Q-Switching and Mode-Locking in Highly Doped Zr O -Al O -Er O -Doped Fiber Lasers Using Graphene as a Saturable Absorber

• Published in: IEEE journal of selected topics in quantum electronics 2014-01, Vol.20 (1), p.9-16
• Main Authors: Ahmad, Harith, Thambiratnam, Kavintheran, Muhammad, Farah Diana, Zulkifli, Mohd Zamani, Zulkifli, Ahmad Zarif, Paul, Mukul Chandra, Harun, Sulaiman Wadi
• Format: Article
• Language: English
• Subjects: Graphene; Graphene-based saturable absorber; Laser excitation; Laser mode locking; mode-locking; Optical fiber amplifiers; Power lasers; Pump lasers; Q-switching; Zirconia-Erbium-doped fiber (Zr-EDF)
• ISSN: 1077-260X; 1558-4542
• DOI: 10.1109/JSTQE.2013.2272459

The application of graphene as a saturable absorber (SA) for generating Q-switched and mode-locked pulses in a Zirconia-Erbium-doped fiber (Zr-EDF) laser is explored. Graphene-based SAs have a very wide operational range, which complements the extended operational bandwidth of the Zr-EDF. The Zr-EDF has an erbium concentration of about 4320 ppm, with absorption rates of 22.0 and 58.0 dB/m at 987 and 1550 nm. The system is capable of generating Q-switched pulses with pulsewidths and energies of 4.6 μs and 16.8 nJ, respectively, as well as peak powers of 3.6 mW at a repetition rate of 50.1 kHz. The Zr-EDF laser can also generate mode-locked pulses with pulsewidths, average output powers, pulse energies, and peak powers of 730 fs, 1.6 mW, 23.1 pJ, and 31.6 W, respectively, at a repetition rate of 69.3 MHz. Both the Q-switched and mode-locked output pulses are highly stable, allowing for their application in a multitude of real-world applications.