Two-photon Absorption measurements for Implanted Gold Nanoparticles in Silicate Glasses
A. Ajami a, W. Husinsky a, P. Nekvindova b, B. Svecova b, J. Pesickac and M. Janecekc
a Institute
of Applied Physics, Vienna University of Technology
Wiedner Huaptstrasse 8-10 Wien-1040, Austria
bDepartment
of Inorganic Chemistry, Faculty of Chemical Technology, Institute of Chemical
Technology, Technicka 5, 166 28 Prague, Czech Republic
cCharles
University, Faculty of Mathematics and Physics, Department of Physics of Materials,
Ke Karlovu 5, 121 16 Prague, Czech Republic
Ali_ajami80@yahoo.com
Abstract
Metal nano-clusters composite glasses synthesized by ion implantation have been shown as
promising nonlinear photonic material [1-3]. In this contribution we report on the two-photon absorption
(TPA) measurements of gold nano-particles implanted in four structurally different types of silicate
glasses. All targets, containing gold nano-particles in a layer 500 nm under the surface of the glass,
have been prepared by ion implantation with subsequent annealing. The targets were characterized
by transmission electron microscope (TEM) and by the Z-scan technique [4]. The resulting nanoparticles differed in size and shape as well as the depth distribution characteristic for glasses with
different chemical composition. The gold nanoparticles implanted in different glasses were produced
under the same conditions: beam energy of 1701 keV, ion fluence of 1×1016 ion.cm–2, postimplantation annealing in air at 600 °C for 5 hrs.
TPA coefficient was measured applying the open aperture Z-scan technique for ultrashort pulsed laser
radiation. A Ti:sapphire laser was used that delivers 25 fs pulses at a repetition rate of 1 kHz each
pulse having a maximum energy of 1 mJ with a spectrum centered at 798 nm [5]. A 175 mm focal
length lens was used to focus the 15 mm diameter laser beam within the sample.
The TPA coefficient was determined by fitting Eq. 1 to the Z-scan experimental data.
q0 n

T (z)  
n 0
n  1 2 1  x 2 
3
n
(1)
where q0 is βLI0, β is the TPA coefficient, L is the thickness of sample (gold nano-particles layer),
x=z/z0, z is the sample position, z0 is the Rayleigh range and I0 is the maximum on-axis intensity at the
focal point of the laser beam within the sample.
It was proven that the presence of gold nanoparticles causes the enhancement of the nonlinear optical
absorption of the glass. The highest TPA coefficient of 16.25 cm/GW was obtained for as-anealed
BK7 that had developed the largest non-spherical nanoparticles in the thinnest layer of 100 nm.
Table. 1. TPA coefficient for gold nanoparticles implanted in different type of silicate glasses
Glass substrate
Silica glass Glass B GIL 49 BK 7
TPA coefficient (cm/GW) 2.46
5.21
1
7.75
16.25
References
[1] P. C. S. Kasap, Springer Handbook of Electronic and Photonic Materials, Springer,New York,
2006.
[2] F. Gonella and P. Mazzoldi, Handbook of Nanostructured Materials and Nanotechnology,
Academic,4, San Diego, 2000.
[3] A. I. Ryasnyanskiy, B. Palpant, S. Debrus, U. Pal and A. L. Stepanov, Physics of the Solid State.
51 (2009) 55.
[4] M. Sheik-Bahae, A. A. Said, T.-H. Wei, D. J. Hagan and E. W. Van Stryland, IEEE Journal of
Quantum Electronics. 26 (1990) 760.
[5] A. Ajami, W. Husinsky, R. Liska and N. Pucher, Journal of the Optical Society of America B:
Optical Physics. 27 (2010) 2290.
Fig. 1. Z-scans of the as-annealed glass BK7 containing gold nanoparticles for different pulse energies
(a) Glass BK7
(b) Glass B
Fig. 2. TEM images of gold nanoparticles implanted in glass BK7 (a) and in glass B (b)
2