Origin of the refractive-index increase in laser-written waveguides in glasses

Journal Article · Sat Mar 15 04:00:00 EDT 2008 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2888561· OSTI ID:21133993

Ponader, Carl W; Schroeder, Joseph F; Streltsov, Alexander M ^[1]

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1. Corning Inc., Corning, New York 14831 (United States)

We present firm evidence that the mechanism for the refractive-index increase in fused silica caused by irradiation with ultrafast intense laser pulses is the densification of glass. This conclusion is based on the correlation observed between the refractive-index values in waveguides in silica produced by focused femtosecond laser pulses and the shift of the central frequency of {omega}{sub 4} (TO) band (Si-O stretching mode) in micro-Raman spectra. These data were compared with the relation of the Raman shift to density and to refractive index changes in glasses modified by high pressure or irradiation. We conclude that the measured refractive-index increase in silica waveguides can be explained by densification of glass and exclude other hypothesis such as fictive-temperature effect, color center formation, etc.

• OSTI ID: 21133993
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 6 Vol. 103; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COLOR CENTERS
GLASS
IRRADIATION
LASERS
PULSES
RAMAN SPECTRA
REFRACTIVE INDEX
SILICA
SPECTRAL SHIFT
WAVEGUIDES