Distributed fluorescent optical fiber proximity sensor: Towards a proof of concept

Fluorescent fibers are optical fibers which emit light as a response to an incident phenomenon, usually an incident light. Operation depends on the doping dyes, which determine specific fluorescence and optical characteristics useful in the development of optical sensors. In this work we propose a low-cost distributed proximity sensor implemented using a red fluorescent fiber, to provide a security option for a surface plasmon resonance system. Operation of the proposed sensor relies on having the incident illumination intensity varied by the presence or absence of an obstacle in the vicinity of the sensing element. This will influence the radiated fluorescence accordingly. The proposed setup for the implementation of the optical proximity sensor assumes having a high brightness LED deployed for axial fiber illumination and a blue LED for side illumination. Electronic processing then accounts for gain and digitization. Measurement results of the prototype validate the proposed concept

The Prowler IADS performance evaluation tool (PIPE)

The Prowler IADS Performance Evaluator is a computer simulation model of an airstrike protected by electronic countermeasures platforms. It is designed for integration into mission planning systems and analysis tools used to determine the effectiveness of electronic countermeasures or allocate scarce countermeasures equipment. PIPE's features include flexible hierarchical IADS specification, the capability to construct and calculate appropriate measures of performance, graphical presentation analysis results, mission visualizationNaval Postgraduate School, Monterey, California.http://archive.org/details/prowleriadsperfo00bailMonterey, California. Naval Postgraduate SchoolApproved for public release; distribution is unlimited

The method for UGR index measurement with use of a camera with CCD matrix

W artykule przedstawiono ideę oraz praktyczną realizację czujnika wybranych parametrów cieczy przepływającej przez dwuwarstwowy światłowód kapilarny, określanych na podstawie pomiaru współczynnika załamania światła tej cieczy. Zaprezentowano analizę działania sensora zrealizowaną z wykorzystaniem metody elementarnych strumieni świetlnych. Jako przykład zastosowania zaprojektowanego i wykonanego czujnika, przedstawiono czujnik temperatury oleju pracujący w zakresie 10-70 °C. Zmiana temperatury w badanym zakresie implikuje zmianę współczynnika załamania światła oleju w granicach 1,370-1,385. Przedstawiono konstrukcję i charakterystyki wytworzonego czujnika. Głównymi zaletami tego rozwiązania są: szybkość wykonywania pomiarów, zapewnienie izolacji galwanicznej z mierzoną cieczą oraz możliwość ciągłego monitorowania cieczy przepływającej przez światłowód kapilarny. Jest to istotne w wielu zastosowaniach w automatyce i w systemach kontroli procesów przemysłowych, gdzie zaprezentowany czujnik może znaleźć zastosowanie.The paper presents an idea and practical realization of a sensor for determination of selected properties (e.g. temperature or concentration of solution etc.) of liquid flowing through double layer capillary waveguide based on measurements of the refractive index of this liquid. The transfer of a luminous flux through the capillary waveguide was performed by numerical analysis using the ray propagation method. The simulation showed that the response signal from the capillary sensor depends strongly on the liquid refractive index. For the liquid refractive index changes from 1.5 to 1.3 the output signal decreased to 50% of the initial value. It suggests the good sensitivity of the double layer capillary waveguide. The presented sensor was applied to determine the industrial oil temperature within the range of 10-70 °C. It corresponds to the oil refractive index change from 1.370 to 1.385. The main advantages of the presented sensor are: fast measurements, electrical isolation between the liquid measured and the electrical equipment used as well as continuous monitoring of the measured value without change of the sample. The described capillary optical fibre sensor is useful for automation and remote control of many industrial processes

UV Radiation Detection Using Optical Sensor Based on Eu3+ Doped PMMA

Progress in UV treatment applications requires new compact and sensor constructions. In the paper a hybrid (organic-inorganic) rare-earth-based polymeric UV sensor construction is proposed. The efficient luminescence of poly(methyl) methacrylate (PMMA) matrix doped by europium was used for testing the optical sensor (optrode) construction. The europium complex assures effective luminescence in the visible range with well determined multi-peak spectrum emission enabling construction of the optrode. The fabricated UV optical fibre sensor was used for determination of Nd:YAG laser intensity measurements at the third harmonic (355 nm) in the radiation power range 5.0-34.0 mW. The multi-peak luminescence spectrum was used for optimization of the measurement formula. The composition of luminescent peak intensity enables to increase the slope of sensitivity up to -2.8 mW-1. The obtained results and advantages of the optical fibre construction enable to apply it in numerous UV detection systems

The Prowler IADS Performance Evaluation Tool (PIPE)

The Prowler IADS Performance Evaluator is a computer simulation model of an airstrike protected by electronic countermeasures platforms. It is designed for integration into mission planning systems and analysis tools used to determine the effectiveness of electronic countermeasures or allocate scarce countermeasures equipment. PIPE's features include flexible hierarchical IADS specification, the capability to construct and calculate appropriate measures of performance, graphical presentation analysis results, mission visualizationNaval Postgraduate School, Monterey, California.http://archive.org/details/prowleriadsperfo00bailMonterey, California. Naval Postgraduate SchoolApproved for public release; distribution is unlimited

Tm3+//Ho3+Tm^{3+}//Ho^{3+}-Doped ASE Fibre Source for Mid-Infrared Sensor Applications

The infrared emission of $Tm^{3+}//Ho^{3+}$-doped antimony-silicate optical fiber has been presented. Luminescence at 2.1 μm corresponding to ⁵I₇ → ⁵I₈ transition in holmium was obtained by energy transfer between $Tm^{3+}$ and $Ho^{3+}$ ions. According to the Förster-Dexter theory, the efficiency of energy transfer of the $\text{}^3 F_4 (Tm^{3+}) \rightarrow \text{}^5 text{|}_7 (Ho^{3+})$ transition was calculated. The optimization of the activator content and the donor $(Tm^{3+})$/acceptor $(Ho^{3+})$ ions concentration ratio were conducted with the purpose of maximizing the efficiency of energy transfer. It made possible to select best-suited glass which was used to manufacture double-clad optical fiber. Strong and narrow bands of amplified spontaneous emission which formed as a result of energy transfer between thulium and holmium ions were observed in the fiber under exciting with radiation at 795 nm wavelength

Luminescent Polymer Optical Fibre Sensor for Temperature Measurement

In the paper the luminescence optical fiber used as a temperature sensor is presented. The new construction of rhodamine B doped, polymethyl methacrylate optical fibre with silver coating is shown. The fabrication process and luminescent properties of rhodamine B in sensing fibre are investigated. The attenuation and spectral shift of luminescence peak vs. the fibre length were measured and used for optimization of sensor construction. The characteristics of sensor for temperature range from 293 up to 343 K are shown. The relative sensitivity equal to -5.4× $10^{-4}$ $K^{-1}$ was obtained. The article presents also the potential applications of presented sensor

Effect of Temperature on Upconversion Luminescence in Yb3+//Tb3+Yb^{3+}//Tb^{3+} Co-Doped Germanate Glass

In the article effect of temperature on the cooperative energy transfer in germanate glass co-doped with $Yb^{3+}//Tb^{3+}$ under 976 nm laser diode pumping was investigated. The optimization of $Tb^{3+}$ concentration on the upconversion luminescence was determined. Strong luminescence at 489, 543, 586, 621 nm corresponding to $\text{}^{5}D_{4} \rightarrow \text{}^{7}F_{J}$ (J = 6,4,3) transitions and luminescence at 381, 415, 435 nm resulting from $\text{}^{5}D_{3}, \text{}^{5}G_6 \rightarrow \text{}^{7}F_{J}$ (J=6,5,4) transitions were presented. The highest upconversion emission intensity was obtained in glass co-doped with $0.7Yb_{2}O_{3}//0.7Tb_{2}O_{3}$ (mol%). The effect of temperature on the luminescent properties of germanate glass in the range of 5-250°C indicates the presence of competing phenomena: an increase in the effective absorption cross-section of $Yb^{3+}$ ions donor as a function of temperature and migration of energy between pairs of ions $Yb^{3+}-Yb^{3+}$ and of multiphonon excitation levels $\text{}^{7}F_{J}$