Two-photon excited fluorescence in the LYB:Eu monoclinic crystal: towards a new scheme of single-beam dual-voxel direct laser writing in crystals

Yannick Petit (1, 2) , Arnaud Royon (1) , Nicolas Marquestaut (1) , Marc Dussauze (3) , Alexandre Fargues (2) , Philippe Veber (2) , Veronique Jubera (2) , Thierry Cardinal (2) , Lionel Canioni (1)

1 LOMA - Laboratoire Ondes et Matière d'Aquitaine
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
3 ISM - Institut des Sciences Moléculaires

We report on two-photon excited fluorescence in the oriented Eu3+-doped LYB monoclinic crystal under femtosecond laser tight focusing. Due to spatial walk-off, the two polarization modes of the incident femtosecond beam simultaneously provide the independent excitation of two distinct focuses, leading to a single-beam dual-voxel nonlinear excitation of fluorescence below material modification threshold. These observations emphasize on the anisotropy of both two-photon absorption as well as fluorescence emission. They demonstrate the localized control of the nonlinear energy deposit, thanks to the adjustment of both the input power and polarization, by properly balancing the injected energy in each voxel. Such approach should be considered for future direct laser writing of waveguides in propagation directions out of the dielectric axes, so as to optimally cope with the highly probable anisotropy of laser-induced material modification thresholds in these crystals. These results open new ways for further potential developments in direct laser writing as the simultaneous inscription of double-line structures for original waveguides processes.

Mots clés: (160.1190) Anisotropic optical materials; (260.1180) Crystal optics; (260.1440) Birefringence; (270.4180) Multiphoton processes; (300.2530) Fluorescence; laser-induced; (260.5430) Polarization; (230.7370) Waveguides; (050.6875) Three-dimensional fabrication.; (050.6875) Three-dimensional fabrication

Domaines: Optique [physics.optics]

Yannick Petit, Arnaud Royon, Nicolas Marquestaut, Marc Dussauze, Alexandre Fargues, et al.. Two-photon excited fluorescence in the LYB:Eu monoclinic crystal: towards a new scheme of single-beam dual-voxel direct laser writing in crystals. Optics Express, 2013, 21 (1), pp.822-833. ⟨10.1364/OE.21.000822⟩. ⟨hal-00780614⟩