Do not miss the following presentation on Monday 4, February 2019!
Processing with femtosecond lasers by using multi-plane light conversion beam shaping technique
Paper 10905-11 Time: 2:40 PM – 3:00 PM Author(s): Konstantin Mishchik, Eric Audouard, Eric Mottay, Clemens Hönninger, Amplitude Systèmes (France); Clément Jacquard, Lionel Garcia, Guillaume Labroille, Jean-François Morizur, Cailabs (France)
We demonstrate ultrafast laser processing with spatially shaped beams. Shaping is performed by multi-plane light conversion technology, where beam transformation is achieved by multi-reflections in a cavity with a reflective textured surface. This design helps to minimize losses, allows optimization for a large spectral bandwidth and is therefore compatible with high-power femtosecond laser sources. We characterize these elements using pulses as short as 150fs and average laser powers up to 100W to demonstrate patterning of thin foils and massive metals using squared flat-top and multibeams. Top-hat form reduces residual heat allowing accurate processing even at MHz-level laser repetition rates.
Turbulence-mitigating free-space-optical-communication receiver using multi-plane-light-conversion-based spatial mode demultiplexer
Paper 10910-12 Time: 2:10 PM – 2:30 PM Author(s): Bertrand Denolle, Gauthier Trunet, David Allioux, Pu Jian, Olivier Pinel, Guillaume Labroille, Cailabs (France)
In this work, we use a spatial mode demultiplexer based on Multi-Plane Light Conversion to implement a passive, spatial-diversity-based turbulence-mitigation technique for free space optical communication. As a turbulence-perturbed Gaussian beam can be decomposed on a few orthogonal spatial modes (3 to 15), we show that converting these spatial modes to single-mode fibers and then combining the detected signals enables to drastically increase the coupling efficiency under strong turbulence conditions and mitigate severe fading thanks to spatial-mode diversity.
Oral presentation of our partner Femto-st on february 5th
High aspect ratio nanochanneldrilling in glass byfemtosecond laser pulse ofhighcone angle, highqualityBessel-Gauss beam
Paper 10906-4 Time: 9:10 AM – 9:30 AM Author(s):Jesús DelHoyo, Institut Franche-Comte ElectroniqueMecanique Thermique et Optique (France); Pauline Boucher, Lab. KastlerBrossel (France), Cailabs (France); Cyril Billet, Institut Franche-Comte ElectroniqueMecanique Thermique et Optique (France); Olivier Pinel, Guillaume Labroille, Lab. KastlerBrossel (France), Sorbonne Univ. (France); François Courvoisier, Institut Franche-Comte ElectroniqueMecanique Thermique et Optique (France).
We address two important challenges in the field of ultrashort pulse shaping into Bessel beams for nanochannel drilling. First, high quality Bessel beams are essential for controlled energy deposition. Second, the maximal angle used up to here for channel drilling was 26 degrees. Here, we generate high quality Bessel-Gauss beams with a setup based on reflective, off-axis axicons. The cone angles are up to 35 degrees. This corresponds to central spot diameter down to 0.5 µm FWHM. We report femtosecond laser nanochannel drilling down to typically 100 nm over at least 30 µm length in glass.