RESUMO
We report the demonstration of a fiber-based supercontinuum source delivering up to 825 mW of average output power between 2.5 and 5.0 µm generated in all-normal dispersion regime. The pumping source consists of an amplified ultrafast Er3+:ZrF4 fiber laser providing high peak power femtosecond pulses at 3.6 µm with an average output power exceeding the watt-level. These pulses are spectrally broadened through self-phase modulation using commercial chalcogenide-based step-index fibers. Al2O3 anti-reflection coatings were sputtered on chalcogenide fiber tips to increase the launching efficiency from 54% to 82%, making this record output power possible, and thus confirming that such coatings can support watt-level pumping with intense femtosecond pulses. To the best of our knowledge, this result represents the highest average output power ever achieved from a As2Se3-based mid-IR supercontinuum source with the potential of a high degree of coherence.
RESUMO
We report on a splice-free erbium-doped all-fiber laser emitting over 20 W at a wavelength of 1610 nm, with a slope efficiency of 19.6 % and an overall efficiency of 18.3% with respect to the launched pump power at 976 nm. The simple cavity design takes advantage of fiber Bragg gratings written directly in the gain fiber through the polymer coating and clad-pumping from a single commercial pump diode to largely simplify the assembling process, making this cavity ideal for large-scale commercial deployment. Two single-mode and singly erbium-doped silica fibers were fabricated in-house: the first to assess the effects of a high erbium concentration (0.36 mol.% Er2O3), yielding a low efficiency of 2.5 % with respect to launched pump power, and the second to achieve the improved result mentioned above (0.03 mol.% Er2O3). Numerical simulations show the link between the performance of each cavity and ion pair-induced quenching.
RESUMO
We report on infrared supercontinuum (SC) generation through subsequent nonlinear propagation in concatenated step-index fluoride and As2Se3 fiber. These fibers were pumped by an all-fiber laser source based on an erbium amplifier followed by a thulium power amplifier. ZBLAN and InF3 fibers were compared for the concatenated scheme. The broadest SC produced was achieved by optimizing the length of the InF3 fiber. This arrangement allowed the generation of 200 mW infrared SC with high spectral flatness and spanning from 1.4 µm to 6.4 µm.
RESUMO
A mid-infrared supercontinuum source spanning from 3 to 8 µm is demonstrated using a low-loss As2Se3 commercial step-index fiber. A maximum average output power of 1.5 mW is obtained at a low repetition rate of 2 kHz. Thanks to the low NA step-index fiber, the output is single mode for wavelengths above â¼5 µm. The pump source consists of an erbium-doped ZrF4-based in-amplifier supercontinuum source spanning from 3 to 4.2 µm. The effects of both the pump power and As2Se3 fiber length on the output characteristics are studied. To the best of our knowledge, this is the first compact supercontinuum source ever reported to reach 8 µm in a standard step-index fiber.
RESUMO
The development of compact and reliable ultrafast sources operating in the mid-infrared region could lead to major advances in both fundamental and applied sciences. In this Letter, we report on a simple and efficient laser system based entirely on erbium-doped fluoride glass fibers that generates high-energy Raman soliton pulses tunable from 2.8 to 3.6 µm at a high average output power. Stable 160 fs pulses at 3.4 µm with a maximum energy of 37 nJ, a corresponding average output power above 2 W, and an estimated peak power above 200 kW are demonstrated. This tunable source promises direct applications in laser processing of polymers and biological materials.
