The master’s thesis entitled “A laser chemical refractive index sensor based on an offset design using optical fibers” was discussed at the Institute of laser for Graduate Studies at the University of Baghdad, by student Saraa Jamal Ibrahim and supervised by Asst. Prof. Dr. Hanan Jaafar Taher.
The aim of this study was to design and manufacture a chemical sensor structure using offset technology between two identical pieces of coreless fibers divided between two pieces of single-mode fibers to measure the refractive index and detect poor storage of liquid pharmaceuticals.
Four different lengths of identical coreless fiber sections were tried from 10 mm to 25 mm for each displacement from 2.6 µm to 18.3 µm. When the refractive indices of the samples increase, the wavelength of the light shifts more towards the red spectrum and the sensitivity increases with a decrease in the length of the sensing region and the offset shift. To enhance performance, the coreless optical fiber’s optimized structure, which already had the ideal length and offset, underwent a one-piece diameter reduction to create waists of three different diameters.
