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The Progress and Trend of Heterogeneous Integration Silicon/III-V Semiconductor Optical Amplifiers

Silicon photonics is a revolutionary technology in the integrated photonics field which has experienced rapid development over the past several decades. High-quality III-V semiconductor components on Si platforms have shown their great potential to realize on-chip light-emitting sources for Si photonics with low-cost and high-density integration. In this review, we will focus on semiconductor optical amplifiers (SOAs), which have received considerable interest in diverse photonic applications. SOAs have demonstrated high performance in various on-chip optical applications through different integration technologies on Si substrates. Moreover, SOAs are also considered as promising candidates for future light sources in the wavelength tunable laser, which is one of the key suitable components in coherent optical devices.

Nanodevice uses sound to sculpt light, paving the way for better displays and imaging

Light can behave in very unexpected ways when you squeeze it into small spaces. In a paper in the journal Science, Mark Brongersma, a professor of materials science and engineering at Stanford University, and doctoral candidate Skyler Selvin describe the novel way they have used sound to manipulate light that has been confined to gaps only a few nanometers across—allowing the researchers exquisite control over the color and intensity of light mechanically.

The findings could have broad implications in fields ranging from computer and virtual reality displays to 3D holographic imagery, optical communications, and even new ultrafast, light-based neural networks.

The new device is not the first to manipulate light with sound, but it is smaller and potentially more practical and powerful than conventional methods. From an engineering standpoint, acoustic waves are attractive because they can vibrate very fast, billions of times per second.

Simulations reveal surprising electron temperatures near M87 black hole’s event horizon

The first black hole images stunned the world in 2019, with headlines announcing evidence of a glowing doughnut-shaped object from the center of galaxy Messier 87 (M87 —55 million light years from Earth. Supercomputer simulations are now helping scientists sharpen their understanding about the environment beyond a black hole’s ‘shadow,’ material just outside its event horizon.

Internal pair production could enable direct detection of dark matter

Dark matter (DM) is a type of matter estimated to account for 80% of the universe’s total mass, but it cannot be directly detected using conventional experimental techniques. As DM does not emit, reflect or absorb light, most previous dark matter searches were aimed at observing either its weak interactions with ordinary matter using highly sensitive detectors or other signatures linked to its presence or decay.

Researchers at Texas A&M University recently introduced a new approach that could enable the direct detection of this elusive type of matter, leveraging a process known as the DM internal pair production. Their proposed strategy, outlined in a paper published in Physical Review Letters, could open new possibilities for future DM searches focusing on a wide range of candidate particles.

“The particle nature of DM can be revealed when a DM particle scatters off a nucleus and produces a visible recoil signal,” the authors told Phys.org. “However, for light DM, transferring sufficient energy to a heavy nucleus is kinematically challenging, even if the DM is energetic. To overcome this limitation, we developed a framework where additional particles are produced in the final state, allowing the DM’s energy to be shared among them, while the nucleus remains largely at rest.”

Single salt crystals seen creeping across surfaces below liquid for first time

Salt creeping, a phenomenon that occurs in both natural and industrial processes, describes the collection and migration of salt crystals from evaporating solutions onto surfaces. Once they start collecting, the crystals climb, spreading away from the solution. This creeping behavior, according to researchers, can cause damage or be harnessed for good, depending on the context.

New research published June 30 in the journal Langmuir is the first to show salt creeping at a single-crystal scale and beneath a liquid’s meniscus.

“The work not only explains how salt creeping begins, but why it begins and when it does,” says Joseph Phelim Mooney, a postdoc in the MIT Device Research Laboratory and one of the authors of the new study. “We hope this level of insight helps others, whether they’re tackling , preserving ancient murals, or designing longer-lasting infrastructure.”

Dome-shaped aerogel architecture offers superior toughness and flexibility for spacecraft applications

A new collection of chemically diverse dome-celled ultralight aerogels with high porosity and very low density feature elasticity and mechanical properties that remain intact even under extreme temperatures from 4.2 kelvin (K) to 2273 K.

Scientists create first programmable single-atom catalyst that adapts chemical activity

A research team at the Politecnico di Milano has developed an innovative single-atom catalyst capable of selectively adapting its chemical activity. This is a crucial step forward in sustainable chemistry and the design of more efficient and programmable industrial processes.

The study was published in the Journal of the American Chemical Society.

This achievement is novel in the field of single-atom catalysts. For the first time, scientists have demonstrated the possibility of designing a material that can selectively change its catalytic function depending on the chemical environment. It involves a sort of “molecular switch” that allows complex reactions to be performed more cleanly and efficiently, using less energy than conventional processes.

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