Tunable Q-switched fiber laser based on saturable edge-state absorption in few-layer molybdenum disulfide (MoS₂).

Abstract

We fabricate a few-layer molybdenum disulfide (MoS₂) polymer composite saturable absorber by liquid-phase exfoliation, and use this to passively Q-switch an ytterbium-doped fiber laser, tunable from 1030 to 1070 nm. Self-starting Q-switching generates 2.88 μs pulses at 74 kHz repetition rate, with over 100 nJ pulse energy. We propose a mechanism, based on edge states within the bandgap, responsible for the wideband nonlinear optical absorption exhibited by our few-layer MoS₂ sample, despite operating at photon energies lower than the material bandgap.EJRK acknowledges support from the Royal Academy of Engineering (RAEng), through a RAEng Fellowship, RCTH from EPSRC (EP/G037221/1), GH from a CSC Cambridge International Scholarship, and TH from the RAEng (Graphlex). The authors also acknowledge ThorLabs for access to their technical drawings.This is the accepted manuscript. The final version is available at http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-22-25-31113. © 2014 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited