scholarly journals A Novel Approach to Realizing Low-Cost Plasmonic Optical Fiber Sensors: Light-Diffusing Fibers Covered by Thin Metal Films

Fibers ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 34 ◽  
Author(s):  
Nunzio Cennamo ◽  
Luigi Zeni ◽  
Francesco Arcadio ◽  
Ester Catalano ◽  
Aldo Minardo
Keyword(s):  
Refractive Index ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
Experimental Tests ◽  
Optical Fiber Sensors ◽  
Metal Films ◽  
Refractive Indices ◽  
Signal To Noise ◽  
Fiber Sensors ◽  
Novel Approach

We have investigated, in a numerical and experimental way, a refractive index (RI) sensor based on surface plasmon resonance (SPR) in a silver-coated light-diffusing fiber (LDF). The experimental tests were conducted using water-glycerine mixtures with refractive indices ranging from 1.332 to 1.388. In the considered refractive index range, the experimental results show a sensitivity of the SPR wavelength to the outer medium’s RI ranging from 2600 to 4700 nm/RIU, which is larger than the sensitivity recently reported for a gold-coated LDF sensor (1200 to 4000nm/RIU). The silver-coated sensor is also shown to ensure a higher signal-to-noise ratio (SNR) compared to the gold-coated sensor.

Development of Low-Cost Abbe Refractometer

2018 ◽  
Vol 879 ◽  
pp. 227-233
Author(s):  
Weeratouch Pongruengkiat ◽  
Thitika Jungpanich ◽  
Kodchakorn Ittipornnuson ◽  
Suejit Pechprasarn ◽  
Naphat Albutt
Keyword(s):  
Refractive Index ◽  
Optical Materials ◽  
Low Cost ◽  
Optical Component ◽  
Refractive Indices ◽  
Constant Number ◽  
Optical Wavelength ◽  
Refractive Index Spectrum ◽  
Transparent Polymers ◽  
Abbe Refractometer

Refractive index and Abbe number are major physical properties of optical materials including glasses and transparent polymers. Refractive index is, in fact, not a constant number and is varied as a function of optical wavelength. The full refractive index spectrum can be obtained using a spectrometer. However, for optical component designers, three refractive indices at the wavelengths of 486.1 nm, 589.3 nm and 656.3 nm are usually sufficient for most of the design tasks, since the rest of the spectrum can be predicted by mathematical models and interpolation. In this paper, we propose a simple optical instrumental setup that determines the refractive indices at three wavelengths and the Abbe number of solid and liquid materials.

Fabrication of Optical Fiber Sensors Based on Femtosecond Laser Micro Machining

2020 ◽  
Vol 8 (4) ◽  
Author(s):  
Fengfeng Zhou ◽  
Seunghwan Jo ◽  
Xingyu Fu ◽  
Jung-Ting Tsai ◽  
Martin Byung-Guk Jun
Keyword(s):  
Refractive Index ◽  
Femtosecond Laser ◽  
Optical Fiber ◽  
Refractive Index Change ◽  
Optical Fiber Sensors ◽  
Objective Lens ◽  
Machining Parameters ◽  
Fiber Sensors ◽  
The Core ◽  
First Time

Abstract In this research, we proposed fabrication process of optical fiber sensors using femtosecond laser and their applications. A beam of femtosecond laser was focused by an objective lens in the optical fiber. By testing different conditions, a group of machining parameters was found that achieve a minimum machining resolution of 3.2 μm. To ablate the core of the optical fiber, which is buried deep inside the cladding, precisely, part of the cladding was removed to expose the core as close as possible to the air. By making a complex pattern to modify the optical path of the laser inside an optical fiber, a sensitivity of 942.8–1015.6 nm per refractive index unit (nm/RIU) was obtained for liquid refractive index sensing. For another sensor, a sensitivity of 1.38 × 105 nm/RIU was obtained, which is high enough to detect small amount of refractive index change of air. It is known to be the first time that we fabricated a complex microstructure in an optical fiber to modify the propagation of the light using femtosecond laser. This research shows the possibility of a complex modification of light in an optical fiber using laser machining.

Internally Modulated Chirped Pulse Based Direct Detection Type φ-OTDR System with High Signal-to-Noise Ratio and Low Cost

2019 ◽  
Vol 46 (8) ◽  
pp. 0806003
Author(s):  
李鲁川 Luchuan Li ◽  
卢斌 Bin Lu ◽  
王校 Xiao Wang ◽  
梁嘉靖 Jiajing Liang ◽  
郑汉荣 Hanrong Zheng ◽  
...  
Keyword(s):  
Direct Detection ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
High Signal ◽  
Signal To Noise ◽  
Chirped Pulse ◽  
Noise Ratio

scholarly journals Signal-to-noise optimization and evaluation of a home-made visible diode-array spectrophotometer

1993 ◽  
Vol 15 (6) ◽  
pp. 227-232 ◽  
Author(s):  
Ivo M. Raimundo, Jr. ◽  
Celio Pasquini
Keyword(s):  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
Optical Design ◽  
Signal To Noise ◽  
Noise Optimization ◽  
Instrument Control ◽  
Automatic Methods ◽  
Photodiode Array ◽  
Variable Integration

This paper describes a simple low-cost multichannel visible spectrophotometer built with an RL512G EGG-Reticon photodiode array. A symmetric Czerny-Turner optical design was employed; instrument control was via a single-board microcomputer based on the 8085 Intel microprocessor. Spectral intensity data are stored in the single-board's RAM and then transferred to an IBM-AT 3865X compatible microcomputer through a RS-232C interface. This external microcomputer processes the data to recover transmittance, absorbance or relative intensity of the spectra. The signal-to-noise ratio and dynamic range were improved by using variable integration times, which increase during the same scan; and by the use of either weighted or unweighted sliding average of consecutive diodes. The instrument is suitable for automatic methods requiring quasi-simultaneous multiwavelength detections, such as multivariative calibration and flow-injection gradient scan techniques.

Three-Dimensional Optical Bit Memory in Sm(DBM)3Phen-Doped and Un-Doped Poly(methyl methacrylate)

2011 ◽  
Vol 284-286 ◽  
pp. 2251-2254
Author(s):  
Zhao Gang Nie ◽  
Xin Zhong Li ◽  
Yu Ping Tai ◽  
Ki Soo Lim ◽  
Myeongkyu Lee
Keyword(s):  
Refractive Index ◽  
Methyl Methacrylate ◽  
Signal To Noise Ratio ◽  
Three Dimensional ◽  
Pulsed Laser ◽  
High Signal ◽  
Signal To Noise ◽  
Fluorescent Signal ◽  
Poly Methyl Methacrylate ◽  
Noise Ratio

The feasibility of three-dimensional optical bit memory is demonstrated by using the change of fluorescence and refractive index in Sm(DBM)3Phen-doped and un-doped Poly(methyl methacrylate). After a femtosecond pulsed laser irradiation, a refractive-index bit and a fluorescent bit can be formed at the same position inside the bulk sample. Multilayer patterns recorded by tightly focusing the pulsed laser beam were read out by a reflection-type fluorescent confocal microscope, which can detect the reflection signal and also the fluorescent signal of the stored bits. The signal-to-noise ratio via the two retrieval modes was compared as a function of recording depth. The stored bits were retrieved with a high signal-to-noise ratio in the absence of any crosstalk and the detection of the fluorescent signal enables retrieval of the stored bits with a higher S/N ratio.

A Motorized Microdrive for Recording of Neural Ensembles in Awake Behaving Rats

2005 ◽  
Vol 127 (6) ◽  
pp. 1035-1040 ◽  
Author(s):  
R. Venkateswaran ◽  
Chris Boldt ◽  
J. Parthasarathy ◽  
B. Ziaie ◽  
A. G. Erdman ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Low Cost ◽  
Dynamic Control ◽  
Experimental Paradigm ◽  
Signal To Noise ◽  
Implanted Electrodes ◽  
Neural Ensembles ◽  
Dc Motors ◽  
Cell Electrode ◽  
Scientific Advances

The recording of neural ensembles in awake, behaving rats has been an extremely successful experimental paradigm, providing demonstrable scientific advances. Dynamic control of the position of the implanted electrodes is of key importance as mobile electrodes provide a better signal-to-noise ratio and a better cell/electrode yield than nonmobile electrodes. Here we describe the use of low cost, soon to be commercially available dc motors to successfully control the depth of electrodes. The prototype designed is approximately 30mm in diameter and 50mm in length and weighed about 30gms. This paper presents the results of linear displacements of electrodes achievable with this motorized microdrive.

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