مشاركة
الليف البلوري الفوتوني لاستشعار المجال المغناطيسي == Photonic crystal fiber magnetic sensor
اسم المؤلف:
احمد عدنان محمد
اسم المشرف:
عبد الهادي مطشر الجنابي
الموضوع العام:
علوم الليزر
السنة:
2015
الموضوع الدقيق:
تطبيقات الليزر في هندسة الالكترونيك والاتصالات
الدرجة:
ماجستير
الجامعة:
جامعة بغداد - معهد الليزر للدراسات العليا
اللغة:
الانكليزية
مكان الجامعة:
بغداد
الصفحات الاولى:
29T196 - p.pdf
المستخلص:
Photonic crystal fiber (PCF) is widely used for sensing applications. In this work, magnetic sensor based on solid core - PCFs for sensing magnetic field was presented. The general structure of the sensor applied is by splicing short lengths of PCF (LMA - 10) with conventional single mode fiber (SMF - 28) in one side and using free space connector from other side. A laser diode with different wavelengths (850, 1060 and 1300 nm) has been used as a light source, where a high sensitive optical spectrum analyzer (OSA) was used to monitor and record the transmitted/reflected spectra.The present work demonstrates the results of the infiltration of the air holes for the PCFs by fluids instead of air. For magnetic sensing, the magnetic fluids being used were prepared and standard ????????3????4 to infiltrate the air holes for the solid core PCF (LMA - 10) which leads to change in the effective refractive index of the PCF, which in turn affects the transmission of the laser inside the PCF due to the value of the refractive indices of the magnetic fluids. The experiments show that the power of transmissionspectrum of the laser had decreased after infiltration without any change in central wavelength of the laser diode the reason is that after PCF air holes infiltration, the effective refractive index has been changed but still within total internal reflectionwhich leads to loss of some fundamental modes, in turn leads to decrease the power of transmission spectrum. The decrease of the transmitted power in the case of standard has been higher than it in the case of prepared ????????3????4 because of the differencein concentration between standard and prepared magnetic fluids. The power of transmission spectrum after PCF infiltration will be increased with increasing magnetic field. Higher sensitivity has been obtained that reached 5.809 nW/mT which consideredhigher than previously published works on PCF magnetic sensors.
