Ridge waveguides in lithium niobate as an integration platform for efficient laser and nonlinear optics applications
Final Report Abstract
In this project, we explored a new platform for ridge waveguides in lithium niobate based on a new method of optical-grade dicing and in-diffusion from three sides of the ridges. These waveguides promise attractive applications for the development of active devices and for use in nonlinear frequency conversion. Different dopants including Er, Nd, Yb, Pr, Dy, Th and Ho were used for the development of active devices, while Ti was in-diffused to form optical waveguides. Due to high-temperature annealing, very smooth surfaces were realized, allowing for low optical damping of about 0.1 dB/cm. We showed that optical gain, e.g. at 1531 nm wavelength for Er-doped waveguides, can be increased to 3.2 dB/cm, much higher than the best values of 2 dB/cm reported in the literature for channel waveguides. Continuous wave operation was achieved for Er, Nd and also Yb ridge waveguide lasers, with rather high slope efficiencies. By performing post-annealing electric-field assisted periodic poling of Ti-diffused ridge waveguides, high-efficiency quasi-phase matched nonlinear wavelength conversion has been demonstrated, too. Photorefractive effects that may degrade the optical performance of lithium niobate waveguides when pumped at high power in the visible or near infrared were strongly reduced by an additional thin ITO coating across the ridge waveguides.
Publications
- Er:Ti:LiNbO3 ridge waveguides amplifiers by optical grade dicing and three-side Er/Ti in-diffusion, Conf. Europhoton 2016, Vienna, Austria (2016)
S. Suntsov, C. E. Rüter, D. Kip
- Efficient ridge waveguide amplifiers and lasers in Er-doped lithium niobate by optical grade dicing and three-side Er and Ti indiffusion, Opt. Express 25, 29374 (2017)
D. Brüske, S. Suntsov, C. E. Rüter, D. Kip
(See online at https://doi.org/10.1364/OE.25.029374) - Er:Ti:LiNbO3 ridge waveguide optical amplifiers by optical grade dicing and three-side Er and Ti in-diffusion, Appl. Phys. B 123, 118 (2017)
S. Suntsov, C. E. Rüter, D. Kip
(See online at https://doi.org/10.1007/s00340-016-6635-1) - Efficient Ti:LiNbO3 ridge waveguide lasers: investigation of Er and Yb:Er doped waveguides pumped at 980 nm and 1486 nm, Proc. SPIE 10511: Solid State Lasers XXVII: Technology and Devices (March 2018)
D. Brüske, S. Suntsov, M. F. Volk, C. E. Rüter, D. Kip
(See online at https://doi.org/10.1117/12.2289980) - Efficient Nd:Ti:LiNbO3 ridge waveguide lasers emitting around 1085 nm, Opt. Express 27, 8884 (2019)
D. Brüske, S. Suntsov, C. E. Rüter, D. Kip
(See online at https://doi.org/10.1364/OE.27.008884) - “Efficient Er and Nd:Ti:LiNbO3 ridge waveguide lasers for the development of mid infrared sources,” in 2019 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, OSA Technical Digest (Optical Society of America, 2019), paper cj_p_32
D. Brüske, S. Suntsov, C. E. Rüter, and D. Kip
(See online at https://doi.org/10.1109/CLEOE-EQEC.2019.8872609) - Investigation of ytterbium incorporation in lithium niobate for active waveguide devices, Appl. Sci. 10, 2189 (2020)
C. E. Rüter, D. Brüske, S. Suntsov, D. Kip
(See online at https://doi.org/10.3390/app10062189)
