Optical waveguides and devices in glass materials

Abstract

The project is going to design and fabricate a lithium niobate micro-ring resonator, with a high-Q value, to minimise the propagation loss. For the material LN(Lithium Niobate), which was widely used in so many ways, as it offers a useful platform for converting the wavelength, and provide communication in high speed, microwave photonics, it was mainly used as piezoelectric sensors, optical modulators. Ordinary optical waveguide was defined by ion diffusion and proton exchange methods, and resulting in a contrast with low index, and optical confinement is relatively weak. By using the model of integrated LN(Lithium Niobate), which enabling the light confinement of subwavelength and denser electrical and optical components integration, with the use of such characteristics, so that the optical communication could be revolutionize into a higher level. On the contrary, there must be some difficulties in the process of fabrication. It would be a challenge when we want to approach both low level of optical propagation loss and achieving high confinement of wave. So, the solution was divided into two approaches, which were hybrid and monolithic. For the hybrid solution, it is going to integrate the thin film Lithium Niobate and the Silicon(S)/ Silicon Nitride(S3N) (easy-to -etch material) in order to achieve a low value of propagation loss(~0.3dBcm-1), but it causes the optical mode only partially operating in active region, so the other approach is monolithic approach, which is directly etch of LN in order to meet a high level of optical confinement, but it still cause a certain level of propagation loss. By implement these two categories together, to increase the ability of optical confinement and low propagation loss at the same time. So, in the final report, I am going to describe the fabrication process and its structure, use the collected data to describe a quality of a waveguide and its outcome and tell what is a good waveguide be like, the fundamental principle of the micro ring resonator, the difficulties encountered and finally summarize the project.