1. Kevin Bourhis Jean-Jacques Videau, Mona Treguer, Thierry Cardinal (ICMCB-CNRS) Arnaud Royon, Lionel Canioni (CPMOH-CNRS) Workshop LasINOF, June 14 th 2010

2. Interaction between short-pulsed lasers and silver-containing glasses  micro- and nanostructuring in 3D can be achieved Glass modification visible under UV (325 nm) or blue light (405 nm) Stability of the photo-induced structures variable (composition, irradiation conditions…) Examples of stability of photo-induced structuring with femtosecond lasers  Femtosecond laser irradiation = silver reduction + heat treatment  What affects the stability ? - silver content - the glassy matrix - the irradiation conditions

3. 1.Silver and gallium introduction 2.Nature and modifications of the glassy matrix 3.Influence of the irradiation conditions 4.Conclusion

4. Red shift of the absorption cut-off (5d 10  4d 9 5s 1 dipolar transition Ag + ion) with increasing Ag/Ga 1 to 4 mol%(Ag 2 O) = [Ag/Ga] x 16 55ZnO-4OP 2 O 5 Good system for Ag + introduction Hygroscopic glass  addition of Ga (reticulation), conservation of P/Zn ratio Glass composition studied : 55 ZnO – 40 P 2 O 5 – (5-x) Ag 2 O – x Ga 2 O 3, x ? IR-fs structures  µm 3  UV-ns structures = near-band gap, larger areas

5. PHOTOSENSITIVE AGENT Ag + ion Photoreduction (photographic process)  Formation of Ag m x+ clusters Luminescent probe  Ag m x+ clusters Irradiation at laser = 355 nm Growth of absorption bands @ 320 nm @ 380 nm  New Ag m x+ species are formed during the irradiation  Luminescence spectra = evidences of modifications

6. Red shift of the excitation band (   15 nm) with Ag/Ga Ag/Ga Number of sites max (nm) 1/42290 ; 385 41385 Modification of the glassy network Neighboring of the non-bridging O linked with P or Ga to be investigated

7. 55ZnO-40P 2 O 5 Majority of Q 2 and Q 1 sites (1 or 2 NBO) Q n, n = number of bridging O  s & as (P-O-P), Q 2 & Q 1 705 cm -1 =  (P-O-P) of Q 2 750 cm -1 =  (P-O-P) of Q 1 Ag/Ga decreases  Q 1 /Q 2 increases Hypothesis : Ag + localized on Q 1 sites (chains end) Number of Q 1 stable Ga addtion  depolymerisation of Q 2 sites Q 2 + Ga 2 O 3  2Q 1 Q 2 = [PO4] polyhedra (long chain) Q 1 = [PO4] terminal tetrahedra

8. Emission @ exc = 250 nm Emission @ exc = 325 nm; excitation @ 600 nm For both glasses, decrease of the « Ag + » 365 nm band Ag-poor glass : no effect on the 280 nm band After irradiation, same spectra obtained Useless to lower the Ag/Ga ratio (2 sites, 1 ineffective, similar emission results) Ag m x+ spectra« Isolated » Ag + spectra

9. Saturation phenomenon, similar to photographic process Consumption of the silver ions pool ? Ag + + h   Ag 0 Ag + + Ag 0  Ag 2 + Ag 2 + + Ag +  Ag 3 2+ … Ag m x+

10. EPR : collaboration with D. Caurant & L. Binet (ENSCP, Paris) Ag 2+ paramagnetic centers identified g ortho = 2.307 g // = 2.072 Triangular Ag 3 2+ signature ? gi so = 2.003 Seems to be a good tool for determining the Ag m x+ paramagnetic species Concentration of species relatively low, behavior of this species with T ?

11. Heat treatment : Elimination of the 380 nm excitation band Blue shifting of the emission Low dosage with fs laser  similar to ns : no heat accumulation effect High dosage with fs laser : blue shifting of the luminescence to orange Controlling the dose and the temperature  tailoring of the luminescence

12. Effects of the silver introduction investigated : characterization of 2 luminescent sites Effect of the gallium on the glass network discussed : Depolymerization of the network while increasing the gallium content Comparisons with thermally treated and fs irradiated samples done : fs irradiation = combination of athermal processes and temperature