Clean waveguides in lithium niobate thin film formed by He ion implantation

• Published in: Applied physics. B, Lasers and optics Lasers and optics, 2017-08, Vol.123 (8), p.1-5, Article 220
• Main Authors: Zhang, Shao-Mei, Jiang, Yun-Peng, Jiao, Yang
• Format: Article
• Language: English
• Subjects: Applied physics; Chemical bonds; Clean energy; Energy consumption; Engineering; Ion implantation; Lasers; Lithium; Mathematical analysis; Optical Devices; Optical properties; Optics; Photonics; Physical Chemistry; Physics; Physics and Astronomy; Planar waveguides; Quantum Optics; Refractivity; Silicon dioxide; Single crystals; Thin films; Wave propagation
• ISSN: 0946-2171; 1432-0649
• DOI: 10.1007/s00340-017-6797-5

We report on the fabrication of channel waveguides by He ion implantation in a single-crystal LiNbO 3 film bonded to a SiO 2 /LiNbO 3 substrate. The planar waveguides were also formed under the same conditions to show the refractive index changes and the thermal annealing properties of ion-implanted LiNbO 3 thin film. Using a moderate implantation energy, the formed channel waveguides were clean because He ions passed through the LiNbO 3 thin film and deposited into the SiO 2 layer. The optical propagation properties of channel waveguides were measured using an end-face coupling method, and the theoretical results were simultaneously calculated for comparison. The mode sizes and end-face reflectivities of channel waveguides with different widths were numerically calculated. The propagation losses were also estimated at approximately 12.2 and 14.3 dB/cm for 7 μm- and 5 μm-wide waveguides, respectively, by the Fabry–Perot method.