Watt-level passively Q-switched heavily Er(3+)-doped ZBLAN fiber laser with a semiconductor saturable absorber mirror.

Yanlong Shen,Hongwei Chen,Mengmeng Tao,Yishan Wang,Ke Huang,Kunpeng Luan,Aiping Yi,Guobin Feng,Jinhai Si

doi:10.1038/srep26659

Abstract

A diode-cladding pumped mid-infrared passively Q-switched Er3+-doped ZBLAN fiber laser with an average output power of watt-level based on a semiconductor saturable absorber mirror (SESAM) is demonstrated. Stable pulse train was produced at a slope efficiency of 17.8% with respect to launched pump power. The maximum average power of 1.01 W at a repetition rate of 146.3 kHz was achieved with a corresponding pulse energy of 6.9 μJ, from which the maximum peak power was calculated to be 21.9 W. To the best of our knowledge, the average power and the peak power are the highest in 3 μm region passively Q-switched fiber lasers. The influence of gain fiber length on the operation regime of the fiber laser has been investigated in detail.

Highlights

By employing various saturable absorbers, including InAs epilayers[20], Fe2+:ZnSe crystal[19,21], graphene[19,22] and SESAM12,23,24
We report a watt-level passively Q-switched fluoride fiber laser at 3 μm waveband using a SESAM
A pulse energy of 6.9 μJ and a pulse width of 315 ns at a repetition rate of 146.5 kHz are achieved with a peak power of exceeding 21 W by employing a heavily Er3+-doped ZBLAN fiber as short as 0.9 m

Summary

Introduction

By employing various saturable absorbers, including InAs epilayers[20], Fe2+:ZnSe crystal[19,21], graphene[19,22] and SESAM12,23,24. Zhu et al demonstrated a passively Q-switched Er3+-doped and Ho3+-doped ZBLAN fiber lasers with pulse widths of 370 ns and 800 ns, pulse energies of 2.0 μJ and 460 nJ at repetition rates of 161 kHz and 105 kHz by using a Fe2+:ZnSe crystal, respectively[19,21]. With the emergence of new materials used as saturable absorbers, topological insulator and black phosphorus have been demonstrated to have the capability of generating mid-infrared laser pulses very recently[25,26]. During these passively Q-switched demonstrations, the maximum average power and the maximum peak power were 629.2 mW and 8.4 W, respectively. The average power and the peak power, to our knowledge, are current recorded in passively Q-switched fiber lasers at mid-infrared region

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Discussion

Conclusion