The Study on The Novel Power Splitter Using Coherently Coupled Effect With Y-Type Asymmetric Split Ratio

• Main Authors: Kuan-Yu Chen, 陳冠宇
• Other Authors: Wei-Yu Lee
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/53589102468477017958

碩士 === 中華技術學院 === 機電光工程研究所碩士班 === 97 === Based on the coherent-coupling effect, a novel wide angle variable-ratio Y-branch power splitter with Ti-diffused LiNbO3 waveguide is proposed. The Y-branch power splitter consists of a coherent-coupling bending waveguide and a straight waveguide. The simulation results show that the output power of our proposed power splitter is wide angle and variable-ratio by shifting the position where the straight waveguide separated from the coherent-coupling waveguide. Y-Branch waveguides are fundamental element for optical waveguide devices. Recently, high-density optical integrated circuits have become of interest. In order to increase the density of optical components on the same chip, developing a low-loss Y-branch waveguide with a large branching angle is of great significance. However, the conventional Y-branch waveguide suffers severe radiation loss when the branching angle is larger than 2°. To reduce the radiation loss, the branching angle must be small and the device length is therefore increased. Several efforts have been made to overcome the loss problem, especially when the branching angle is large. Low loss bending has been easily achieved by utilizing coherently coupled bends. In this paper, based on the coherent-coupling effect, we proposed a novel wide angle variable-ratio Y-branch power splitter with Ti-diffused LiNbO3 waveguide. The Y-branch power splitter consists of a coherent-coupling bending waveguide and a straight waveguide. The simulation results show that the output power of our proposed power splitter is wide angle (up to 4°) and variable-ratio by shifting the position where the straight waveguide separated from the coherent-coupling waveguide. In addition, only one photolithographic steps is required to fabricate our proposed device, which greatly simplifies the fabrication process.