Wideband saturable absorption in few-layer molybdenum diselenide (MoSe2) for Q-switching Yb-, Er- and Tm-doped fiber lasers

TL;DR

This paper demonstrates the use of few-layer MoSe2 as a broadband saturable absorber for Q-switching fiber lasers at multiple wavelengths, highlighting its potential for advanced photonic applications.

Contribution

It introduces a novel MoSe2-polymer composite saturable absorber capable of broadband operation across Yb, Er, and Tm fiber lasers, expanding the material options for photonic devices.

Findings

Successful fabrication of MoSe2-based saturable absorber

Effective Q-switching at 1060 nm, 1566 nm, and 1924 nm

Edge-states enable sub-bandgap absorption in MoSe2

Abstract

We fabricate a free-standing molybdenum diselenide (MoSe2) saturable absorber by embedding liquid-phase exfoliated few-layer MoSe2 flakes into a polymer film. The MoSe2-polymer composite is used to Q-switch fiber lasers based on ytterbium (Yb), erbium (Er) and thulium (Tm) gain fiber, producing trains of microsecond-duration pulses with kilohertz repetition rates at 1060 nm, 1566 nm and 1924 nm, respectively. Such operating wavelengths correspond to sub-bandgap saturable absorption in MoSe2, which is explained in the context of edge-states, building upon studies of other semiconducting transition metal dichalcogenide (TMD)-based saturable absorbers. Our work adds few-layer MoSe2 to the growing catalog of TMDs with remarkable optical properties, which offer new opportunities for photonic devices.