly observe the motion of electrons driving a chemical reaction.

A chemical reaction occurs when chemical bonds break and new ones form. These bonds hold atoms together within molecules and are governed by the atoms’ outermost electrons. The motion of these so-called valence electrons dictates how a reaction starts and determines its final products. For decades, chemists have envisioned the possibility of watching such electron movement in real time, capturing a movie of valence electrons as bonds break and form. Now Ian Gabalski at Stanford University and his colleagues have brought this dream closer to reality [1]. They have observed valence-electron motion occurring within a few hundred femtoseconds—where one femtosecond is a millionth of a billionth of a second. This feat was accomplished using ultrashort, high-energy x-ray pulses produced at SLAC National Accelerator Laboratory in California. The team’s findings provide an intuitive view of how electron dynamics influence chemical reactions.

Directly observing electron motion during chemical reactions presents two main challenges. First, it requires an imaging technique that can map the spatial distribution of electrons, known as the electron density. This distribution spans only a few tenths of a nanometer, demanding extremely high spatial resolution. Second, the task needs ultrahigh temporal resolution, because electron movement occurs on a timescale of femtoseconds or even attoseconds—thousandths of a femtosecond. Capturing such rapid motion requires the sample to be subjected to light pulses that are short enough to effectively freeze electron dynamics in time, similarly to using a high-speed camera to capture the fluttering wings of a hummingbird.

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