Passively Q-switched erbium-doped fiber laser using quantum dots CdSe embedded in polymer film as saturable absorber

• Main Authors: Ismail, Ezzatul Irradah, Kadir, N.A.A., Latiff, Anas Abdul, Arof, Hamzah, Harun, Sulaiman Wadi
• Format: Article
• Published: Springer 2019
• Subjects: QC Physics; TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://eprints.um.edu.my/24083/; https://doi.org/10.1007/s11082-019-1897-6

We demonstrate a passively Q-switched erbium doped fiber laser (EDFL) based on quantum dots (QD) CdSe as a saturable absorber (SA). The synthesized CdSe powder was embedded into a poly(methyl methacrylate) (PMMA) using emulsion polymerization process. The film is sandwiched between two fiber connector via an adapter to form a fiber-compatible SA device. By integrating the SA device into the EDFL ring cavity, the stable Q-switched operation is achieved at 1559.35 nm as the pump power is varied within 30–118 mW. The laser has a pump threshold of 20.4 mW. The pulse repetition rate shows an increasing trend from 33.2 to 68.45 kHz, whereas the pulse width exhibits a decreasing trend from 10.04 to 4.30 μs as the pump power is increased from 30 to 118 mW. The highest pulse energy of 11.83 nJ is obtained at a pump power of 118 mW. These results indicate that QD CdSe is a promising SA for Q-switching laser operation. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.