Rayleigh scattering generates intensity noise close to an optical carrier that propagates in a single-mode optical fiber. This noise degrades the performance of optoelectronic oscillators and RF-photonic links. When using a broad linewidth laser, we previously found that the intensity noise power scales linearly with optical power and fiber length, which is consistent with guided entropy mode Rayleigh scattering (GEMRS), a third order nonlinear scattering process, in the spontaneous limit. In this work, we show that this behavior changes significantly with the use of a narrow linewidth laser. Using a narrow linewidth laser, we measured the bandwidth of the intensity noise plateau to be 10 kHz. We found that the scattered noise power scales superlinearly with fiber length up to lengths of 10 km in the frequency range of 500 Hz to 10 kHz, while it scales linearly in the frequency range of 10 Hz to 100 Hz. These results suggest that the Rayleigh-scattering-induced intensity noise cannot be explained by third-order nonlinear scattering in the spontaneous limit, as previously hypothesized.
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http://dx.doi.org/10.1364/OE.23.006400 | DOI Listing |
Anal Biochem
January 2025
Key Laboratory of Green and Precise Synthetic Chemistry and Applications, Ministry of Education, Anhui Provincial Key Laboratory of Synthetic Chemistry and Applications, College of Chemistry and Materials Science, Huaibei Normal University, Huaibei, Anhui 235000, PR China. Electronic address:
Luminol-loaded mesoporous carbon nanospheres (MCs@LU) were utilized to develop a highly sensitive electrochemiluminescence (ECL) sensor for the detection of L-cysteine (L-Cys). L-Cys acted as the coreactant of luminol, and the pore confinement effect of mesoporous carbons (MCs) resulted in a robust ECL signal. Upon optimization, a linear correlation between the ECL intensity and L-Cys concentration was observed over the range of 5.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Department of Physics, Durham University, South Road, Durham DH1 3LE, United Kingdom.
PLoS One
January 2025
Department of Computer Science, National Textile University, Faisalabad, Pakistan.
Accurate diagnosis of pancreatic cancer using CT scan images is critical for early detection and treatment, potentially saving numerous lives globally. Manual identification of pancreatic tumors by radiologists is challenging and time-consuming due to the complex nature of CT scan images and variations in tumor shape, size, and location of the pancreatic tumor also make it challenging to detect and classify different types of tumors. Thus, to address this challenge we proposed a four-stage framework of computer-aided diagnosis systems.
View Article and Find Full Text PDFAnalyst
January 2025
Questrom School of Business, Boston University, Boston, MA, 02215, USA.
Latent fingerprints (LFPs) are invisible impressions that need to be developed before being used for criminal investigation; however, existing fingerprint visualization techniques face challenges, such as complex preparation and poor contrast. To advance practical fingerprint detection, green-emissive micron-sized curcumin/kaolin composites were synthesized a facile and cost-effective one-step physical cross-linking method, which exhibited unprecedented performance in developing diversified marks, including LFPs, knuckle prints, palm prints, and footprints, with clear three-level details on various substrates. Notably, the powders successfully developed LFPs that were aged for 30 days and even up to 100 days, meeting the stringent requirements for comprehensive forensic application.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Neurobehavioral Systems, Inc, Berkeley, CA, USA.
Background: The administration of cognitive tests in patients' homes facilitates access by underserved communities and increases testing capacity and efficiency. However, the validity of at-home computerized cognitive tests is often questioned because of limitations in examiner monitoring, distractions, environmental noise, and potential cheating. Here, we compare performance of the computerized and proctored California Cognitive Assessment Battery (CCAB) when administered at-home or in the laboratory using otherwise identical procedures.
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