Analysis and modelling of a novel approach for the interrogation unit of fiber bragg grating sensors using optical frequency domain reflectometry techniques
tarafından
Pala, Deniz, author.
Başlık
:
Analysis and modelling of a novel approach for the interrogation unit of fiber bragg grating sensors using optical frequency domain reflectometry techniques
Yazar
:
Pala, Deniz, author.
Yazar Ek Girişi
:
Pala, Deniz, author.
Fiziksel Tanımlama
:
xii, 95 leaves:+ 1 computer laser optical disc.
Özet
:
The main purpose of this thesis is to demonstrate the feasibility of using polarization properties of FBGs interrogated by OFDR for quasi-distributed sensing applications. A fiber Bragg grating (FBG) is a constant and periodic refractive index value modulation within the core along an optical fiber. This modification is generally obtained by exposing the fiber core of a photosensitive optical fiber to an intense ultraviolet (UV) interference pattern. At the fabrication process of Bragg gratings, only one side of the fiber expose to UV light. As a result, refractive index change is not constant at the cross section of fiber. This non-uniformity on the refractive index gives rise to photo-induced birefringence which combines with the birefringence resulting from the slightly elliptical shape of the optical fiber and creates a global birefringence value. In the presence of the birefringence, the reflection (transmission) spectrum of Bragg grating is degenerated into two reflection (transmission) spectra corresponding to a pair of orthogonal polarization modes (x and y modes). The ratio between maximum and minimum optical transmitted power of these modes are defined as Polarization Dependent Loss (PDL). We analyzed the reflection spectrum, transmission spectrum and the PDL of the cascaded FBGs interrogated by an OFDR by the way of simulations. Based on the simulation results, we demonstrated the feasibility of a novel FBG interrogation method which can be implemented in quasi-distributed strain sensors embedded into composite materials.
Konu Başlığı
:
Optical fibers
Bragg gratings
Yazar Ek Girişi
:
Yüksel Aldoğan, Kıvılcım
Tüzel Kişi Ek Girişi
:
İzmir Institute of Technology. Electronics and Communication Engineering.
Tek Biçim Eser Adı
:
Thesis (Master)--İzmir Institute of Technology: Electronics and Communication Engineering.
İzmir Institute of Technology: Electronics and Communication Engineering--Thesis (Master).
Elektronik Erişim
:
Library | Materyal Türü | Demirbaş Numarası | Yer Numarası | Durumu/İade Tarihi |
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IYTE Library | Tez | T001221 | TK8306 .P35 2014 | Tez Koleksiyonu |