Applied Surface Science 307 (2014) 645–653 Contents lists available at ScienceDirect Applied Surface Science jou rn al h om ep age: www.elsevier.com/locate/apsusc Microstructure of planar glass substrates modified by Laser Ablation Backwriting (LAB) of metal targets F. Rey-García a,b , M.T. Flores-Arias a , C. Gómez-Reino a , R. Lahoz b , G.F. de la Fuente b,∗ , W. Assenmacher c , W. Mader c a UA Microóptica & Óptica GRIN, Departamento de Física Aplicada, Facultade de Óptica e Optometría, Universidade de Santiago de Compostela, Campus Vida s/n, E-15782 Santiago de Compostela, Spain b Instituto de Ciencia de Materiales de Aragón (CSIC-Universidad de Zaragoza), María de Luna 3, E-50018 Zaragoza, Spain c Institut für Anorganische Chemie, Universität Bonn, Romerstraˇe 164, D-53117 Bonn, Germany a r t i c l e i n f o Article history: Received 2 January 2014 Received in revised form 17 March 2014 Accepted 12 April 2014 Available online 23 April 2014 Keywords: Microstructure Soda lime glass waveguide Laser ablation Ag Al Brass a b s t r a c t Geometrically controlled, channel-like structures were prepared on commercial, soda-lime glass sub- strates, by a Laser Ablation Backwriting (LAB) process using a commercial Nd:YVO 4 laser fitted with a beam steering galvanometer mirror unit. 70Cu30Zn Brass alloy, Ag and Al metal targets were evaporated onto glass substrates by simple irradiation through the same glass substrates. The resultant structures were characterized by SEM, TEM, and UV-vis-nIR spectroscopy. These revealed the presence of metal nanostructures in the case of brass and Ag targets, with their typical local surface plasmon resonance (LSPR) bands. In contrast, Al was not found in its elemental form, but rather integrated into the glass substrate. These results were confirmed by energy dispersive X-ray microanalysis (EDS) studies, per- formed with TEM and SEM observation on representative, polished cross section samples. Preliminary light guiding studies demonstrated the potential to develop burried waveguides just below the surface of the glass substrates in all cases, suggesting that LAB may be a convenient method to prepare stable waveguides by modifying inexpensive, commercial window glass. © 2014 Elsevier B.V. All rights reserved. 1. Introduction The advantages of planar glass waveguides and their prepara- tion via Laser Ablation Backwriting (LAB, also known as LIRT – laser induced reverse transfer) of metal targets have been extensively discussed in the recent literature [1–4]. In addition, LAB has also been applied to the successful fabrication of optical phase diffrac- tion gratings [5] and may be considered as a convenient method for the preparation of elements useful in a number of attractive optical devices. An important aspect to consider in LAB of metals deposited onto glass substrates, relates to the nature of the metal species evolving from the target during the ablation process. Although nanosecond (ns) laser irradiation has been commonly used initially for metal ablation [1–6 and references therein], and it is used in advanced manufacturing processes, the most recent literature reports mainly on work performed on metals with ultrashort pulsed lasers, within ∗ Corresponding author. Tel.: +34 976762527; fax: +34 976761957. E-mail addresses: xerman@unizar.es, german.delafuente.leis@csic.es (G.F. de la Fuente). the picosecond (ps) [6,7] and femtosecond (fs) [8] regimes. Ref. [6] provides an overview of laser ablation phenomena and a timely comparison of processes carried out within the ns, ps and fs regimes. More particular characteristics of ultrashort pulse laser ablation of metals, within the ps regime, are reviewed for metal ablation efficiency in [7]. Chakravarty et al. reported on a compar- ison of ps and fs metal ablation in the context of nanoparticle size control as a function of pulse length [8]. An important disadvantage of ultrashort pulse lasers, however, is their high cost and limited productivity. Pulsed ns lasers have thus been chosen for this study because they still offer many advantages from the practical point of view, particularly when considering their application to materials fabrication processes at the industrial scale. In contrast to laser processing, alternative methods for the preparation of waveguides on glass have been extensively stud- ied and reviewed recently [9–11]. Although these include high throughput methods, such as sol–gel dip coating, they usually lack the desired geometrical flexibility and require the use of solvents. For these reasons, and because they require multiple preparative steps which make them less environmentally attractive and at times more costly, the LAB process has been explored recently as http://dx.doi.org/10.1016/j.apsusc.2014.04.091 0169-4332/© 2014 Elsevier B.V. All rights reserved.