Q-switched thulium-doped fiber laser operating at 1940 nm region using a pencil-core as saturable absorber

Abstract

Q-switched thulium-doped fiber laser (TDFL) is demonstrated using pencil-core flakes as a saturable absorber (SA) for the first time. The SA was fabricated by exfoliating pencil-core flakes on adhesive tape surface, then repeatedly folded over the tape until the flakes homogenously deposited on the tape. A small piece of the tape is sandwiched between two ferrules and incorporated in TDFL cavity to realize a stable Q-switching pulse train. By increasing the 1552-nm pump power from 389 to 431 mW, the repetition rate of the TDFL increases from 14.95 to 34.60 kHz while the pulse width decreases from 6.70 to 4.69 μs. The maximum pulse energy of 46.05 nJ is generated with repetition rate and pulse width of 21.25 kHz and 6.27 μs, respectively. To the best our knowledge, this is a first demonstration SA from mundane object as alternative to commercial bulk graphite for Q-switched fiber laser.

Keywords:

• Q-switching
• thulium-doped fiber
• passive saturable absorber

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the PPP, University of Malaya [grant number PG098-2014B]; MOSTI [grant number SF014-2014].