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Coupling mechanical motion to an optical resonator enables displacement measurements approaching the standard quantum limit (SQL). However, increasing the optomechanical coupling strength will inevitably lead to probing of the nonlinear response of the optical resonator. Thermal intermodulation noise (TIN) arising from the nonlinear mixing of thermomechanical motion can further increase the imprecision well above the SQL and has hitherto been canceled up to second order of nonlinearity via operation at the "magic detuning". In this work, we record the output of a membrane-in-the-middle microcavity system operating at room temperature and achieving high cooperativity, $C>n_\text{th}$, and apply a nonlinear transform that removes all orders of TIN, improving the mechanical signal-to-noise ratio by nearly 10 dB. Our results can be applied to experiments affected by third-order TIN, which we expect to be the dominating intrinsic source of noise in high-cooperativity room-temperature cavity optomechanical systems.

High-quality microring resonators (MRRs) have proven to be promising sources of optical combs generated from continuous-wave radiation. In addition to the primary comb that propagates along with the pump, Rayleigh scattering creates a comb that travels in the opposite direction. Normally, the scattering is a very weak, however, in the high-quality-factor MRR the power transferred to the backward-propagating comb can be quite significant. We demonstrate that the backward-propagating comb can be used as a feedback source for a fiber laser, effectively creating a nonlinear mirror for the laser cavity. By assembling a simple laser cavity comprising only active fiber and two mirrors, one of which is an integrated MRR, we show a robust self-starting comb generation with width exceeding 500 nm. We confirm the universal character of this approach for other types of microresonators, including whispering gallery mode resonators, by launching self-starting laser cavity combs with the crystalline toroidal cavity, coupled with a tapered fiber. This method provides significant simplification for the filter-driven laser cavity soliton generation, especially when free-space coupling is applied.

Landmine detection using traditional methods is slow, dangerous and prohibitively expensive. Using deep learning-based object detection algorithms drone videos is promising but has multiple challenges due to the small, soda-can size of recently prevalent surface landmines. The literature currently lacks scientific evaluation of optimal ML models for this problem since most object detection research focuses on analysis of ground video surveillance images. In order to help train comprehensive models and drive research for surface landmine detection, we first create a custom dataset comprising drone images of POM-2 and POM-3 Russian surface landmines. Using this dataset, we train, test and compare 4 different computer vision foundation models YOLOF, DETR, Sparse-RCNN and VFNet. Generally, all 4 detectors do well with YOLOF outperforming other models with a mAP score of 0.89 while DETR, VFNET and Sparse-RCNN mAP scores are all around 0.82 for drone images taken from 10m AGL. YOLOF is also quicker to train consuming 56min of training time on a Nvidia V100 compute cluster. Finally, this research contributes landmine image, video datasets and model Jupyter notebooks at https://github.com/

Scientists have generated quantum entanglement directly from sunlight, potentially offering a lower-energy alternative to the lasers normally used in quantum technology。 Their outdoor experiment produced entangled photons with about 94% similarity to an ideal state。 The result could pave the way for simpler quantum satellites, secure communications

A black hole observed during a dramatic 2023 eruption did not simply devour gas from its nearby companion star。 It also expelled large amounts of material through powerful jets and winds, even after the outburst had nearly faded。 The results suggest black holes may continue reshaping their surroundings long after their brightest fireworks end

Ultrafast X-rays revealed how a molecule converts absorbed light into motion in just trillionths of a second。 Individual atoms recorded different stages of the process, opening a powerful new window into light-driven chemistry

A massive magma reservoir has been detected deep beneath Tuscany, despite showing no obvious signs at the surface。 Scientists mapped the roughly 6,000-cubic-kilometer body using natural ground vibrations recorded by dozens of seismic sensors。 It poses no immediate danger, but the discovery reveals how enormous volcanic systems can remain hidden and

Hidden moon ice may reveal itself through the way it bends and reflects vibrations from moonquakes。 The technique could help astronauts locate vital water supplies and uncover clues about the origins of Earth’s oceans

Scientists have built the first all-optical photonic time crystal, allowing them to reshape the behavior of terahertz light at extraordinary speeds。 The breakthrough could open the door to ultrafast computing, smarter communication systems, advanced imaging, and a new generation of highly tunable lasers

Mathematicians have shown that no electoral system can perfectly balance local representation, proportional national results, and a fixed-size parliament once enough parties compete。 A newly proposed voting method could soften these unavoidable trade-offs and produce outcomes that are much closer to fair

We expected them to be there, but they had previously been too small to see

A supermassive black hole has been found lurking about 30,000 light-years from the center of its galaxy—the first dormant black hole detected so far from a galactic core。 It revealed itself only after shredding a passing star and producing a brief, brilliant flare。 Astronomers think it may be the remnant of a devoured galaxy or a black hole flung o

A new hollow nanoreactor mimics living cells to make hydrogen peroxide more efficiently using visible light。 Its light-trapping cavity and proton-shuttling shell could open new possibilities for cleaner chemical manufacturing and artificial photosynthesis

The organization, Network for Hope, "strongly disagrees" with Trump admin's decision

NASA’s Swift Observatory observed a supermassive black hole ripping apart a star more than 30,000 light-years from the center of a distant galaxy。 The extraordinary flare briefly outshone its entire host galaxy in ultraviolet light and revealed a black hole about a million times the Sun’s mass

Scientists have identified LHAASO J1912+1014u as a cosmic accelerator that can push protons beyond one quadrillion electron volts。 The finding may help reveal where the Milky Way’s most energetic cosmic rays come from and how they influence the galaxy

Open source WeatherNext model can make accurate predictions with lower-resolution weather data

A court rules that a hold on all wind projects clearly violates the law

Clinicians and researchers say AI companies need to open up their safety data