scholarly journals Simultaneous Measurement of Refractive Index and Flow Rate Using a Co2+-Doped Microfiber

2021 ◽  
Vol 11 (22) ◽  
pp. 10525
Author(s):  
Da Liu ◽  
Ran Gao ◽  
Zhipei Li ◽  
Anle Qi
Keyword(s):  
Refractive Index ◽  
Flow Rate ◽  
Core Mode ◽  
Measurement Sensitivity ◽  
Resonant Modes ◽  
Cladding Mode ◽  
Bragg Grating Sensor ◽  
Maximum Measurement ◽  
Index Unit ◽  
Surrounding Liquid

This paper has proposed and experimentally demonstrated an integrated Co2+-doped microfiber Bragg grating sensor (Co-MFBGS) that can measure the surrounding liquid refractive index (LRI) and liquid flow rate (LFR) simultaneously. The Co-MFBGS provides well-defined resonant modes of core and cladding in the reflection spectrum. By monitoring the wavelength of the cladding mode, the LRI can be measured; meanwhile, by monitoring the wavelength of the core mode caused by the heat exchange, the LFR can be measured. The LRI and LFR can be distinguished by the wavelength separation between cladding mode and core mode. The experimental results show that in aqueous glycerin solution, the maximum measurement sensitivity for LRI detection is −7.85 nm/RIU (refractive index unit), and the LFR sensitivity is −1.93 nm/(μL/s) at a flow rate of 0.21 μL/s.

In-Fiber Mach-Zehnder Interferometer Fabricated by Femtosecond Laser

2013 ◽  
Vol 658 ◽  
pp. 232-236
Author(s):  
Zhi Long Ou ◽  
Yong Qin Yu ◽  
Jia Rong Zheng ◽  
Ji Shun Wang ◽  
Xue Chen ◽  
...  
Keyword(s):  
Refractive Index ◽  
Femtosecond Laser ◽  
Repetition Rate ◽  
Laser Pulses ◽  
Resonance Wavelength ◽  
Femtosecond Laser Pulses ◽  
Experimental Results ◽  
Spatial Period ◽  
Core Mode ◽  
Cladding Mode

We have demonstrated several MZIs based on two spaced 3-dB LPFGs with different interference lengths in conventional SMFs fabricated in air by femtosecond laser pulses with the duration of 200 fs and the repetition rate of 250 kHz. Experimental results show that the average fringe spatial period increases with the resonance wavelength, while decreases with the interference length in approximately inverse proportion. The dominant cladding mode interfering with core mode has been calculated. The MZI sensitivity on temperature, refractive index and strain with a length of 16mm has also been investigated.

scholarly journals Hybrid Grating in Reduced-Diameter Fiber for Temperature-Calibrated High-Sensitivity Refractive Index Sensing

2019 ◽  
Vol 9 (9) ◽  
pp. 1923
Author(s):  
Biqiang Jiang ◽  
Zhen Hao ◽  
Dingyi Feng ◽  
Kaiming Zhou ◽  
Lin Zhang ◽  
...  
Keyword(s):  
Refractive Index ◽  
Simultaneous Measurement ◽  
Surrounding Medium ◽  
High Sensitivity ◽  
Fiber Grating ◽  
Bragg Resonance ◽  
Core Mode ◽  
Promising Alternative ◽  
Sensing Applications ◽  
Highly Sensitive

We propose and experimentally demonstrate a hybrid grating, in which an excessively tilted fiber grating (Ex-TFG) and a fiber Bragg grating (FBG) were co-inscribed in a reduced-diameter fiber (RDF). The hybrid grating showed strong resonances due to coupling among core mode and a set of polarization-dependent cladding modes. This coupling showed enhanced evanescent fields by the reduced cladding size, thus allowing stronger interaction with the surrounding medium. Moreover, the FBG’s Bragg resonance confined by the thick cladding was exempt from the change of the surrounding medium’s refractive index (RI), and then the FBG can work as a temperature compensator. As a result, the Ex-TFG in RDF promised a highly sensitive RI measurement, with a sensitivity up to ~1224 nm/RIU near the RI of 1.38. Through simultaneous measurement of temperature and RI, the temperature dependence of water’s RI is then determined. Therefore, the proposed hybrid grating with a spectrum of multi-peaks embedded with a sharp Bragg resonance is a promising alternative for the simultaneous measurement of multi-parameters for many RI-based sensing applications.

Thermo-Fluid Design Simulation of Nd3+ POCl3 Transverse Flow Liquid Laser Cavity

2021 ◽  
pp. 1-31
Author(s):  
Vinod Singh ◽  
Gaurav Singhal ◽  
Prabal Talukdar
Keyword(s):  
Refractive Index ◽  
Temperature Gradient ◽  
Flow Rate ◽  
Optical Pumping ◽  
Gain Medium ◽  
Optical Path Difference ◽  
Path Difference ◽  
Transverse Flow ◽  
Optical Path ◽  
Liquid Laser

Abstract CFD based thermal design of a transverse flow optical cavity is carried out for 1 kW Nd3+ POCl3 liquid laser source to investigate temperature and velocity distribution in the optical pumping region of the cavity. Temperature gradient and turbulence both affect the refractive index of the liquid gain medium, which results in optical path difference, divergence and hence, poorer quality of the laser beam. The main purpose of this design is to achieve uniform flow and least temperature gradient in the optical pumping region so that the optical path difference can be minimized and a good beam quality can be achieved. CFD model has been developed for carrying out thermo-fluid simulations for this thermal system and based on these simulations, an optimum geometry of inlet ports along with their position from optical pumping region have been proposed. A user defined function (UDF) is incorporated for the input of spatially varying heat source term in each cell of the optical pumping region of the cavity. Variations in refractive index and optical path difference are estimated from the temperature data using another UDF. Simulation reveals that mass flow rate between 1.5 kg/s to 2.0 kg/s maintains the optical homogeneity of gain medium. Preliminary experiments have been carried out to demonstrate the effect of flow rate on the beam divergence and thereby exhibiting the importance of present simulation work.

scholarly journals NILAI TAMBAH MINYAK AKAR WANGI DENGAN PEMEKATAN KADAR VETIVEROL MENGGUNAKAN EKSTRAKSI CO2 FLUIDA SUPERKRITIK

2014 ◽  
Vol 16 (2) ◽  
pp. 76-81 ◽  
Author(s):  
Anny Sulaswatty ◽  
Egi Agustian
Keyword(s):  
Carbon Dioxide ◽  
Refractive Index ◽  
Specific Gravity ◽  
Supercritical Fluid Extraction ◽  
Supercritical Fluid ◽  
Flow Rate ◽  
Optical Rotation ◽  
Process Conditions ◽  
Fluid Extraction ◽  
Great Opportunity

Potensi Indonesia akan minyak akar wangi yang berorientasi ekspor dalam industri kosmetik, parfum, sabun, keperluan terapi, antiseptik, massage oil, farmasi dan pestisida memberikan peluang yang besar untuk memenuhi kebutuhan dunia. Guna nilai tambah minyak akar wangi dengan meningkatkan kadar vetiverol sebagai komponen utama, diaplikasikan teknologi ekstraksi fluida karbondioksida superkritik yang merupakan perpaduan ekstraksi, fraksinasi dan deodorisasi dengan didukung keunggulan karbondioksida sebagai pelarut yang inert, ramah lingkungan, mudah dipisahkan, dan berdaya larut tinggi.  Minyak akar wangi Garut (Java vetiver oil) sebagai bahan baku, mempunyai karakteristik  kadar vetiverol  39.03 %; Bobot jenis 0.9977; indeks bias 1.5247;  putaran optik +38.1; kelarutan dalam alkohol 95%  yaitu 1:1 jernih; bilangan asam 28.1; bilangan ester 24.6; bilangan ester setelah asetilasi 115.5; serta tidak mengandung minyak lemak dan  minyak keruing. Pemilihan kondisi proses guna menghasilkan kandungan vetiverol optimal dilakukan dengan memvariasikan laju alir gas CO2, tekanan dan suhu sebagai parameter penting dalam keberhasilan proses ekstraksi minyak akar wangi dengan fluida CO2 superkritik. Pemilihan laju alir konstan dan lebih stabil  diperoleh pada 5.5 liter/menit, sedangkan untuk variasi tekanan ekstraktor (1500, 1750, 2000 psi) dan suhu ekstraktor (40-50oC);  tekanan dan suhu separator  500 psi dan 25oC serta waktu proses selama lima jam dengan pengambilan ekstrak setiap jam. Tekanan dan suhu proses yang optimal diperoleh pada 1750 psi dan suhu 40oC  dengan  rafinat minyak akar wangi berkadar vetiverol  51.82 %,  bilangan ester 7.2 dan bilangan ester setelah asetilasi  172.4. Tingginya tekanan dan rendahnya suhu berpengaruh terhadap perolehan ekstrak; penurunan rafinat; peningkatan nilai  bobot jenis ekstrak dan rafinat; indeks bias ekstrak dan rafinat; putaran optik ekstrak dan rafinat; peningkatan viskositas ekstrak dan rafinat; peningkatan bilangan ester ekstrak, bilangan ester setelah asetilasi ekstrak, serta kandungan vetiverol.Kata Kunci: Minyak Akar Wangi, Vetiverol, Ekstraksi Fluida Superkritik Potential Indonesian vetiver oil export oriented industry of cosmetics, perfumes, soaps, therapeutic purposes, antiseptic, massage oil, pharmaceutical and pesticide presents a great opportunity to meet the needs of the world. In order to add value vetiver oil by increasing the levels vetiverol as the main component, was applied to carbon dioxide supercritical fluid extraction technology which is a combination of extraction, fractionation and deodorization with excellence supported carbon dioxide as an inert solvent, eco-friendly, easily separated, and the high solubility. Garut vetiver oil (Java vetiver oil) as raw material, has the characteristics vetiverol levels 39.03%, specific gravity of 0.9977; refractive index of 1.5247; optical rotation +38.1; solubility in alcohol 95% is a clear 1:1; acid number 28.1; ester number 24.6; ester number after acetylation 115.5; as well as fats and oils contain no oil keruing. The selection process conditions in order to produce optimal vetiverol content performed by varying the flow rate of CO2 gas, pressure and temperature as an important parameter in the success of vetiver oil extraction with supercritical CO2 fluid. The selection of a constant flow rate and more stable obtained at 5.5 liters / min, whereas for pressure variation extractor (1500-2000 psi) and extractor temperature (40-50oC); separator pressure and temperature of 500 psi and 25 °C as well as the processing time for five hours by taking extracts every hour. Pressure and temperature optimum process obtained at 1750 psi and a temperature of 40oC with rafinat vetiverol vetiver oil yield of 51.82%, ester number 7.2, and ester number after acetylation 172.4. The high pressure and low temperature affect the acquisition of the extract; rafinat decline; increase in the value of specific gravity and rafinat extracts; refractive index and rafinat extract; optical rotation and rafinat extract; increase in the viscosity of the extract and rafinat; increase in numbers ester extract, ester number after acetylation extracts, as well as the content vetiverol. Key word: Vetiver Oil, Vetiverol, Supercritical Fluid Extraction.

Refractive index and temperature sensor based on cladding-mode Bragg grating excited by abrupt taper interferometer

2013 ◽  
Vol 11 (12) ◽  
pp. 120604-120607 ◽  
Author(s):  
Shen Yang Shen Yang ◽  
Hao Sun Hao Sun ◽  
Liutong Yuan Liutong Yuan ◽  
Xiaolei Zhang Xiaolei Zhang ◽  
Libin Zhou Libin Zhou ◽  
...  
Keyword(s):  
Refractive Index ◽  
Temperature Sensor ◽  
Bragg Grating ◽  
Cladding Mode

scholarly journals Relationship between Oxygen Defects and Properties of Scandium Oxide Films Prepared by Ion-Beam Sputtering

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 517
Author(s):  
Pengfei Kong ◽  
Yunti Pu ◽  
Ping Ma ◽  
Jiliang Zhu
Keyword(s):  
Refractive Index ◽  
Surface Quality ◽  
Flow Rate ◽  
Ion Beam ◽  
Oxygen Flow Rate ◽  
Scandium Oxide ◽  
Oxygen Flow ◽  
Ion Beam Sputtering ◽  
Oxygen Defects ◽  
Beam Sputtering

Scandium oxide (Sc2O3) thin films with different numbers of oxygen defects were prepared by ion-beam sputtering under different oxygen flow rates. The results showed that the oxygen defects heavily affected crystal phases, optical properties, laser-induced damage threshold (LIDT) and surface quality of Sc2O3 films. The thin film under 0 standard-state cubic centimeter per minute (sccm) oxygen flow rate had the largest number of oxygen defects, which resulted in the lowest transmittance, LIDT and the worst surface quality. In addition, the refractive index of 0 sccm Sc2O3 film could not be measured in the same way. When the oxygen flow rate was 15 sccm, the Sc2O3 film possessed the best transmittance, refractive index, LIDT and surface roughness due to the lowest number of oxygen defects. This work elucidated the relationship between oxygen defects and properties of Sc2O3 films. Controlling oxygen flow rate was an important step of limiting the number of oxygen defects, which is of great significance for industrial production.

scholarly journals Temperature-Insensitive Refractive Index Sensor with Etched Microstructure Fiber

Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3749 ◽  
Author(s):  
Bin Dai ◽  
Xiang Shen ◽  
Xiongwei Hu ◽  
Luyun Yang ◽  
Haiqing Li ◽  
...  
Keyword(s):  
Refractive Index ◽  
Low Temperature ◽  
Extinction Ratio ◽  
Refractive Index Sensor ◽  
Large Mode Area ◽  
Pure Silica ◽  
Microstructure Fiber ◽  
Cladding Mode ◽  
Mode Area ◽  
Sensing Characteristics

A Mach–Zehnder interferometer (MZI) based on an etched all-solid microstructure fiber (MOF) has been demonstrated. The MZI works on the basis of interference between the vibrant core and cladding modes in the MOF. The all-solid MOF has a heterostructure cladding composed of Ge-doped rod arrays and pure silica, and thus can support and propagate a vibrant cladding mode with a large mode area. When the outermost cladding of MOF is etched, the cladding mode becomes sensitive to the ambient refractive index (RI). The etched MOF can work as a sensing head for RI sensing. By comparing the interference spectra, the extinction ratio has remained stable at around 20 dB after the MOF was etched. The RI sensing characteristics of the MZI with an etched MOF have also been investigated. The results show that the RI sensitivity can reach up to 2183.6 nm/RIU with a low-temperature coefficient (<10 pm/°C).

scholarly journals Etched Fiber Bragg Grating Biosensor Functionalized with Aptamers for Detection of Thrombin

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4298 ◽  
Author(s):  
Aliya Bekmurzayeva ◽  
Kanat Dukenbayev ◽  
Madina Shaimerdenova ◽  
Ildar Bekniyazov ◽  
Takhmina Ayupova ◽  
...  
Keyword(s):  
Refractive Index ◽  
Fiber Bragg Grating ◽  
Chemical Vapor ◽  
Bragg Grating ◽  
Clinical Settings ◽  
Long Period Grating ◽  
Bragg Wavelength ◽  
Sensing System ◽  
Index Unit

A biosensor based on an etched Fiber Bragg Grating (EFBG) for thrombin detection is reported. The sensing system is based on a Fiber Bragg Grating (FBG) with a Bragg wavelength of 1550 nm, wet-etched in hydrofluoric acid (HF) for ~27 min, to achieve sensitivity to a refractive index (RI) of 17.4 nm/RIU (refractive index unit). Subsequently, in order to perform a selective detection of thrombin, the EFBG has been functionalized with silane-coupling agent 3-(aminopropyl)triethoxysilane (APTES) and a cross-linker, glutaraldehyde, for the immobilization of thrombin-binding aptamer. The biosensor has been validated for thrombin detection in concentrations ranging from 10 nM to 80 nM. The proposed sensor presents advantages with respect to other sensor configurations, based on plasmonic resonant tilted FBG or Long Period Grating (LPG), for thrombin detection. Firstly, fabricating an EFBG only requires chemical etching. Moreover, the functionalization method used in this study (silanization) allows the avoidance of complicated and expensive fabrications, such as thin film sputtering or chemical vapor deposition. Due to their characteristics, EFBG sensors are easier to multiplex and can be used in vivo. This opens new possibilities for the detection of thrombin in clinical settings.

Research on the Vortex Mass Flow Meter of Dual Bluff Body Based on Differential Pressure Principle

2013 ◽  
Vol 401-403 ◽  
pp. 1110-1113
Author(s):  
Quan Sheng Duan ◽  
Li Cui Wang
Keyword(s):  
Lower Limit ◽  
Mass Flow ◽  
Flow Rate ◽  
Bluff Body ◽  
Differential Pressure ◽  
Low Flow ◽  
Body Structure ◽  
Measurement Sensitivity ◽  
Flow Meter ◽  
Pressure Signal

The lower limit of the existing vortex mass flow meter based on differential pressure is high. So the application of the existing vortex mass flow meter is limited in the measurement for low flow rate. This paper proposes a method using vortex mass flow meter of dual bluff body based on differential pressure principle. The differential pressure signal between the upstream and downstream can be amplified by the vortex overlap caused by the dual bluff body structure. The results of the simulation by Fluent show that this method can reduce the lower limit of measurement, and improve the measurement sensitivity effectively.

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