Development of D -type fiber optic sensors for detection of refractive index variation in evanescent wave field /

Download
index.pdf
2014
Güleryüz, Burcu
Show full item record
125
views
31
downloads
The purpose of this study is to design, construct, develop and test D-type multimode fiber optic (F/O) sensors based on evanescent wave field sensing. A comprehensive work has been performed both theoretically and experimentally using a geometrical modification approach to improve the sensors response in different manners for detecting the refractive index (RI) variations and bio-molecular interactions in aqueous environment. In this study, the D-type F/O sensors performance was improved utilizing optical waveguide (OWG) and surface plasmon resonance (SPR) modes in evanescent wave field. Development steps of sensors are; fabrication and characterization of silicon V channels (supporting elements), the F/O cable preparation, adhesion, mechanical lapping and polishing, and assembling the Field Assembly Connectors (FC connectors). These steps are explained in detail and sensor performances are demonstrated for RI changes between 1.33 and 1.47. The highest sensitivity is found to be 2x10 5 refractive index unit (RIU) for the zone of 1.44 and 1.46 RIU. In addition, thin gold film is deposited on the D-type F/O sensors to excite surface plasmon (SP) mode. It is shown that the SP mode can amplify the sensors ensitivity between the 1.33 and 1.44 RIU being known as the Dynamic range to monitor the bio-molecular İnteractions. Furthermore, in order to tune thin gold film thickness and roughness for a better sensor response, a novel surface modification approach is introduced with plasma etching process.
Optical wave guides., Optical fiber detectors., Optical detectors., Refractive index.
http://etd.lib.metu.edu.tr/upload/12617912/index.pdf
https://hdl.handle.net/11511/24076
Graduate School of Natural and Applied Sciences, Thesis

Suggestions

Development of an optical system calibration and alignment methodology using Shack-Hartmann wavefront sensor
Adil, Fatime Zehra; Konukseven, Erhan İlhan; Balkan, Raif Tuna; Department of Mechanical Engineering (2013)
Shack-Hartmann wavefront sensors are commonly used in optical alignment, ophthalmology, astronomy, adaptive optics and commercial optical testing. Wavefront error measurement yields Zernike polynomials which provide useful data for alignment correction calculations. In this thesis a practical alignment method of a helmet visor is proposed based on the wavefront error measurements. The optical system is modeled in Zemax software in order to collect the Zernike polynomial data necessary to relate the error me...
Optical system design of direct detection short-pulsed laser proximity sensor
Korkmaz, Emrah; Yerci, Selçuk; Demir, Şimşek; Department of Micro and Nanotechnology (2017)
In this study, we designed a Laser Proximity Sensor system that measures the distance by analyzing the echo signal reflected from object using time-of-flight principle. The sensor makes a direct-detection using a short-pulsed laser and is capable of detecting objects and measuring distances in a range between 0.5 m and 10 m far from the system. Reflectivities of objects are assumed to lie between 20% and 90% and obeying to Lambertian BSDF (Bi-Directional Scatter Distribution Function). A mathematical model ...
Design and Optimization of Nanoantennas for Nano-Optical Applications
Işıklar, Göktuğ; Ergül, Özgür Salih; Department of Electrical and Electronics Engineering (2020-9)
In this study, design and simulation of plasmonic nanoantenna structures to obtain high power enhancement capabilities at optical frequencies, as well as utilization of nanoantennas for imaging and sensing applications are presented. Plasmonic characteristics of nanoantennas, which depend on many parameters, such as material, frequency, geometry, and size, are investigated in detail via computational analyses of various nanoantenna structures. Numerical solutions of electromagnetic problems are performe...
DESIGN, ANALYSIS AND IMPLEMENTATION OF QUARTER-WAVE ABSORBER STRUCTURE FOR UNCOOLED INFRARED DETECTORS WITH HIGH FILL FACTOR
Cetin, Ramazan; Erturk, Ozan; Akın, Tayfun (2018-09-14)
This study presents design, analysis, optimization, and fabrication of umbrella structures as an efficient quarter wave absorber within the Long Wave Infrared (LWIR) range for uncooled IR detectors. Both the effect of the ni-chrome (NiCr) layer and effect of varying pixel pitch sizes on the IR absorption performance of the umbrella structures are examined. An average of 96% absorption is measured for the optimized case within the LWIR range.
Finite element analysis and tests of composite beams with fiber bragg grating sensors under torsional load for structural health monitoring applications
Karataş, Cansu; Yaman, Yavuz; Department of Aerospace Engineering (2017)
In this thesis, feasibility of Fiber Bragg Grating sensors for Structural Health Monitoring applications of composite structures is studied. The method and essentials for the manufacturing process of composite beams with embedded Fiber Bragg Grating sensors are presented. Composite beams instrumented with surface bonded and embedded Fiber Bragg Grating sensors are tested under static torsional load. In addition, Finite Element Analyses of composite beams under torsional load is conducted using the commercia...
Citation Formats
B. Güleryüz, “Development of D -type fiber optic sensors for detection of refractive index variation in evanescent wave field /,” M.S. - Master of Science, Middle East Technical University, 2014.
METU IIS - Integrated Information Service open@metu.edu.tr