Development of photonic crystal fiber (PCF) based sensing and absorption spectroscopic measurement

• Main Author: Fu, Moting.
• Other Authors: Shum Ping
• Format: Final Year Project
• Language: English
• Published: 2012
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics
• Online Access: http://hdl.handle.net/10356/50218
• Institution: Nanyang Technological University

This project consists of two sub-projects. The first sub-project aims to design a computer interface for semi- or fully automated control of Photonic Crystal Fiber (PCF) based sensing by using Laboratory Virtual Instrumentation Engineering Workbench (LabVIEW). PCF based interferometric biosensing experiment is set up for verification of the program. In particular, a highly sensitive refractometer based on PCF interferometry is designed to evaluate the relationship between changes of wavelengths to Refractive Index (RI). By using fusion splicing technique, a short section of PCF (~3mm) was spliced with conventional Single Mode Fiber at both ends. The experimental results show a positive linear relationship which indicates efficient and accurate readings using LabVIEW. The second sub project was absorption spectroscopic measurement which aims to develop a laboratory prototype for absorption spectroscopy using PCF as a sensitive platform for hazardous material identification and quantitative analysis. The PCF is infiltrated with sample solution Copper Sulphate (CuSO4) by capillary force. The use of absorption spectroscopic technique enables the observation of absorption spectra and quantitative analysis can be conducted. By applying Lambert Beers’ Law, a positive linear relationship is demonstrated between absorbance of sample solution to its concentration and fiber length while altering one factor and keeping other conditions constant. Inaccuracies in the experimental measurements can be attributed to the large variation in splicing loss between different PCF samples. Selective infiltration technique and addition of other hazardous solutions are two recommendations suggested for future work.