Measurement of Numerical aperture of optical fibre
1.http://www.nitttrchd.ac.in/sitenew1/app_sc/list/NA%20of%20Optical%20Fibers-%20FO%20Apparatus.pdf
2. https://www.tau.ac.il/~lab3/OPTICFIBERS/opticfibers.html
3.https://www.cmu.edu/biolphys/smsl/teaching/IntermedOptics/IntOptics_data/lab%20manuals/Lab6%20-%20Optical%20Fibers.pdf
4.http://www.kfupm.edu.sa/departments/ee/SiteCollectionDocuments/EE420_Lab_Manual.pdf
5. http://denethor.wlu.ca/pc481/pc481.pdf