- 學位論文
紫外光雷射照射高分子多模干涉元件之研製
Fabrication of Benzocyclobutene Multimode Interference Devices by Ultraviolet Laser Illumination
摘要
本研究成功地在通訊波長1550nm下，以紫外光雷射照射法製作出1 4、2 2、4 4三種結構的多模干涉光功率分離器。實驗上以波長248nm之KrF準分子脈衝雷射，透過石英光罩照射苯並環丁烯高分子材料，製作通道式單模波導。波導寬度設定為7μm，折射率差可在0.0027至0.003範圍內調整雷射發數。1 4多模干涉光功率分離器於干涉長度1520 μm時，具有95.52%傳輸率與0.41dB不等分率；2 2多模干涉耦合器於干涉長度1900μm具有92.96%傳輸率與0.08dB不等分率；4 4多模干涉耦合器於干涉長度8400μm，由外側輸入具有86.87%傳輸率與0.84dB不等分率，由內側輸入具有82.34%傳輸率與0.4dB不等分率，三種元件與模擬值的傳輸率誤差均小於3.22%。紫外光雷射照射法之BCB光波導元件因無側壁粗糙度問題，與其他製程或材料相較比有較小的傳播損耗，製程上的優點有以下三點，簡單省時、可控制折射率差、製程條件準確，故元件表現與模擬結果相當接近。
並列摘要
Buried-type benzocyclobutene (BCB) multimode interference (MMI) optical power splitters fabricated by the ultraviolet laser illumination are presented. The devices of interest are 1 4, 2 2, and 4 4 MMI devices. The BCB polymer is illuminated by 248nm krypton fluorine excimer pulse laser through a quartz mask. The single mode waveguide has width of 7μm and refractive index of 0.0027 to 0.003. The best 1 4 MMI device exhibits a transmission of 95.52% and an imbalance of 0.41dB with interaction length of 1520μm. The best 2 2 MMI device exhibits a transmission of 92.96% and an imbalance of 0.08dB with interaction length of 1900μm. The best 4 4 MMI device has an interaction length of 8400μm, which exhibits a transmission of 86.87% and an imbalance of 0.84dB when light is input from the outer access waveguides, and a transmission of 82.34% and an imbalance of 0.4dB when light is input from the inner access waveguides. Without the problem of side-wall roughness, BCB MMI devices fabricated by ultraviolet laser illumination exhibit smaller insertion loss as compared with those by other polymer and process. Experimental results, which agree quite well with the simulated results, show the BCB MMI power splitters can be fabricated with good controllability, high accuracy, and short time.