Tag Archives: lasers

Spiral Lasers Can Manage Their Unruly Magnetic Counterparts

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Materials resembling magnets exhibit internal spirals that can solely be controlled with circularly polarized lasers.

Andrew Ostrovsky/iStockphoto/Getty Images

Scientists have successfully regulated the behavior of a previously elusive material, akin to magnetism, which may eventually lead to improved hard drives.

When a bar magnet is introduced to a magnetic field, it rotates due to that influence. However, materials characterized by a property called strong axis remain stationary under all known magnetic fields. Recently, Zeng Zhiyang and his team at the Max Planck Institute for the Structure and Mechanics of Matter in Germany discovered a method to manipulate strong-axis properties using lasers.

A conventional magnetic material is often thought of as a collection of many small bar magnets. Zeng explains that for strong-axis materials, it is more accurate to envision a group of dipoles (two opposing charges separated by a small distance) swirling in a minor spiral. He and his team realized they could control these vortices with laser pulses containing a specific swirl.

The researchers adjusted the laser to emit circularly polarized light. Upon striking a strong-axis material (specifically a compound made of rubidium, iron, molybdenum, and oxygen), it induced rotation in the material’s atoms, altering the dipole’s direction of motion.

Team member Michael Forst from the Max Planck Institute for Structure and Mechanics of Matter remarked that while it has been established that light can effectively control materials—transforming conductors into insulators and vice versa—tailoring light’s properties for material control has presented a significant technical challenge.

“This serves as a strong proof of concept,” notes Theo Rasing at Radboud University in the Netherlands. He adds that this material adds to the growing array of options for constructing more efficient and stable memory devices, such as hard drives that store information in electromagnetic charge patterns.

However, the current experiments necessitate cooling the material to approximately -70°C.°C (-94°F). Additionally, because the team’s laser was relatively large, Forst indicates that more development is required before a practical device can realistically be constructed.

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Source: www.newscientist.com

Using Lasers, Fiber Optics, and Subtle Vibrations to Develop Earthquake Warning Systems

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When the Mendocino earthquake erupted off the California coast in 2024, it shook structures from their very foundations, triggered a 3-inch tsunami, and sparked intriguing scientific investigations in the server room of a nearby police station.

More than two years prior to the quake, scientists had installed a device known as the “Dispersed Acoustic Sensing Interrogation Room” at the Alcata Police Station located near the coast. This device utilizes a laser directed through a fiber optic cable that provides internet connectivity to the station, detecting how the laser light bends as it returns.

Recently, researchers revealed in a study published in the Journal Science that data collected from fiber optic cables can effectively be used to “image” the Mendocino earthquake.

This research demonstrates how scientists can convert telecommunication cables into seismometers, providing detailed earthquake data at the speed of light. Experts noted that this rapidly advancing technology has the potential to enhance early earthquake warning systems, extending the time available for individuals to take safety measures, and could be critical for predicting major earthquakes in the future.

James Atterholt, a research geophysicist for the US Geological Survey and lead author of the study, stated, “This is the first study to image the seismic rupture process from such a significant earthquake. It suggests that early earthquake warning alerts could be improved using telecom fibers.”

The study proposes equipping seismometers with devices capable of gathering sparse data from the extensive network of telecommunications cables utilized by companies such as Google, Amazon, and AT&T, making monitoring submarine earthquakes—often costly—more affordable.

Emily Brozky, a professor of geoscience at the University of California, Santa Cruz, asserted that “early earthquake warnings could be dramatically improved tomorrow” if scientists can establish widespread access to existing communication networks.

“There are no technical barriers to overcome, and that’s precisely what Atterholt’s research emphasizes,” Brozky mentioned in an interview.

In the long term, leveraging this technology through fiber optic cables could enable researchers to explore the possibility of forecasting some of the most devastating earthquakes in advance.

Scientists have observed intriguing patterns in underwater subduction zones prior to significant earthquakes, including Chile’s magnitude 8.1 quake in 2014 and the 2011 Tohoku earthquake and tsunami in Japan.

Both of these major earthquakes were preceded by what are known as “slow slip” events that gradually release energy over weeks or months without causing noticeable shaking.

The scientific community is still uncertain about what this pattern signifies, as high-magnitude earthquakes (8.0 or greater) are rare and seldom monitored in detail.

Effective monitoring of seismic activity using telecommunications networks could enable scientists to accurately document these events and assess whether discernible patterns exist that could help predict future disasters.

Brodsky remarked, “What we want to determine is whether the fault will slip slowly before it gives way entirely. We keep observing these signals from afar, but what we need is an up-close and personal instrument to navigate the obstacles.”

While Brodsky emphasized that it’s still unclear whether earthquakes in these extensive subduction zones can be predicted, she noted that the topic is a major source of scientific discussion, with the new fiber optic technology potentially aiding in resolving this issue.

For nearly 10 years, researchers have been investigating earthquake monitoring through optical fiber cables. Brodsky stated that the study highlights the need for collaboration among the federal government, scientific community, and telecommunications providers to negotiate access.

“There are valid concerns; they worry about people installing instruments on their highly valuable assets and about the security of cables and privacy,” Brozky explained regarding telecom companies. “However, it is evident that acquiring this data also serves the public’s safety interests, which makes it a regulatory issue that needs to be addressed.”

Atterholt clarified that fiber optic sensing technology is not intended to replace traditional seismometers, but rather to complement existing data and is more cost-effective than placing seismometers on the seabed. Generally, using cables for earthquake monitoring does not interfere with their primary function of data transmission.

Jiaxuan Li, an assistant professor of geophysics and seismology at the University of Houston, noted he was not involved in the study but mentioned that there are still technical challenges to the implementation of distributed acoustic sensing (DAS) technology, which currently functions over distances of approximately 90 miles.

Li also pointed out that similar methods are being employed in Iceland to monitor magma movements in volcanoes.

“We utilized DAS to facilitate early warnings for volcanic eruptions,” Li explained. “The Icelandic Meteorological Office is now using this technology for issuing early alerts.”

Additionally, the technique indicated that the Mendocino tremors were rare “supershear” earthquakes, which occur when fault fractures advance quicker than seismic waves can travel. Atterholt likened it to a fighter jet exceeding the speed of sound.

New research has serendipitously uncovered patterns associated with Mendocino, providing fresh insights into this phenomenon.

“We still have not fully grasped why some earthquakes become supershear while others do not,” Atterholt reflected. “This could potentially alter the danger level of an earthquake, but the correlation remains unclear.”

Source: www.nbcnews.com

Physicists Unveil the Concept of Neutrino Lasers

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Researchers from MIT and the University of Texas at Arlington suggest that supercooling radioactive atoms may enable the creation of laser-like neutrino beams. They illustrate this by calculating the potential for a neutrino laser using one million rubidium-83 atoms. Generally, the half-life of a radioactive atom like this is approximately 82 days, indicating that half of the atoms will decay and emit an equal number of neutrinos within that timeframe. Their findings indicate that cooling rubidium-83 to a stable quantum state could allow for radioactive decay to occur in only a few minutes.

BJP Jones & Ja Formaggio devises the concept of a laser that emits neutrinos. Image credit: Gemini AI.

“In this neutrino laser scenario, neutrinos would be released at a significantly accelerated rate, similar to how lasers emit photons rapidly.”

“This offers a groundbreaking method to enhance radioactive decay and neutrino output. To my knowledge, this has never been attempted before,” remarked MIT Professor Joseph Formaggio.

A few years ago, Professor Formaggio and Dr. Jones were each considering unique opportunities in this field. They pondered: could we amplify the natural process of neutrino generation through quantum consistency?

Their preliminary research highlighted several fundamental challenges to achieving this goal.

Years later, during discussions regarding the properties of ultra-cold tritium, they asked: could enhancing qualitatively the quantum state of radioactive atoms like tritium lead to improved neutrino production?

The duo speculated that transitioning radioactive atoms into Bose-Einstein condensates might promote neutrino generation. However, during quantum mechanical calculations, they initially concluded that such effects might not be feasible.

“It was a misleading assumption; merely creating a Bose-Einstein condensate does not speed up radioactive decay or neutrino production,” explained Professor Formaggio.

Years later, Dr. Jones revisited the concept, incorporating the phenomenon of Superradiance. This principle from quantum optics occurs when groups of luminescent atoms are synchronously stimulated.

It is anticipated that in this coherent state, the atoms will emit a burst of superradiant or more radioactive photons than they would if they were not synchronized.

Physicists suggest that analogous superradiant effects may be achievable with radioactive Bose-Einstein condensates, potentially leading to similar bursts of neutrinos.

They turned to the equations governing quantum mechanics to analyze how light-emitting atoms transition from a coherent state to a superradiant state.

Using the same equations, they explored the behavior of radioactive atoms in a coherent Bose-Einstein condensed state.

“Our findings indicate that by producing photons more rapidly and applying that principle to neutrinos, we can significantly increase their emission rate,” noted Professor Formaggio.

“When all the components align, the superradiation of the radioactive condensate facilitates this accelerated, laser-like neutrino emission.”

To theoretically validate their idea, the researchers calculated the neutrino generation from a cloud of 1 million supercooled rubidium-83 atoms.

The results showed that in the coherent Bose-Einstein condensate state, atoms can reduce radioactivity at an accelerated rate, releasing a laser-like stream of neutrinos within minutes.

Having demonstrated that neutrino lasers are theoretically feasible, they plan to experiment with a compact tabletop setup.

“This should involve obtaining the radioactive material, evaporating, laser-trapping, cooling, and converting it into a Bose-Einstein condensate,” said Jones.

“Subsequently, we must instigate this superradiance.”

The pair recognizes that such experiments will require extensive precautions and precise manipulation.

“If we can demonstrate this in the lab, it opens up possibilities for future applications. Could this serve as a neutrino detector? Or perhaps as a new form of communication?”

Their paper has been published today in the journal Physical Review Letters.

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BJP Jones & Ja Formaggio. 2025. Super radioactive neutrino lasers from radioactive condensate. Phys. Pastor Rett 135, 111801; doi:10.1103/l3c1-yg2l

Source: www.sci.news

Using lasers to transform electrons into mass and charge coils.

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A special laser (red) can bend electrons (blue) into a spiral shape

Dr. Yiqi Fan (University of Konstanz)

With the help of a laser, the electrons were transformed into spiral waves of mass and charge.

“Chirality, or handedness, is an intriguing and still partially mysterious feature of our universe.” Peter Baum Researchers at the University of Konstanz in Germany have discovered that chiral objects, like coils or L-shaped blocks, can be either left- or right-handed, but non-chiral objects, like circles or lines, cannot. Many molecules and materials are inherently chiral, and their function changes depending on whether they are right- or left-handed. But Baum and his colleagues have devised a way to impart chirality to something very small and fundamental: a single electron.

Because electrons are quantum objects, they exhibit both particle-like and wave-like behavior, depending on the experiment. In this experiment, the researchers exploited the wave nature of electrons. First, they create a very fast pulse of electrons and pass it through a thin ceramic membrane. There, the particles encounter a special laser beam. The beam is shaped like a light vortex and, as a result, carries a similarly shaped electromagnetic field. This electromagnetic field affects the wave function, or wave properties, of each electron that passes through it.

Finally, the researchers detected these manipulated electrons and calculated the “expectation values” of each of their masses and charges — that is, the places in space where both properties are most likely to be measured in non-zero quantities. These regions of space formed the shape of a three-dimensional coil, with clearly marked left- or right-handed winding.

Ben McMorran The University of Oregon researchers have previously experimented with making coils of chiral electrons, and they say their new work “represents a very advanced advancement in the state of the art of shaping electrons.” They have demonstrated precise control over the spiraling electrons, which they say will be crucial for using the particles in applications such as imaging and controlling existing materials.

Baum and his colleagues have already found that shining a left-handed coil of electrons at right-handed gold nanostructures results in different ricochet patterns than shining it on left-handed structures, opening up the possibility of using such coils to selectively affect chiral moieties in chemical compounds or electronic devices.

Having created these strange electrons in the lab, Baum says he's now interested in whether they could arise independently in nature: “We're starting to explore these possibilities.”

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Source: www.newscientist.com

The impact of chip-integrated lasers on the field of photonics

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Chip-scale ultrafast mode-locked laser based on nanophotonic lithium niobate.Credit: Alireza Marandi

Researchers have developed a compact mode-locked laser integrated into a nanophotonic platform that can generate ultrafast light pulses at high power. This breakthrough in the miniaturization of MLL technology has the potential to significantly expand photonics applications.

Innovation in mode-locked laser technology

Setting out to improve a technology that typically requires bulky benchtop equipment, Quishi Guo and colleagues have miniaturized a mode-locked laser (MLL) with an integrated nanophotonics platform to the size of an optical chip. This result shows promise for the development of ultrafast nanophotonics systems for a wide range of applications.

Possibility of small MLL

Model-locked lasers (MLLs) can generate coherent ultrashort pulses of light at very fast speeds on the order of picoseconds to femtoseconds. These devices have enabled numerous techniques in the field of photonics, including extreme nonlinear optics.photon Microscopy and optical computing.

However, most MLLs are expensive, power-hungry, and require bulky, separate optical components and equipment. As a result, the use of ultrafast photonic systems has generally been limited to benchtop laboratory experiments. Furthermore, so-called “integrated” MLLs aimed at driving nanophotonics platforms have significant limitations, such as low peak power and lack of controllability.

Breakthrough advances in nanophotonics MLL integration

Through hybrid integration of semiconductor optical amplification chips and novel thin-film lithium niobate nanophotonic circuits, Guo other. We created an optical chip-sized integrated MLL.

According to the authors, this MLL generates ultrashort light pulses of about 4.8 picoseconds at about 1065 nanometers with a maximum output of about 0.5 watts. This is the highest output pulse energy and peak power of any MLL integrated into a nanophotonics platform.

Furthermore, the researchers show that the repetition rate of the integrated MLL can be tuned over a range of about 200 MHz and that the coherence properties of the laser can be precisely controlled, creating a fully stable on-chip nanophotonic frequency comb source. provided a path to.

Learn more about this breakthrough advancement below.

Reference: “Ultrafast mode-locked lasers in nanophotonic lithium niobate” Qiushi Guo, Benjamin K. Gutierrez, Ryotosekine, Robert M. Gray, James A. Williams, Luis Ledezma, Luis Costa, Arkadev Roy, Selina Zhou, Mingchen Liu, and Alireza Marandi, November 9, 2023; science.
DOI: 10.1126/science.adj5438

Source: scitechdaily.com

The process of using lasers to transform moon dust into roads

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ESA’s PAVER project aimed to create paved surfaces on the lunar surface using melted lunar regolith. They conducted ground-based tests using a carbon dioxide laser and are planning to use a Fresnel lens on the Moon to focus sunlight. The successful use of lasers to melt simulated lunar dust is a significant development in addressing the challenges posed by lunar dust in future missions.

The construction of roads on the lunar surface is essential for astronauts who will likely be driving rather than walking during their missions. Lunar dust is fine, abrasive, and sticky, leading to equipment damage and spacesuit corrosion. For example, the Apollo 17 lunar rover overheated when its rear fender was lost and replaced with a lunar map, covered in kicked-up dust. The Soviet Lunokod 2 rover experienced a similar fate, dying from overheating after its radiator became covered in dust.

To prevent the accumulation of lunar dust, it is necessary to pave active areas on the Moon, including roads and landing pads. The idea of melting sand to create roads was originally proposed in 1933. ESA’s PAVER project, led by Germany’s BAM Institute for Materials Testing in collaboration with Aalen University, LIQUIFER Systems Group, and the University of Claustal in Austria and Germany, investigated the feasibility of building lunar roads using a similar approach. The project received support from the Institute for Space Materials Physics of the German Aerospace Center (DLR).

The PAVER consortium utilized a 12-kilowatt carbon dioxide laser to melt simulated lunar dust and create a glassy solid surface that can serve as a paved surface on the Moon. They achieved spot sizes of 5 to 10 cm in their trials. By utilizing a 4.5 cm diameter laser beam, they developed a strategy to produce a triangular hollow-centered geometry of about 20 cm in diameter. This approach allowed them to create solid surfaces over large areas of lunar soil suitable for roads or landing pads.

The project’s materials engineer, Advenit Makaya, explained that the current laser used in their experiment functions as a light source instead of lunar sunlight. To achieve equivalent melting on the lunar surface, the laser light would be focused using a Fresnel lens with a diameter of several meters.

The PAVER consortium’s methodology involved trial and error to determine the optimal laser beam size and geometry. They found that larger spot sizes were easier to work with, as heating on a millimeter scale produced challenging agglomeration due to surface tension. With their approach, they were able to create a stable layer of molten regolith, which could be better controlled. The resulting material is glassy and brittle but can withstand primarily downward compressive forces, potentially being repaired if needed.

The research team discovered that reheating a cooled track could cause cracks, leading them to minimize crossover in the geometry. The depth of a single melt layer achieved was approximately 1.8 cm. Depending on the required loads, the constructed structures and roads could consist of multiple layers.

The PAVER consortium estimated that a 100 square meter landing pad with a 2 cm thick high-density material could be constructed in 115 days using their approach.

The PAVER project originated from a call for ideas conducted by ESA’s Basic Activities Discovery Division through the Open Space Innovation Platform (OSIP). Out of 69 submissions, 23 ideas were implemented, including the PAVER project. The project has opened up promising avenues for future research in extraterrestrial manufacturing and construction.

Overall, the successful use of lasers to melt lunar dust represents a significant advancement towards the construction of roads and landing pads on the lunar surface, addressing the challenges posed by lunar dust in future lunar missions.

Source: scitechdaily.com