AI Article Synopsis
- Researchers are exploring distributed amplification methods in optical fiber sensors to enhance measurement range while mitigating fiber loss and nonlinear effects.
- Recent advancements show that using Raman amplification with specially designed intensity modulation can create a nearly lossless signal from one end of the fiber.
- The study combines this method with second order Raman pumping, achieving a detection range of 70 km, significantly improving sensitivity and reducing noise compared to standard techniques.
Article Abstract
In distributed optical fibre sensors, distributed amplification schemes have been investigated in order to increase the measurement range while avoiding the limitation imposed by the fibre attenuation and the nonlinear effects. Recently, the use of Raman amplification with an engineered intensity modulation has been demonstrated as an efficient way to produce a virtually lossless trace employing a single-end configuration. In this paper, we propose the combination of this technique with a simultaneous second order Raman pumping scheme for increasing the measurement range. The optimal modulation profile has been numerically analyzed and we experimentally demonstrate a sensor able to detect perturbations along 70 km of fibre, with a minimal SNR penalty along the total length. Thanks to this new approach, the sensitivity in the worst point is considerably improved, and the ASD noise floor is also reduced. The measurement range is extended approximately 15 km compared with the equivalent first order pumping case.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/OE.440514 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
[PLSR model based on near-infrared spectroscopy for the detection of wood fiber anatomy of ].
Ying Yong Sheng Tai Xue Bao
October 2024
Research Institute of Subtropical Forestry, Chinese Academy of Forestry/Zhejiang Key Laboratory of Forest Genetics and Bree-ding, Hangzhou 311400, China.
To rapidly acquire fiber phenotypic data for wood quality assessment, we used a portable NIR spectro-meter to collect spectral data in 100 individuals of at 18-year-old of 20 different provenances, and simultaneously collected wood cores. Wood basic density and the anatomical structure of wood fiber were measured. The standard normal variate (SNV), orthogonal signal correction (OSC), and multiplicative scatter correction (MSC) methods were used for spectral preprocessing, the competitive adaptive reweighted sampling (CARS) method were used for wavelength selection, and the partial least squares regression (PLSR) model were established.
View Article and Find Full Text PDF[Impacts of freeze-thaw process on soil microbial nutrient limitation in slope farmlands of the Chinese Mollisol region].
Ying Yong Sheng Tai Xue Bao
October 2024
State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, Shaanxi, China.
Understanding the impacts of freeze-thaw action on soil microbial nutrient limitation can provide important support for sustainable utilization of black soil resources. We analyzed the impacts of freeze-thaw action on soil microbial nutrient limitation on a slope farmland located in a typical thick Mollisol region of Keshan County, Heilongjiang Province. We examined the responses of soil microbial nutrient limitation to soil erosion rates through measuring soil nutrient, soil microbial biomass, and soil enzyme activities before and after freeze-thaw under natural conditions, and estimated the soil erosion rates by Cs tracing technology.
View Article and Find Full Text PDF[Changes of climate niche of during its invasion in China].
Ying Yong Sheng Tai Xue Bao
October 2024
Research Center for UAV Remote Sensing, College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China.
Niche conservatism is essential for predicting the risk of alien species invasions. Currently, the changes of climate niche of during its invasion in China are still not clear. Using principal component analysis, we examined the climate niche shifts of during its invasion and analyzed its potential distribution in China.
View Article and Find Full Text PDFPrevalence of Vitamin D Deficiency With Biochemical Abnormalities in Children Undergoing Vitamin D Testing.
Clin Endocrinol (Oxf)
December 2024
Department of Medicine, University of Auckland, Auckland, New Zealand.
Objective: Vitamin D deficiency (VDD) in children can cause hypocalcaemia and rickets, but the prevalence of these complications and the 25-hydroxyvitamin D (25OHD) concentrations below which they arise is uncertain. We investigated this in children (< 18 years) with 25OHD measurements.
Design, Measurement And Patients: We obtained 25OHD results from the regional laboratory database, alongside albumin-adjusted serum calcium (aCa), parathyroid hormone (PTH) and alkaline phosphatase (ALP) within 6 months of the index 25OHD.
A Prospective, Single-Cohort, Open, Multi-Center, Observational Study of Sublingual Fentanyl for Breakthrough Cancer Pain: Effectiveness, Safety, and Tolerability in Korean Cancer Patients.
Cancer Res Treat
December 2024
Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Purpose: Fentanyl, a highly lipophilic opioid, was developed as a sublingual fentanyl tablet (SFT) for the management of breakthrough cancer pain (BTcP), and its efficacy and safety were confirmed in a randomized, controlled study. We investigated the effectiveness and safety of SFT administered to alleviate BTcP in a real-world setting.
Materials And Methods: In this prospective, open, single-cohort study, conducted in 13 referral hospitals in South Korea, opioid-tolerant cancer patients receiving around-the-clock opioids for persistent cancer pain were enrolled if the individual had BTcP ≥ 1 episode/day during the preceding week.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!