Femtosecond laser inscription of nonlinear photonic circuits in Gallium Lanthanum Sulphide glass. (6th December 2018)

• Record Type: Journal Article
• Authors: Vázquez, María Ramos; Sotillo, Belén; Rampini, Stefano; Bharadwaj, Vibhav; Gholipour, Behrad; Fernández, Paloma; Ramponi, Roberta; Soci, Cesare; Eaton, Shane M
• Is Part Of: JPhys photonics. Volume 1:Number 1(2019)
• Publication Date: 2018-12-06
• Subjects: ultrafast laser writing -- chalcogenide glass -- optical switching; Photonics -- Periodicals; 621.365
• DOI: 10.1088/2515-7647/aade60
• Languages: English
• ISSNs: 2515-7647

Abstract

Abstract: We report on femtosecond laser writing of single mode optical waveguides in chalcogenide Gallium Lanthanum Sulphide (GLS) glass. A multiscan fabrication process was employed to create waveguides with symmetric single mode guidance and low insertion losses for the first time at 800 nm wavelength, compatible with Ti:Sapphire ultrafast lasers and nonlinear photonics applications. μ Raman and x-ray microanalysis were used to elucidate the origin of the laser-induced refractive index change in GLS. We found that the laser irradiation produced a gentle modification of the GLS network, altering the Ga–S and La–S bonds to induce an increase in the refractive index. Nonlinear refractive index measurements of the waveguides were performed by finding the optical switching parameters of a directional coupler, demonstrating that the nonlinear properties were preserved, evidencing that GLS is a promising platform for laser-written integrated nonlinear photonics.