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Despite being a mature technology in existence for over several decades, silicon photonic modulators face scrutiny from industry and academic experts. In a recent editorial interview, experts emphasize the need to explore alternatives beyond the traditional platforms. The discussion centers on innovative modulator materials and configurations that could cater to emerging applications in data centers, artificial intelligence, quantum information processing, and LIDAR. Experts also outline the challenges that lie ahead in this field.

Optical and photonic modulators are technologically advanced devices that enable the manipulation of light properties—such as power and phase—based on input signals. Over the decades, scientists have researched and developed silicon photonic modulators with wide-ranging applications, including optical data communication, sensing, biomedical technologies, automotive systems, astronomy, aerospace, and artificial intelligence (AI).

However, these modulators face bandwidth limitations and operational robustness issues stemming from the fundamental properties of silicon and other practical constraints, as highlighted by a panel of leading industry and academic experts in a recent editorial interview.

Black holes are one of the most enigmatic stellar objects. While best known for swallowing up their surroundings into a gravity pit from which nothing can escape, they can also shoot off powerful jets of charged particles, leading to explosive bursts of gamma rays that can release more energy in mere seconds than our sun will emit in its entire lifetime.

For such a spectacular event to occur, a black hole needs to carry a powerful magnetic field. Where this magnetism comes from, however, has been a long-standing mystery.

Using calculations of black hole formation, scientists at the Flatiron Institute and their collaborators have finally found the origin of those magnetic fields: the collapsing parent stars of the black holes themselves. The researchers report their results November 18 in The Astrophysical Journal Letters.

Banks of computer screens stacked two and three high line the walls. The screens are covered with numbers and graphs that are unintelligible to an untrained eye. But they tell a story to the operators staffing the particle accelerator control room. The numbers describe how the accelerator is speeding up tiny particles to smash into targets or other particles.

However, even the best operator can’t fully track the miniscule shifts over time that affect the accelerator’s machinery. Scientists are investigating how to use computers to make the tiny adjustments necessary to keep particle accelerators running at their best.

Researchers use accelerators to better understand materials and the particles that make them up. Chemists and biologists use them to study ultra-fast processes like photosynthesis. Nuclear and high energy physicists smash together protons and other particles to learn more about the building blocks of our universe.

Recent research by a student-faculty team at Colgate University unlocks new clues that could radically change the world’s understanding of the origin of dark matter.

Assistant Professor of Physics and Astronomy Cosmin Ilie and Richard Casey have explored an idea put forth by two scientists at the University of Texas at Austin, Katherine Freese and Martin Winkler, suggesting that dark matter may have originated from a separate “Dark Big Bang,” occurring shortly after the birth of the universe.

It is widely accepted that all the matter filling our universe (including dark matter) originated from one major event—the Big Bang. This corresponds to the end of the cosmic inflation period, when the vacuum energy that drove the very brief extreme expansion initial phase of our universe was converted into a hot plasma of radiation and particles.

As energy from the sun reaches Earth, some solar radiation is absorbed by the atmosphere, leading to chemical reactions like the formation of ozone and the breakup of gas molecules. A new approach for modeling these reactions, developed by a team led by scientists at Penn State, may improve our understanding of the atmosphere on early Earth and help in the search for habitable conditions on planets beyond our solar system.

The researchers have reported in the journal JGR Atmospheres that using a statistical method called correlated-k can improve existing photochemical models used to understand conditions on early Earth.

The approach can help scientists better understand the atmospheric composition of early Earth and will play an important role as new observatories come online in the coming decades that can provide new data on exoplanet atmospheres, the scientists said.

In a new study, researchers at Osaka University have created the world’s first compact, tunable-wavelength blue semiconductor laser, a significant advancement for far-ultraviolet light technology with promising applications in sterilization and disinfection.

This innovative laser employs a specially-designed periodically slotted structure in nitride semiconductors, making possible a blue wavelength laser that is both practical and adaptable for various disinfection technologies. The work is published in the journal Applied Physics Express.

The research team had previously demonstrated second-harmonic generation at wavelengths below 230 nm by using transverse quasi-phase-matching devices crafted from aluminum nitride and vertical microcavity wavelength conversion devices incorporating SrB₄O₇ nonlinear optical crystals.

A team led by Prof. Lu Zhengtian and Researcher Xia Tian from the University of Science and Technology of China (USTC) realized a Schrödinger-cat state with minute-scale lifetime using optically trapped cold atoms, significantly enhancing the sensitivity of quantum metrology measurements. The study was published in Nature Photonics.

In quantum metrology, particle spin not only serves as a potent probe for measuring magnetic fields, inertia, and a variety of physical phenomena, but also holds the potential for exploring new physics beyond the Standard Model. The high-spin Schrödinger-cat state, a superposition of two oppositely directed and furthest-apart spin states, offers significant advantages for spin measurements.

On one hand, the high spin quantum number amplifies the precession frequency signal. On the other hand, the cat states are insensitive to some environmental interference, thus suppressing measurement noise. However, one major technical challenge in applying cat states in experiments is how to maintain a sufficiently long coherence time.

MIT physicists have shown that it should be possible to create an exotic form of matter that could be manipulated to form the qubit (quantum bit) building blocks of future quantum computers that are even more powerful than the quantum computers in development today.

The work builds on a discovery last year of materials that host electrons that can split into fractions of themselves but, importantly, can do so without the application of a magnetic field. The general phenomenon of electron fractionalization was first discovered in 1982 and resulted in a Nobel Prize.

That work, however, required the application of a magnetic field. The ability to create the fractionalized electrons without a magnetic field opens new possibilities for basic research and makes the materials hosting them more useful for applications.

The first experimental demonstration of two schemes to enhance the longitudinal coherence of SASE-XFEL pulses shows that the SASE pulse bandwidth can be reduced by up to a factor of three.