高分子簡式同調耦合大角度光功率分離器之研製

Fabrication of Wide-Angle Optical Power Splitter Using Benzocyclebutene Waveguide with Simplified Coherently-Coupled Segments

倪其利(Chi-Li Ni)

指導教授 ： 王維新

國立臺灣大學/電機資訊學院/光電工程學研究所/碩士(2007年)

https://doi.org/10.6342/NTU.2007.00665

摘要

本研究以波長248 nm的KrF準分子雷射，透過石英光罩直接將紫外光雷射照射在高分子材料benzocyclobutene上改變折射率製作光波導元件，製作出1.55 μm光源之下的簡式同調耦合的彎曲結構、一分二光功率分離器(Y形分岔)、以及一分四光功率分離器，使用的彎曲角度依序為0.5°、1.5°、2.5°、3°、2.5°、1.5°、1°。模擬結果顯示，與傳統彎曲方式比較，簡式同調耦合彎曲除了可以縮短元件的長度外，也有較高的傳輸效率。實作時採固定雷射強度及重複率，並選用不同的紫外光雷射發數。首先利用S形結構量測光功率值以求不同雷射發數下的同調耦合長度，再用一分二光功率分離器求其分岔長度，最後再將製程條件應用在一分四光功率分離器的設計上。實驗所得到的總傳輸率可達81.86%，輸出不均勻率為0.81 dB。而模擬的總傳輸率為85.6%，輸出不均勻率為0.57dB，此與實驗所得到的數據相當的吻合。

關鍵字

光波導 ； 準分子雷射 ； 高分子 ； 光功率分離器 ； 簡式同調耦合

並列摘要

Benzocyclobutene (BCB) optical waveguide devices fabricated by 248 nm krypton fluorine excimer laser illumination are demonstrated. The optical devices of interest are S-bend, 1×2 optical power splitter (Y-branch), and 1×4 optical power splitter with simplified coherently-coupled (SCC) segments. The bend angles of these segments are designed as 0.5°, 1.5°, 2.5°, 3°, 2.5°, 1.5°, and 0.5° for the 1.55 μm wavelength. Simulated results show that with use of SCC structure, the device length is shortened and the transmission efficiency is enhanced as compared with those of the traditional bending structures. Using various numbers of laser shots, the coherent length is determined by the S-bend structure, and the split length is determined by the 1×2 optical power splitter. Based on the coherent length and the split length, a 1×4 optical power splitter is fabricated. The measured transmission efficiency is 81.86%, and the maximum imbalance is 0.81 dB, which agree quite well with the simulation results 85.6%, and 0.57 dB respectively.

並列關鍵字

Benzocyclobutene ； BCB ； Optical Waveguide ； Optical Power Splitter Excimer Laser ； KrF ； Simplified Coherently-Coupled Segments ； SCC

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