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Improved laser frequency stabilization achieved with unprecedented long optical reference cavity

Scientists at NPL recently published findings on laser frequency stabilization, demonstrating an unprecedented level of performance using an optical reference cavity. This advancement features a beyond state-of-the-art optical storage time and a novel approach to actively cancel spurious stabilization noise.

Frequency stabilization of lasers to optical reference cavities is a well-established method for achieving superior stability. The recent work, published in Optics Letters, significantly reduces technical stabilization noise, enabling the realization of lasers with enhanced stability performance.

The team developed an optical reference measuring an extraordinary 68 cm in length, achieving a record optical storage time of 300 microseconds. To put this achievement into perspective, the light trapped between the high reflectivity mirrors at either end of the 68 cm cavity can travel approximately 100 kilometers, equivalent to twice the length of the Eurotunnel.

Record-Breaking: Scientists Create Shortest Hard X-Ray Laser Pulses Yet

Researchers used powerful XFELs to trigger strong inner-shell lasing, producing attosecond hard X-ray pulses. Filamentation and Rabi cycling helped explain these effects. Lasers, once confined to the realm of science fiction, are now widely used in research, medicine, and even everyday entertainm

Scientists Achieve “Impossible” Feat in Quantum Measurement

CU Boulder scientists created a quantum device that uses cold atoms and lasers to track 3D acceleration. In a new study, physicists at the University of Colorado Boulder used a cloud of atoms cooled to extremely low temperatures to measure acceleration in three dimensions at the same time, achiev

Scientists Create Exotic “Anyons” in One-Dimensional Quantum Gas

The answer, it turns out, is yes. In a breakthrough experiment, scientists have observed signs of anyons in a one-dimensional ultracold gas for the first time. The research, published in Nature, involved teams from the University of Innsbruck, Université Paris-Saclay, and Université Libre de Bruxelles.

To reveal the presence of anyons, the scientists carefully injected and accelerated a mobile impurity into a tightly controlled gas of bosons at near absolute zero.

Absolute zero is the theoretical lowest temperature on the thermodynamic scale, corresponding to 0.00 K (−273.15 °C or −459.67 °F). At this point, atomic motion ceases entirely, and the substance no longer emits or absorbs thermal energy.

Revolutionizing OLEDs: New Model Unlocks Longer Lifespan and Brighter Displays

Researchers have developed a novel analytical model that reveals the kinetics of exciton dynamics in thermally activated delayed fluorescence (TADF) materials. Organic light-emitting diodes, or OLEDs, are photoluminescence devices that use organic compounds to generate light. Compared to traditio

Natural Plant Extract Removes up to 90% of Microplastics From Water

Researchers found that natural polymers derived from okra and fenugreek are highly effective at removing microplastics from water. The same sticky substances that make okra slimy and give fenugreek its gel-like texture could help clean our water in a big way. Scientists have discovered that these

Physicists Built a “Trampoline” Smaller Than a Human Hair — And It Could Rewrite the Rules of Microchip Design

The world’s strangest trampoline doesn’t bounce—it swings sideways and even glides around corners. But no one can jump on it, because it’s less than a millimeter tall. Imagine a trampoline so tiny it’s just 0.2 millimeters wide, with a surface thinner than anything you’ve ever seen, only about 20

MIT’s Once-a-Week Pill Could Revolutionize Schizophrenia Treatment

The ingestible capsule creates a drug depot in the stomach, slowly releasing its medication over time and removing the need for patients to take a daily dose. For many people living with schizophrenia, other psychiatric conditions, or chronic illnesses like hypertension and asthma, taking medicat

Muon Beams Manipulated

Researchers have demonstrated the slowing and subsequent reacceleration of a muon beam, increasing the potential of muon beams as a research tool.

About every second, the average human has a rare messenger from the edge of space passing through their body. Muons―similar to electrons but with 200 times the mass―are created naturally when cosmic ions strike the upper atmosphere, producing a shower of particles. Muons can also be created artificially, but these muon beams are very sparse compared to more conventional electron, proton, and ion beams. Over the past few decades, researchers have developed a way to make much denser beams [1, 2], but the difficulty of working with such beams has kept scientists from fulfilling their potential as a research tool. Now a team at the Japan Proton Accelerator Research Complex (J-PARC) has successfully demonstrated the capability to manipulate a dense muon beam, accelerating the muons in a radio-frequency device for the first time [3].

Three-dimensional reconstruction of inertial confinement fusion hot-spot plasma from x-ray and nuclear diagnostics on OMEGA

Multidimensional effects degrade the neutron yield and the compressed areal density of laser-direct-drive inertial confinement fusion implosions of layered deuterium–tritium cryogenic targets on the OMEGA Laser System with respect to 1D radiation-hydrodynamic simulation predictions. A comprehensive physics-informed 3D reconstruction effort is under way to infer hot-spot and shell conditions at stagnation from four x-ray and seven neutron detectors distributed around the OMEGA target chamber. Neutron diagnostics, providing measurements of the neutron yield, hot-spot flow velocity, and apparent ion-temperature distribution, are used to infer the mode-1 perturbation at stagnation. The x-ray imagers record the shape of the hot-spot plasma to diagnose mode-1 and mode-2 perturbations. A deep-learning convolutional neural network trained on an extensive set of 3D radiation-hydrodynamic simulations is used to interpret the x-ray and nuclear measurements to infer the 3D profiles of the hot-spot plasma conditions and the amount of laser energy coupled to the hot-spot plasma. A 3D simulation database shows that larger mode-1 asymmetries are correlated with higher hot-spot flow velocities and reduced laser-energy coupling and neutron yield. Three-dimensional hot-spot reconstructions from x-ray measurements indicate that higher amounts of residual kinetic energy are correlated with higher measured hot-spot flow velocities, consistent with 3D simulations.