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In this study, we report the generation of multi-wavelength light sources through enhanced four-wave-mixing processes using a straightforward and adaptable dual-frequency Brillouin fiber laser. This passive optical and nonreciprocal cavity is first tested and analyzed with long fiber lengths up to 1 km in the 1.55 μm telecommunication C band and then in the 2-μm waveband. In the latter case, we demonstrate that our fiber cavity enables efficient multiple four-wave mixings, in the continuous-wave regime, which are commonly inaccessible in long silica-fibers due to increased losses. We also report on the tunable repetition rate from tens of GHz to hundreds of GHz, by simply changing the frequency spacing between the two continuous-wave pumps. The coherence limitations of our all-fiber system are discussed, along with the impact of the dispersion regime of the nonlinear fiber that forms the cavity.

Stimulated Brillouin scattering offers a broad range of applications, including lasers, sensors, and microwave photonics, most of which require strong Brillouin gain within a narrow bandwidth. Here, we experimentally report the first measurement of stimulated Brillouin scattering in silica optical nanofibers from both hybrid and surface acoustic waves. Using a pump–probe technique in the radio frequency domain, we measured a Brillouin gain as high as 15 m−1 W−1 and linewidth to 16 MHz for the L03 hybrid acoustic mode near 9 GHz using a 990-nm diameter nanofiber. This gain is 65 times larger than the highest gain obtained in standard single-mode fibers. In addition, we report a Brillouin gain of up to 5 m−1 W−1 from surface acoustic waves around 5 GHz. We further demonstrate a nanofiber-based Brillouin laser with a threshold of 350 mW. Our results create opportunities for advanced Brillouin-based applications utilizing optical nanofibers. [ABSTRACT FROM AUTHOR]

We present here an experimental demonstration of dual-comb spectroscopy performed around 2 µm, with the use of a new design of dispersion-controlled highly nonlinear fibre. The latter allows us to efficiently convert light via a four-wave mixing process from 1.55 µm to 2 µm, which is a spectral region suited for the detection of pollutants such as CO2 or N2O. Experimental measurements have been performed with these two molecules and show an excellent agreement with the HITRAN database.

We investigate coherent Kerr combs generation via Brillouin lasing in a non-reciprocal cavity. This approach offers adjustable repetition rates and enhanced coherence. A numerical model is presented that ac-counts for the interplay between Brillouin scattering, Kerr effect, and cavity resonant feedback. Through quan-titative agreement with experiments, our study highlights the importance of mode-pulling effects in setting the comb’s dynamics, which had been overlooked in previous fiber experiments. Finally, we discuss limitations and suggest scaling laws for these systems.

We demonstrate an athermal Brillouin strain sensor using heavily GeO2-doped optical fibers. We also report nonlinear evolution of Brillouin temperature sensitivity as a function of wavelength and strong Brillouin gain in these fibers.

We report on a stabilized single-frequency Brillouin fiber laser operating at 1.06 µm by means of a passive highly nonlinear fiber ring cavity combined with a phase-locking loop scheme. We show significant linewidth narrowing (below 1-kHz) as well as frequency noise reduction compared to that of the initial pump in our mode-hop free Brillouin fiber laser.

Among the different fundamental aspects that govern the design and development of elongated multimaterial structures via the preform-to-fiber technique, material association methodologies hold a crucial role. They greatly impact the number, complexity and possible combinations of functions that can be integrated within single fibers, thus defining their applicability. In this work, co-drawing strategies to produce monofilament microfibers from unique glass-polymer associations are discussed.

We investigate the spectral phase characteristics of dual-pumped Kerr frequency combs generated in a bichromatic Brillouin fiber laser architecture with normal dispersion, producing square-like pulse profiles. Using a pulse shaper, we measure the relative phase between the pump Stokes and adjacent lines, revealing a symmetric phase relationship. Our results highlight good phase coherence of the comb. By manipulating spectral amplitudes and phases, we demonstrate the transformation into various optical waveforms. The stability of our low-noise frequency comb ensures reliable performance in practical settings.