Abdul-Razak, Furat.y. “Transmission Spectrum Shifting By Varying Ambient Refractive Index in LPFG”. Al-Rafidain Engineering Journal (AREJ) 20, no. 2 (April 1, 2012): 131–139. Accessed November 12, 2025. https://jpm.uomosul.edu.iq/index.php/arej/article/view/30708.