Author, as appears in the article.: Airán Ródenas; Huu-Dat Nguyen; Javier R. Vázquez de Aldana; Javier Martínez; Feng Chen; Magdalena Aguiló; Maria Cinta Pujol; Francesc Díaz
Department: Química Física i Inorgànica
URV's Author/s: RODENAS SEGUI, AIRAN; Huu-Dat Nguyen; Javier R. Vázquez de Aldana; Javier Martínez; Feng Chen; AGUILÓ DÍAZ, MAGDALENA; PUJOL BAIGES, MARIA CINTA; DÍAZ GONZÁLEZ, FRANCISCO MANUEL
Keywords: Està en blanc
Abstract: Mid-infrared lithium niobate cladding waveguides have great potential in low-loss on-chip non-linear optical instruments such as midinfrared spectrometers and frequency converters, but their threedimensional femtosecond-laser fabrication is currently not well understood due to the complex interplay between achievable depressed index values and the stress-optic refractive index changes arising as a function of both laser fabrication parameters, and cladding arrangement. Moreover, both the stress-field anisotropy and the asymmetric shape of low-index tracks yield highly birefringent waveguides not useful for most applications where controlling and manipulating the polarization state of a light beam is crucial. To achieve true high performance devices a fundamental understanding on how these waveguides behave and how they can be ultimately optimized is required. In this work we employ a heuristic modelling approach based on the use of standard optical characterization data along with standard computational numerical methods to obtain a satisfactory approximate solution to the problem of designing realistic laserwritten circuit building-blocks, such as straight waveguides, bends and evanescent splitters. We infer basic waveguide design parameters such as the complex index of refraction of laser-written tracks at 3.68 μm midinfrared wavelengths, as well as the cross-sectional stress-optic index maps, obtaining an overall waveguide simulation that closely matches the measured mid-infrared waveguide properties in terms of anisotropy, mode field distributions and propagation losses. We then explore experimentally feasible waveguide designs in the search of a single-mode low-loss behaviour for both ordinary and extraordinary polarizations. We evaluate the overall losses of s-bend components unveiling the expected radiation bend losses of this type of waveguides, and finally showcase a prototype design of a low-loss evanescent splitter. Developing a realistic waveguide model with which robust waveguide designs can be developed will be key for exploiting the potential of the technology.
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: n/a; n/a; 0000-0002-5264-8525; n/a; n/a; 0000-0001-6130-9579; 0000-0002-1052-8031; 0000-0003-4581-4967
Record's date: 2016-05-18
Last page: 7791
Journal volume: 24
Papper version: info:eu-repo/semantics/publishedVersion
Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
Entity: Universitat Rovira i Virgili
Journal publication year: 2016
First page: 7777
Publication Type: Article Artículo Article
Repositori URV