We demonstrate a method to measure and actively reduce the coupling of vibrations to the phase noise of a cavity-stabilized laser. This method uses the vibration noise of the laboratory environment rather than active drive to perturb the optical cavity. The laser phase noise is measured via a beat note with a second unperturbed ultra-stable laser while the vibrations are measured by accelerometers positioned around the cavity. A Wiener filter algorithm extracts the frequency and direction dependence of the cavity response function. Once the cavity response function is known, real-time noise cancellation can be implemented by use of the accelerometer measurements to predict and then cancel the laser phase fluctuations. We present real-time noise cancellation that results in a 25 dB reduction of the laser phase noise power spectral density.
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http://dx.doi.org/10.1364/OE.18.018744 | DOI Listing |
J Neural Eng
January 2025
School of Biomedical Engineering, Southern Medical University, 1023 Shatai Road, Baiyun District, Guangzhou, Guangdong, 510515, CHINA.
Objective: Entrainment has been considered as a potential mechanism underlying the facilitatory effect of rhythmic neural stimulation on neurorehabilitation. The inconsistent effects of brain stimulation on neurorehabilitation found in the literature may be caused by the variability in neural entrainment. To dissect the underlying mechanisms and optimize brain stimulation for improved effectiveness, it is critical to reliably assess the occurrence and the strength of neural entrainment.
View Article and Find Full Text PDFiScience
January 2025
Department of Electrical and Computering Engineering, Binghamton University, Binghamton, NY 13902, USA.
Our recent research on type-I quadrature parity-time (PT) symmetry, utilizing an open twin-beam system, not only enables observing genuine quantum photonic PT symmetry amid phase-sensitive amplification (PSA) and loss in the presence of Langevin noise but also reveals an additional classical-to-quantum (C2Q) transition in noise fluctuations. In contrast to the previous setup, our exploration of an alternative system assuming no loss involves a type-II PSA-only scheme. This scheme facilitates dual opposing quadrature-PT symmetry, offering a comprehensive and complementary comprehension of C2Q transitions and PT-enhanced quantum sensing with optimal performance in the symmetry unbroken region.
View Article and Find Full Text PDFFront Neurorobot
January 2025
School of Business, Lingnan University, Hong Kong, China.
With the rapid development of tourism, the concentration of visitor flows poses significant challenges for public safety management, especially in low-light and highly occluded environments, where existing pedestrian detection technologies often struggle to achieve satisfactory accuracy. Although infrared images perform well under low-light conditions, they lack color and detail, making them susceptible to background noise interference, particularly in complex outdoor environments where the similarity between heat sources and pedestrian features further reduces detection accuracy. To address these issues, this paper proposes the FusionU10 model, which combines information from both infrared and visible light images.
View Article and Find Full Text PDFAnal Chem
January 2025
Shanghai Key Laboratory of Functional Materials Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Meilong Road, Shanghai 200237, P. R. China.
Protein methylation has attracted increasing attention due to its significant regulatory roles in various biological processes. However, the diversity of methylation forms, subtle differences between methylated and nonmodified sites, and their ultralow abundances pose substantial challenges for capturing and isolating methylated peptides from biological samples. Herein, we develop a chromatographic method that utilizes 4-sulfonylcalix[4]arene (SC4A) as a mobile phase additive and Click-Maltose as the stationary phase to separate methylated/nonmethylated peptides through the adsorption of the SC4A-(Me3) complex.
View Article and Find Full Text PDFSci Rep
January 2025
Faculty of Engineering, Université de Moncton, Moncton, NB, E1A3E9, Canada.
Diabetes is a growing health concern in developing countries, causing considerable mortality rates. While machine learning (ML) approaches have been widely used to improve early detection and treatment, several studies have shown low classification accuracies due to overfitting, underfitting, and data noise. This research employs parallel and sequential ensemble ML approaches paired with feature selection techniques to boost classification accuracy.
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