1.06 {\mu}m Q-switched ytterbium-doped fiber laser using few-layer topological insulator Bi2Se3 as a saturable absorber

TL;DR

This paper demonstrates for the first time the passive Q-switching of an ytterbium-doped fiber laser at 1.06 μm using few-layer topological insulator Bi2Se3 as a saturable absorber, achieving stable pulsed laser operation.

Contribution

It introduces a novel fiber-integrated saturable absorber based on few-layer Bi2Se3 topological insulator for Q-switching at 1.06 μm, expanding the application of TIs as wavelength-independent SAs.

Findings

Achieved stable Q-switching at 1.06 μm with shortest pulse duration of 1.95 μs.

Maximum pulse energy of 17.9 nJ and tunable repetition rate from 8.3 to 29.1 kHz.

Demonstrated potential of TI as a wavelength-independent saturable absorber.

Abstract

Passive Q-switching of an ytterbium-doped fiber (YDF) laser with few-layer topological insulator (TI) is, to the best of our knowledge, experimentally demonstrated for the first time. The few-layer TI: Bi2Se3 (2-4 layer thickness) is fabricated by the liquid-phase exfoliation method, and has a low saturable optical intensity of 53 MW/cm2 measured by the Z-scan technique. The optical deposition technique is used to induce the few-layer TI in the solution onto a fiber ferrule for successfully constructing the fiber-integrated TI-based saturable absorber (SA). By inserting this SA into the YDF laser cavity, stable Q-switching operation at 1.06 {\mu}m is achieved. The Q-switched pulses have the shortest pulse duration of 1.95 {\mu}s, the maximum pulse energy of 17.9 nJ and a tunable pulse-repetition-rate from 8.3 to 29.1 kHz. Our results indicate that the TI as a SA is also available at 1 {\mu}m waveband, revealing its potential as another wavelength-independent SA (like graphene).