Louis-Rafaël Robichaud

Watt-level fiber-based femtosecond laser source tunable from 2.8 to 3.6 μm

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.

Compact 3–8 μm supercontinuum generation in a low-loss As 2 Se 3 step-index fiber

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 ∼5  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.

High power tunable ultrafast fiber laser emitting above 3 μm

Upcoming applications in material processing, countermeasures, remote sensing and spectroscopy will rely on the development of simple and reliable sources that generate intense laser pulses in the mid-IR spectral region (3–20 μm). Fiber lasers are certainly among the most promising candidates for such applications. Mid-IR ultrafast fiber lasers have been recently demonstrated using Er3+- and Ho3+-doped fluoride glass fibers [1, 2]. However, the emission spectra of these soliton fiber lasers are currently limited to wavelengths below 3 μm. The energies and peak powers of the generated pulses also remain modest (respectively < 7 nJ and < 50 kW) as compared to existing mid-IR solid-state laser systems based on parametric conversion.

Mid-IR supercontinuum generation via amplified picosecond pulses in a multimaterial AsSe/AsS step-index fiber

Directional mid-lR (3–20μm) light sources are required for remote sensing spectroscopic applications in various fields such as medicine, environment and defense & security. Mid-IR supercontinuum (SC) sources are one of the most promising solution since they offer both wide spectral coverage and high spectral power density along with a good beam quality. For practical purposes, fiber-based sources are highly attractive due to their ruggedness, compactness and reliability. Recently, Gauthier et al. reported a new cost-effective approach by generating a SC from 2.6 to 4.2 μm via the amplification of 400 ps pulses at 2.8 μm in an Er:ZrF4 fiber amplifier [1]. In later experiments, the SC spectral coverage was extended up to 5.4 μm and 8 μm by respectively cascading lnF3 or As2Se3 step-index fibers at the end of the Er-doped amplifier [2, 3]. In all these demonstrations, the long-wavelength edge of the SC was limited by propagation losses (material or mode confinement). In this study, we report an order of magnitude improvement vs [3] in term of average power for a SC extending up to 8.9 μm (at −30 dB level) by using a 2.5 m low-loss multimaterial (AsSe/AsS) chalcogenide glass (ChG) step-index fiber having a high numerical aperture.

Supercontinuum Generation up to 8 µm in a Low Loss As 2 Se 3 Step-Index Fiber

We report the first fiber-based mid-IR supercontinuum extending up to 8 µm generated in a low-loss commercial step index As2Se3 fiber. Article not available.