Widely wavelength tunable gain-switched Er3+-doped ZBLAN fiber laser around 2.8 μm.

Chen Wei,Hongyu Luo,Yong Liu,Yanjia Lyu,Hongxia Shi,Han Zhang

doi:10.1364/oe.25.008816

Abstract

In this paper, we demonstrate a wavelength widely tunable gain-switched Er3+-doped ZBLAN fiber laser around 2.8 μm. The laser can be tuned over 170 nm (2699 nm~2869.9 nm) for various pump power levels, while maintaining stable μs-level single-pulse gain-switched operation with controllable output pulse duration at a selectable repetition rate. To the best of our knowledge, this is the first wavelength tunable gain-switched fiber laser in the 3 μm spectral region with the broadest tuning range (doubling the record tuning range) of the pulsed fiber lasers around 3 μm. Influences of pump energy and power on the output gain-switched laser performances are investigated in detail. This robust, simple, and versatile mid-infrared pulsed fiber laser source is highly suitable for many applications including laser surgery, material processing, sensing, spectroscopy, as well as serving as a practical seed source in master oscillator power amplifiers.

Highlights

Mid-infrared (Mid-IR) laser sources with emission wavelengths around 3 μm, which lie in one of the two main atmospheric windows and well within the strong water absorption band, are of great scientific and technical interests as a result of their widespread applications in remote sensing, defense, highly precise biological tissue cutting, spectroscopy, chemical and biomolecular sensing, semiconductor micro-structuring, etc [1,2,3,4]
With the increase in pump power, the continuous wavelength tuning range was fast shrank as a result of the narrowed gain bandwidth caused by enhanced reabsorption process and weakened population inversion associated with shorter-wavelength emissions
The results suggested that this laser source was a reliable and cost-effective solution for laser surgery, sensing, spectroscopy and other industrial applications of pulsed lasers in the 3 μm spectral region

Summary

Introduction

Mid-infrared (Mid-IR) laser sources with emission wavelengths around 3 μm, which lie in one of the two main atmospheric windows and well within the strong water absorption band, are of great scientific and technical interests as a result of their widespread applications in remote sensing, defense, highly precise biological tissue cutting, spectroscopy, chemical and biomolecular sensing, semiconductor micro-structuring, etc [1,2,3,4]. For some practical applications, such as selective excitation, spectroscopic sensors [14] and laser surgery [15], other than high output power, broad wavelength tuning range of the mid-IR sources are of particular concerned. Rare earth ion doped fluoride fiber lasers have been shown to offer broad tuning characteristics in the Mid-IR spectral region not covered with semiconductor sources [14,16,17,18,19,20,21,22,23,24,25,26]. In 2010, Shigeki Tokita et al reported a ten-watt-level high power Er3+-doped ZBLAN fiber laser with a continuous wavelength tuning range of 110 nm from 2770 nm to 2880 nm [21]. The continuous wavelength tuning range of Er3+-doped

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Conclusion