Laser structuration of dielectric materials by a train of femtosecond pulses through cumulative effects

E Smetanina (1) , O Caulier (1) , B Chimier (1) , Stefan Skupin (1) , A Bourgeade (2) , K Mishchik (1) , J Lopez (1) , C Javaux Léger (3) , C Hoenninger (4) , R Kling (3) , Y Petit (5) , T Cardinal (5) , L Canioni (1) , V Tikhonchuk (1) , G Duchateau (1)

1 CELIA - Centre d'Etudes Lasers Intenses et Applications
2 CESTA - Centre d'études scientifiques et techniques d'Aquitaine
3 alphanov
4 Amplitude Systèmes
5 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Optical materials can be structured by laser pulses to get new material functionalities in various scientific area going from photonics to medicine. For instance, wave guides, nano-gratings, emergence of nonlinear optical properties for data storage [1], cutting and welding of materials are applications of great interest. Structuration driven by a train of laser pulses is strongly emerging due to its advantages: table top laser facility, very well controlled structuration with energy deposition accuracy in the nJ range by adjusting the number of pulses, etc. The material structuration due to pulse-to-pulse cumulative effects should be deeply understood to design specific structures. This may be achieved by modelling the main physical processes and their possible coupling. Briefly, each laser pulse first induces photo-ionization and heats the conduction electrons which can then transfer their energy to the lattice. That leads to a local increase in the material temperature together with heat diffusion and thermally-activated ions migration on longer timescales. Since the laser pulse is partially absorbed, the electron dynamics and the pulse propagation are closely coupled. Due to the low heat diffusion coefficient of dielectric materials, the laser energy may be accumulated in the absorption region, leading to high temperatures even if the single pulse energy is too low to induce itself any significant material modification. A general modelling including all the above-mentioned processes will be presented, including the two following applications of interest.

Domaines: Optique [physics.optics]; Physique Atomique [physics.atom-ph]; Physique des plasmas [physics.plasm-ph]

E Smetanina, O Caulier, B Chimier, Stefan Skupin, A Bourgeade, et al.. Laser structuration of dielectric materials by a train of femtosecond pulses through cumulative effects. COLA 2015, Aug 2015, Cairns, Australia. ⟨hal-01199899⟩