Photonic wire fabrication in bulk lithium niobate

Abstract

This project is to fabricate a photonic wire in bulk lithium niobate. Photonic wire fabricated by lithium niobate thin film on silicon dioxide wafer is a high performance waveguide. However, the price of it is few hundred times more than the photonic wire in bulk lithium niobate. Therefore, in this project, photonic wire in bulk lithium niobate which is cheaper is fabricated and is tested to find out its performance on guiding lights and check whether it can be used to replace lithium niobate thin film on silicon dioxide when the budget is limited. Proton exchange, annealing and RIE are used to increase the refractive index of the lithium niobate, change its graded-index to step-index and fabricate its shape respectively. The refractive index is increased by 0.09 at 632.8nm wave length and 0.08 at 1.55μm wavelength. The results show that both visible light and infrared can be guided by the photonic wire in bulk lithium niobate. Therefore, this photonic wire can be used as a cheaper replacement when budget is limited.