Highly Confining Proton Exchanged Waveguides on Z-Cut LiNbO3 With Preserved Nonlinear Coefficient

• Published in: IEEE photonics technology letters Vol. 26; no. 15; pp. 1557 - 1560
• Main Authors: Stepanenko, Oleksandr, Quillier, Emmanuel, Tronche, Herve, Baldi, Pascal, De Micheli, Marc
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.08.2014; The Institute of Electrical and Electronics Engineers, Inc. (IEEE); Institute of Electrical and Electronics Engineers
• Subjects: Indexes; Lithium niobate; Nonlinear optics; Optical device fabrication; Optical waveguides; Optics; Physics; Protons; nonlinear optics; optical planar waveguides; fabrication; Dielectric waveguides; lithium compounds •optical fabrication •optical harmonic generation •optical planar waveguides
• ISSN: 1041-1135; 1941-0174
• DOI: 10.1109/LPT.2014.2329134

We propose a new proton exchange process to reproducibly realize on lithium niobate highly confining (δn e = 0.1) planar waveguides without degrading the nonlinear coefficient of the crystal. Waveguides were fabricated with different acidic baths and the crystallographic changes, the index profiles and the local SHG response were measured. We show that for certain fabrication conditions, characteristic of the so-called high-index soft proton exchange process, the high-index modification can be obtained without degrading the crystal nonlinear coefficient. This result should open the way to the fabrication of very efficient nonlinear devices.