Author, as appears in the article.: Magdalena Aguiló; Muhammad Ali Butt; Huu-Dat Nguyen; Airán Ródenas; Carolina Romero; Pablo Moreno; Javier R. Vázquez de Aldana; Rosa Maria Solé; Maria Cinta Pujol; Francesc Díaz
Department: Química Física i Inorgànica
URV's Author/s: AGUILÓ DÍAZ, MAGDALENA; Muhammad Ali Butt; Huu-Dat Nguyen; Airán Ródenas; Carolina Romero; Pablo Moreno; Javier R. Vázquez de Aldana; SOLÉ CARTAÑÀ, ROSA MARIA; PUJOL BAIGES, MARIA CINTA; DÍAZ GONZÁLEZ, FRANCISCO MANUEL
Abstract: We report on the direct low-repetition rate femtosecond pulse laser microfabrication of optical waveguides in KTP crystals and the characterization of refractive index changes after the thermal annealing of the sample, with the focus on studying the potential for direct laser fabricating Mach-Zehnder optical modulators. We have fabricated square cladding waveguides by means of stacking damage tracks, and found that the refractive index decrease is large for vertically polarized light (c-axis; TM polarized) but rather weak for horizontally polarized light (a-axis; TE polarized), this leading to good near-infrared light confinement for TM modes but poor for TE modes. However, after performing a sample thermal annealing we have found that the thermal process enables a refractive index increment of around 1.5x10−3 for TE polarized light, while maintaining the negative index change of around −1x10−2 for TM polarized light. In order to evaluate the local refractive index changes we have followed a multistep procedure: We have first characterized the waveguide cross-sections by means of Raman micro-mapping to access the lattice micro-modifications and their spatial extent. Secondly we have modeled the waveguides following the modified region sizes obtained by micro-Raman with finite element method software to obtain a best match between the experimental propagation modes and the simulated ones. Furthermore we also report the fabrication of Mach-Zehnder structures and the evaluation of propagation losses.
Research group: Física i Cristal.lografia de Materials Física i Cristal·lografia de Nanomaterials
Thematic Areas: Química Química Chemistry
licence for use: https://creativecommons.org/licenses/by/3.0/es/
ISSN: 1094-4087
Author identifier: 0000-0001-6130-9579; ; ; ; ; ; ; 0000-0002-5769-4141; 0000-0002-1052-8031; 0000-0003-4581-4967
Record's date: 2017-05-25
Last page: 15355
Journal volume: 23
Papper version: info:eu-repo/semantics/publishedVersion
Link to the original source: https://www.osapublishing.org/oe/abstract.cfm?uri=oe-23-12-15343
Funding program: plan; Retas/FIS; FIS2013-44174-P;MAT2013-47395-C4-4-R;TEC2014-55948-R
Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
Article's DOI: 10.1364/OE.23.015343
Entity: Universitat Rovira i Virgili
Journal publication year: 2016
First page: 15343
Publication Type: Article Artículo Article
Repositori URV