N. A. A. Norizan, M. Q. Lokman, S. N. F. Zuikafly, H. Yahaya, F. Ahmad, and S. W. Harun, “Q-switched Erbium Doped Fiber Laser Incorporating Zinc Oxide in Polyvinyl Alcohol as Passive Saturable Absorber”, JTEC, vol. 10, no. 2-7, pp. 27–31, Jul. 2018.