title: Nonlinear optical waveguides generated in lithium niobate by swift-ion irradiation at ultralow fluences.
abstract: A novel method to produce optical waveguides is demonstrated for lithium niobate (LiNbO(3)). It is based on electronic excitation damage by swift ions, i.e., with energies at approximately 1 MeV/amu or above. The new technique uses high-energy medium-mass ions, such as Cl, with electronic stopping powers above the threshold value for amorphization (5-6 keV/nm), reaching the maximum value a few micrometers inside the crystal. At the ultralow fluence regime (10(12)-10(13) cm(-2)) an effective nanostructured medium is obtained that behaves as an optical waveguide where light propagates transversally to the amorphous nanotracks created by every single impact. The method implies a reduction of 4 orders of magnitude with respect to He implantation. The optical waveguides present reasonable losses (~10 dB/cm) and significant second-harmonic generation (SHG) and electro-optic (EO) responses (>50% bulk) for the lowest fluences.
authors.affiliation: 1Instituto de Optica Daza de Valdés, CSIC, C/Serrano 121, 28006-Madrid, Spain. j.olivares@io.cfmac.csic.es
authors.forename: J
authors.initials: J
authors.lastname: Olivares
authors.forename: A
authors.initials: A
authors.lastname: García-Navarro
authors.forename: G
authors.initials: G
authors.lastname: García
authors.forename: A
authors.initials: A
authors.lastname: Méndez
authors.forename: F
authors.initials: F
authors.lastname: Agulló-López
authors.forename: A
authors.initials: A
authors.lastname: García-Cabañes
authors.forename: M
authors.initials: M
authors.lastname: Carrascosa
authors.forename: O
authors.initials: O
authors.lastname: Caballero