High power mid-infrared supercontinuum generation in a single-mode ZBLAN fiber with up to 218 W average output power

Kun Liu,Jiang Liu,Hongxing Shi,Pu Wang,Fangzhou Tan

doi:10.1364/oe.22.024384

Abstract

We report high power mid-infrared (mid-IR) supercontinuum (SC) generation in a single-mode ZBLAN (ZrF₄-BaF₂-LaF₃-AlF₃-NaF) fiber with up to 21.8 W average output power from 1.9 to beyond 3.8 μm pumped by amplified picosecond pulses from a single-mode thulium-doped fiber (TDF) master oscillator power amplifier (MOPA). The optical-optical conversion efficiency from the 793 nm pump laser of the last stage thulium-doped fiber amplifier (TDFA) to mid-IR SC output is 17%. It is, to the best of our knowledge, the highest average power mid-IR SC generation from a ZBLAN fiber to date.

Highlights

High-brightness fiber-based SC sources with good beam quality are needed for various applications such as frequency metrology, remote sensing and medical imaging
The seed source is a mode-locked fiber oscillator working at 1963 nm, which consists of a ~90 cm long thulium/holmium codoped fiber (THDF), a SMF28 fiber, a semiconductor saturable absorber mirror (SESAM) and a narrow bandwidth fiber Bragg grating (FBG)
We have demonstrated high power mid-IR SC generation in a single-mode ZBLAN fiber pumped by amplified picosecond pulses from a single-mode thulium-doped fiber (TDF) master oscillator power amplifier (MOPA)

Summary

Introduction

High-brightness fiber-based SC sources with good beam quality are needed for various applications such as frequency metrology, remote sensing and medical imaging. Q. Yang et al reported 13 W average output power and spectrum spanning from 1.9 to 4.3 μm SC generation in a single-mode ZBLAN fiber pumped by a large mode area (LMA) TDF MOPA [17], which was the highest average power SC generation from a ZBLAN fiber ever reported. The single-mode TDFA has a matched mode field diameter with the single-mode ZBLAN fiber It can directly pump the ZBLAN fiber to generate high power SC and even higher than pumped by LMA TDFA. We report a higher power mid-IR SC generation with up to 21.8 W average output power and spectrum spanning from 1.9 to beyond 3.8 μm in a single-mode ZBLAN fiber pumped by a single-mode TDF MOPA. A cascaded single-mode ZBLAN fiber further broadens the output spectrum from the TDFA to beyond 3.8 μm with average power of 21.8 W. The SC system has an optical-optical conversion efficiency of 17% with respect to 793 nm pump laser of the last stage TDFA

Experimental setup

High power mid-IR SC generation with 42 MHz picosecond pulses pump

Findings

Conclusions