Project Details
Projekt Print View

Ridge waveguides in lithium niobate as an integration platform for efficient laser and nonlinear optics applications

Subject Area Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
Term from 2016 to 2020
Project identifier Deutsche Forschungsgemeinschaft (DFG) - Project number 280878751
 
Final Report Year 2020

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

 
 

Additional Information

Textvergrößerung und Kontrastanpassung