All-Optical Characterization of Fs-Laser Induced Refractive Index Changes in Bulk and At the Surface of Zinc Phosphate Glasses

Abstract

The permanent refractive index change induced by ultrashort laser pulses in zinc phosphate glasses has been investigated both at the surface and in bulk. At the sample surface, irradiations have been performed by using loosely focused single fs-laser pulses at different energies. Optical microscopy images of the irradiations illustrate an interferometric pattern in form of concentric Newton rings due to the laser induced multilayer system (unmodified glass, thin laser-modified layer, air). This experimental reflectivity modulation along with simulations based on Abeles theory for multilayer optical systems allows retrieving laser-induced refractive index changes on the order of Δns= -10-3. In bulk, fs-laser written waveguides have been generated by translating the sample with respect to a tightly focused laser beam. The so-produced waveguides have been characterized by studying the optical near field of the TEM00 guided mode at 660 nm and using white light microscopy. The optical changes linked to the inscribed waveguides have been characterized by measuring the far field output profiles yielding values of approximately Δnb= +3·10-4. The laser-modified optical properties in bulk and at the surface will be linked to the glass structural changes as well as discussed in terms of the role of the incubation effects for multi-pulse processing.

Meeting Name

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XV (2015: Feb. 8-10, San Francisco, CA)

Department(s)

Materials Science and Engineering

Keywords and Phrases

Bulk; Femtosecond Laser; Newton Rings; Phosphate Glass; Refractive Index; Surface; Waveguides

International Standard Book Number (ISBN)

978-162841445-5

International Standard Serial Number (ISSN)

0277-786X; 1996-756X

Document Type

Article - Conference proceedings

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2015 SPIE, All rights reserved.

Publication Date

01 Feb 2015

Link to Full Text

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