Study of Electric-Field-Assisted Er diffusion in Lithium Niobate

• Main Authors: chen chiu-hui, 陳秋惠
• Other Authors: Tzyy-Jiann Wang
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/55942734945133506917

碩士 === 國立臺北科技大學 === 光電技術研究所 === 91 === Lithium niobate is a ferroelectric crystal and has excellent electrooptic, acoustooptic and nonlinear-optic properties. Because it cannot emit light directly, the LiNbO3 crystal needs to be doped with rare-earth element, such as erbium, to be used as gain material to produce optical amplifier or laser. The erbium-doping process in LiNbO3 includes: (1) deposition of erbium film on substrate surface and (2) diffusion at high temperature. Because the diffusion coefficient of erbium is small, its diffusion rate is low. Due to the slow diffusion of erbium in LiNbO3, diffusion depths on the order of a few micrometer require a diffusion temperatures of 1060-1100ºC and a diffusion time of several days. Hence, erbium diffusion process is very time-consuming, which easily degrades the properties of LiNbO3. In this thesis, electric-field-assisted diffusion method is proposed to accelerate the erbium diffusion rate in LiNbO3. The erbium distribution profiles under the electric field diffusion with various diffusion conditions are calculated and its effects on the characteristics of the waveguide laser are considered. Moreover, the effectiveness of the electric—field -assisted diffusion is demonstrated by experiments