2024-03-28T12:00:13Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/653932021-06-07T13:05:18Zcom_10261_93com_10261_4col_10261_346
Correlation of the refractive index change at the surface and inside phosphate glass upon femtosecond laser irradiation
Puerto, D.
Siegel, Jan
Ferrer, Andrés
Hernández Rueda, Javier
Solís Céspedes, Javier
A study of the surface modification induced by single femtosecond laser pulses in phosphate glass has revealed surface swelling at fluences just below the ablation threshold. This behavior is different from that observed in other dielectric materials. Optical micrographs obtained with monochromatic light show a pattern of Newton rings within the swollen region whose number scales inversely with the illumination wavelength, acting as a micro Fabry-Perot etalon. The swollen surface layer has lower refractive index than the bulk glass and can reach a maximum thickness of 820 nm. We relate these findings to results obtained during subsurface waveguide writing inside phosphate glass, which also show a refractive index decrease at energies near threshold for waveguide fabrication. We have identified low density free-electron plasma to be the trigger of the refractive index change. © 2012 Optical Society of America.
This work has been partially supported by the Spanish TEC 2008- 01183 and TEC2011-22422. D. Puerto acknowledges his grant of the Spanish Ministry of Science and Education under TEC 2005-0007 and JCI-2010-07479.
Peer Reviewed
2013-01-29T11:39:38Z
2013-01-29T11:39:38Z
2012
2013-01-29T11:39:38Z
artículo
http://purl.org/coar/resource_type/c_6501
doi: 10.1364/JOSAB.29.002665
issn: 0740-3224
Journal of the Optical Society of America B: Optical Physics 29: 2665-2668 (2012)
http://hdl.handle.net/10261/65393
10.1364/JOSAB.29.002665
en
open
Optical Society of America