Scaling all-fiber mid-infrared supercontinuum up to 10  W-level based on thermal-spliced silica fiber and ZBLAN fiber

Abstract

We demonstrate an integrated all-fiber mid-infrared (mid-IR) supercontinuum (SC) source generated by a 1.95 μm master oscillator power amplifier system and a single-mode ZBLAN (ZrF 4 -BaF 2 -LaF 3 -AlF 3 -NaF) fiber. The maximum average output power is 10.67 W with spectral bandwidth covering from ∼1.9 to 4.1 μm. The single-mode ZBLAN fiber and silica fiber are thermal-spliced to enhance the robustness and practicability of the system. It is, to the best of our knowledge, the first high-power integrated compacted all-fiber mid-IR SC source based on thermal-spliced silica fiber and ZBLAN fiber. ©

Broadband and top-flat mid-infrared supercontinuum generation with 3.52 W time-averaged power in a ZBLAN fiber directly pumped by a 2-µm mode-locked fiber laser and amplifier

“…Further power scaling-up was limited by the damage to the ZBLAN fiber output facet. Both the SC power conversion towards the red wavelengths and flatness of output spectrum are better than the recent results [15][16][17][18][19]. It also shows that applying a SESAM modelocked TDFL&A delivering pulses with tens of picoseconds and a low loss ZBLAN fiber it is possible to develop a high power and super flat mid-IR SC source with very good power distribution towards the mid-IR spectral region.…”

“…Soon after that, the same group demonstrated a record 24.3 W SC generation in a single-mode ZBLAN fiber pumped by a 2-µm TDFA with a spectrum spanning from 1.9 to 3.3 µm [18]. More recently, a 10-W-level SC with a spectrum extending from ~ 1.9 to 4.1 µm, generated out of a fluorozirconate fiber pumped by a 1.95 µm MOPA system with a SESAM modelocked TDFL, was also reported by Zheng at al [19].…”

“…When mid-IR spectral region is concerned, soft glass fibers, including tellurite [5,6], fluoride [1,[7][8][9][10][11][12] and chalcogenide [13,14] fibers can be adopted as nonlinear media. However, among all soft glass fibers, only heavy metal fluoride fibers, including fluorozirconate (ZBLAN) [15][16][17][18][19] and fluoroindate (InF 3 ) [20,21] are technologically mature to be used for multi Watt level SC generation. Because they exhibit a zero-dispersion wavelength (ZDW) within the range of ~ 1.5-1.9 µm they can be effectively pumped in the anomalous dispersion region, which facilitates efficient continuum extension towards longer wavelengths.…”

“…Different types of pulsed thulium-doped fiber-based laser systems, such as mode-locked [18,19], Q-switched and mode-locked [8,23] as well as gain-switched and modelocked [24,25] providing femtosecond [7] and picosecond [23,25] pulses, have been already proposed to pump fluoride fibers. In particular, CW model-locked fiber lasers followed by a cascade of amplifiers delivering optical pulses with pulse widths in the picoseconds range allow scaling output SC power to over 10 W, while being relatively easy in realization.…”

Mid-infrared Supercontinuum Generation to ∼4.7 μm in a ZBLAN Fiber Pumped by an Optical Parametric Generator

“…An ultra-wide SC spectrum extending from ultraviolet to 6.28 μm [13], as well as an SC source emitting an average power as high as 24.3 W [18], generated out of ZBLAN fibers, have been demonstrated. Furthermore, it has been shown that single-mode fluoride fibers can be successfully fusion-spliced with other fluoride fibers [12] and even with silica fibers [19], [20], providing an all-fiber format for an SC source. Notwithstanding such impressive results, selecting a proper nonlinear medium and pump pulse parameters that affect the efficiency of broadband mid-IR SC evolution, featured by high flatness and a long cut-off wavelength, remains a challenge.…”