Generation of watt-level supercontinuum covering 2-6.5 µm in an all-fiber structured infrared nonlinear transmission system

Abstract

We demonstrate a watt-level mid-infrared supercontinuum source, with the spectrum covering the infrared region from 2 to 6.5 µm, in an all-fiber structured laser transmission system. To further improve the SC spectral bandwidth, power and system compactness in the follow-up As2S3 fiber, we theoretically and experimentally explored some knotty problems that would potentially result in the As2S3 fiber end-facet failure and low SC output power during the high-power butt-coupling process and proposed an optimal coupling distance on the premise of the safety of As2S3 fiber end face. In addition, we also built a multi-pulse pumping model for the first time to more precisely estimate the SC spectral evolution in As2S3 fiber. This work will give an important reference to someone who is working on the all-fiber structured, high-power mid- and far-infrared supercontinuum source.

Mid-infrared supercontinuum generation in chalcogenide glass fibers: a brief review

“…Generally, fluoride fibers are always chosen as the firststage fiber in the cascading scheme because of the following excellent properties: 1) high damage threshold; 2) generating SC sources with > 3.5 μm long wavelength edge extending above the ZDW of typical step-index fluoride fibers around 1.5 μm; 3) high output power of up to 30 W [18]. Subsequently, this concept has been proved to be feasible by many experimental results [29,[76][77][78][79][80]. In [29], a MOPA pump laser with a repetition rate of 600 kHz shown in Fig.…”

“…Subsequently, this concept has been proved to be feasible by many experimental results [29,[76][77][78][79][80]. In [29], a MOPA pump laser with a repetition rate of 600 kHz shown in Fig. 12a was used to increase the average pump power to several tens of watts from the TDFA.…”

“…b Measured SC spectra from ZBLAN with different output powers. c Measured SC spectra from As 2 S 3 fiber with different output power versus the input power (Adapted with permission from [29], copyright the Optical Society) Fig. 13 a Setup of three-stage cascading scheme for all-fiber SC generation.…”

“…By contrast, ChG glasses have comparatively wider transparency window (over 20 μm) [26,27] and higher optical nonlinearity (up to a thousand times greater than that of silica glasses) [28], making them excellent candidates for MIR SC generation. To date, an ultrabroad SC generation spanning from 2 to 16 μm has been achieved in a Te-based ChG fiber [25], and a high SC output power reaching 1.13 W has also been realized in a cascaded As 2 S 3 fiber [29].…”

Recent Advances in Supercontinuum Generation in Specialty Fiber

“…In 2021, Woyessa et al demonstrated a stable and portable MIR SC laser source covering the bandwidth from 1.46-10.46 µm with an average output power of 86.6 mW and a repetition rate of 3 MHz in a fiber cascade comprising of silica, ZBLAN, and chalcogenide fibers pumped by 0.5 ns pulsed Er/Yb-MOPA without any amplifier stages [73]. Yan et al demonstrated a watt-level (1.13 W) MIR SC spanning from 2-6.5 µm in a butt coupled ZBLAN and As 2 S 3 cascaded fiber system pumped by a 1550 nm pulsed DFBL and few stages of thulium-doped fiber amplifier [74]. In 2019, C. R. Petersen et al reported 1.07-7.94 µm MIR SC with an average output power of 41 mW in an all fiber cascade comprising of ZBLAN PCF and Ge 10 As 22 Se 68 PCF taper.…”