We measure the frequency noise across a Cr:forsterite infrared frequency comb through the optical heterodyne beat of different comb teeth against stable continuous wave (CW) lasers. This sensitive measurement shows strong correlations of the frequency noise between spectral components of the comb, relative to a fixed optical frequency near the 1.3 micron carrier of the Cr:forsterite laser. The correlated frequency fluctuations are shown to arise from amplitude noise on the pump laser. We also report a preliminary comparison of excess noise that occurs during supercontinuum generation in both highly nonlinear fiber and an extruded glass microstructured fiber.
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http://dx.doi.org/10.1364/oe.15.017715 | DOI Listing |
Nano Converg
January 2025
Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup-si, Jeolabuk-do, 56212, Republic of Korea.
Metal-oxide thin-film semiconductors have been highlighted as next-generation space semiconductors owing to their excellent radiation hardness based on their dimensional advantages of very low thickness and insensitivity to crystal structure. However, thin-film transistors (TFTs) do not exhibit intrinsic radiation hardness owing to the chemical reactions at the interface exposed to ambient air. In this study, significantly enhanced radiation hardness of AlO-passivated ZnO TFTs against high-energy protons with energies of up to 100 MeV is obtained owing to the passivation layer blocking interactions with external reactants, thereby maintaining the chemical stability of the thin-film semiconductor.
View Article and Find Full Text PDFRev Sci Instrum
January 2025
Department of Plasma Physics and Fusion Engineering, University of Science and Technology of China, Hefei 230026, China.
A novel all-fiber optic current sensor (FOCS) is designed specifically for the measurement of large transient currents based on the Faraday effect. A reciprocal symmetric structure is incorporated into the optical sensing loop, and the current dependent phase demodulation is achieved by using a passive optical fiber coupler and the homodyne detection scheme. This design offers several advantages, including structural simplicity, high voltage insulation, low noise, high linearity, and excellent frequency response, and is highly suitable for use in any system of high-voltage, high-power, and high-frequency in nature.
View Article and Find Full Text PDFFront Neuroinform
January 2025
Centre Borelli, Université Paris Cité, UMR 9010, CNRS, Paris, France.
This article develops a fundamental insight into the behavior of neuronal membranes, focusing on their responses to stimuli measured with power spectra in the frequency domain. It explores the use of linear and nonlinear (quadratic sinusoidal analysis) approaches to characterize neuronal function. It further delves into the random theory of internal noise of biological neurons and the use of stochastic Markov models to investigate these fluctuations.
View Article and Find Full Text PDFInt J Audiol
January 2025
Department of Audiology, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran.
Objective: Tinnitus and its pathophysiological mechanisms need more investigation because tinnitus may change the typical processing of sounds in the auditory system. Poor temporal resolution, which is not assessed with conventional subjective tinnitus evaluations, has been reported in some tinnitus sufferers.
Design: This study used a gap-in-noise paradigm to assess temporal resolution in tinnitus sufferers using both behavioural and electrophysiologic methods.
Sci Rep
January 2025
College of Electrical and Information Engineering, Beihua University, Jilin, 132013, China.
Remote sensing images often suffer from the degradation effects of atmospheric haze, which can significantly impair the quality and utility of the acquired data. A novel dehazing method leveraging generative adversarial networks is proposed to address this challenge. It integrates a generator network, designed to enhance the clarity and detail of hazy images, with a discriminator network that distinguishes between dehazed and real clear images.
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