Fabrication of Lithium Niobate Microring Devices using Ultrasound-aided-Etching

• Main Authors: Xiang-Nan Xiao, 蕭祥男
• Other Authors: 王子建
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/dpb8za

碩士 === 國立臺北科技大學 === 光電工程系研究所 === 99 === Currently, the main methods in fabrication of lithium niobate micro-ring resonators are crystal ion-slicing method, etching after ion implantation method, proton exchange after the wet etching, etc. In these methods, the former two need to use ion implantation and ion etching equipment, costly and complicated process. The latter with easily fabrication, relatively inexpensive, but requires two-step process, the process is more time-consuming. In this thesis, we claimed that by using ultrasound aided dilute HF etching, to fabricate the microring devices on z-surface of lithium niobate with high contrast of refraction index, the outside part of the waveguide to remove, so that waveguide direct contact with air, high optical confinement produced by transversal high refraction index contrast of ridge structure is utilized to reduce the propagation loss in the microring waveguide. This method provided a simple, low-cost, and time-saving way to manufacture the device. The comparison of surface roughness with traditional and ultrasound-assisted etching in this thesis, the results indicate that the ultrasound-assisted etching in 30V voltage, the lowest transmission loss waveguide was available. The fabrication of microring filters have a radius of 100μm and their coupler lengths are 0μm、40μm、80μm and 120μm, which is very close to the free spectral range and theoretical value.