scholarly journals Effect of Temperature and Germania on the Performance of Germania Doped Silica Fiber Raman Scattering Amplifier

2022 ◽  
Author(s):  
B. M. El-den ◽  
Adel zaghloul
Keyword(s):  
Pump Power ◽  
Gain Coefficient ◽  
Effect Of Temperature ◽  
Refractive Indices ◽  
Raman Gain ◽  
Gain Saturation ◽  
Core Radius ◽  
Signal Wavelength ◽  
Amplifier Gain ◽  
Better Than

Abstract The Raman gain coefficient, the attenuations at signal and pump wavelengths and the refractive indices of both core and cladding of silica doped Germania optical fiber are functions of the Germania ratio, temperature and wavelengths. The Raman amplifier gain increases with Germania ratio but it decreases with temperature. Also, Raman gain either increases or decreases with signal wavelength. As the fiber core radius increases, the Raman gain decreases. The gain distribution through the amplifier length of dual pumps with power divided ratio (S=0.5) is better than that for the forward pump amplifier and the backward pump amplifier. The forward pump has a maximized gain but the backward pump has a minimized gain, while the dual pumps have both the maximum and minimized gains. The final amplifier gain for the three kinds of pumps with the same pump power (Pp) is equally.The pump wavelength (λp=1.4553μm) gives the biggest Raman gain at the center of wideband signal wavelength (λs=1.50 to 1.60μm). With λp =1.48μm, the gain increases with λs until λs=1.57μm and after that the gain decreases with λs and so with the above three kinds of pumps, gain fluctuations over the band wavelength of signal. The threshold pump power and gain saturation are studied.

Simulation for enhancement in sensitivity of chalcogenide glasses-based fibre optic evanescent absorption sensor for malignant tissue detection

2020 ◽  
Vol 12 ◽  
Author(s):  
Ritesh Kumar Singh ◽  
Adarsh Chandra Mishra ◽  
Pooja Lohia ◽  
D.K. Dwivedi
Keyword(s):  
Evanescent Wave ◽  
Chalcogenide Glasses ◽  
Biological Tissues ◽  
Biological Species ◽  
Primary Objective ◽  
Effect Of Temperature ◽  
Refractive Indices ◽  
Core Radius ◽  
Source Illumination ◽  
Study Results

Background: Refractive index determination of biological tissues is a challenging issue. Many biological species also show vibrational signature in infrared domain. The chalcogenide-based glasses can be used to make the fiber optic evanescent wave sensors for detection of analyte. Objectives: The primary objective is to study the effect of various parameters on the sensitivity of chalcogenide glass-based evanescent wave sensor for biological tissue detection. Methods: An evanescent wave sensor has been proposed with collimated source illumination and uniform tapering. The chalcogenide materials are chosen such that the weakly guiding approximation could be followed. Complex refractive indices of liver tissue samples have been taken for the analysis of sensitivity via method of evanescent absorption coefficient. Equations for sensitivity have been solved analytically using MATLAB software. Results: The simplification of the formula for sensitivity leads to the inference that the sensitivity is a function of core radius, refractive indices of sample tissues and wavelength used. Moreover, since the refractive indices of the materials are also a function of temperature, therefore a change in temperature results into change in the profile of guiding mode. Hence the effect of temperature must also be observed. The initial simulation parameters are taken; core radius 100 µm, sensing length 4 cm and wavelength 1.0 µm. In the NIR region we have a better sensitivity of detection for all the tissues samples and the risk of photodamage of the biosamples is reduced to a good extent. It has been found that sensitivity decreases with wavelength and core radius whereas increases with temperature. It has also been shown that sensitivity is found to be better with collimated in comparison with diffused source. Conclusion: The comparative study results that one should operate at shorter NIR region of wavelength for higher sensitivity. The collimated source illumination should be preferred over diffused one for launching the light within the fiber to have high sensitivity. Further, length of sensing region should be larger but the fiber core radius should be smaller. The proposed biosensor is robust and can also be used many times if the probe (sensing region) is cleaned properly. Moreover, a small amount of analyte is enough for the detection. Thus, the proposed sensor is very useful for bio-medical applications with its high performance, accuracy and robustness.

scholarly journals Effect of Temperature and Pyrolysis Time in Liquid Smoke Production from Dried Water Hyacinth

2020 ◽  
Vol 9 (1) ◽  
pp. 164-171
Keyword(s):  
Refractive Index ◽  
Water Hyacinth ◽  
Effect Of Temperature ◽  
Refractive Indices ◽  
Total Acid ◽  
Temperature Variations ◽  
Liquid Smoke ◽  
Time Variations ◽  
Pyrolysis Reactor ◽  
Time Variables

This study aimed to investigate the use of water hyacinth to produce liquid smoke. The study observes the temperature and time variables of yield, pH, density, and refractive index in the production of liquid smoke from water hyacinth. The sequence of the work is as follows: first, water hyacinth was cut into 5 cm sections and then sun-dried for 2–3 d, depending on the weather. Next, 550 g of dried water hyacinth was added to the pyrolysis reactor. The temperature variations were 200°C, 400°C, and 600°C, and the time variations were 1, 4, and 7 h. As a result, liquid smoke was produced with varying yield, pH, densities, and refractive indices. The best results in this research are liquid smoke pyrolysis at a temperature of 400°C and 4 h with the acquisition of a yield of 93 mL, pH 2–4, a density of 1.080,8 gr/mL, and a refractive index of 1.339,6, with chemical component 41.45% total acid, 2.44% phenol and 56.10% carbonyl.

scholarly journals Effect of temperature and mating pair on tribological properties of DLC and GLC coatings under high pressure lubricated by MoDTC and ZDDP

Friction ◽  
2020 ◽  
Author(s):  
Kang Liu ◽  
Jia-jie Kang ◽  
Guang-an Zhang ◽  
Zhi-bin Lu ◽  
Wen Yue
Keyword(s):  
Tribological Properties ◽  
Friction And Wear ◽  
Effect Of Temperature ◽  
Wear Properties ◽  
Dlc Coatings ◽  
Base Oil ◽  
Two Temperatures ◽  
Friction And Wear Properties ◽  
Lubrication Conditions ◽  
Better Than

AbstractDiamond-like carbon (DLC) and graphite-like carbon (GLC) coatings have good prospects for improving the surface properties of engine parts. However, further understanding is needed on the effect of working conditions on tribological behaviors. In this study, GLC and two types of DLC coatings were deposited on GCr15 substrate for investigation. The friction and wear properties of self-mated and steel-mated pairs were evaluated. Two temperatures (25 and 90 °C), three lubrication conditions (base oil, molybdenum dithiocarbamate (MoDTC)-containing oil, MoDTC+zinc dialkyldithiophosphate (ZDDP)-containing oil), and high Hertz contact stress (2.41 GPa) were applied in the experiments. The results showed that high temperature promoted the effect of ZDDP on steel-mated pairs, but increased wear under base oil lubrication. The increased wear for steel-mated pairs lubricated by MoDTC-containing oil was due to abrasive wear probably caused by MoO3 and β-FeMoO4. It was also found that in most cases, the tribological properties of self-mated pairs were better than those of steel-mated pairs.

scholarly journals Scaling of the raman gain coefficient: applications to germanosilicate fibers

2003 ◽  
Vol 21 (7) ◽  
pp. 1652-1662 ◽  
Author(s):  
K. Rottwitt ◽  
J. Bromage ◽  
A.J. Stentz ◽  
Lufeng Leng ◽  
M.E. Lines ◽  
...  
Keyword(s):  
Gain Coefficient ◽  
Raman Gain
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