以飛秒雷射雙光子聚合光波導及反射面

The Fabrication of Optical Waveguide and Micro-Reflectors based on Femtosecond Two Photon Polymerization Technique

鄭勢嚴(Shih-yen Cheng)

指導教授 ： 戴朝義

國立中央大學/理學院/光電科學研究所/碩士(2012年)

摘要

本研究以Light tools光學模擬軟體對於不同角度反射面的光連結架構進行模擬，發現當斜面角度為43度到46.5度時，由面射型雷射光源至光偵測器的能量傳輸效率高於80%。其次針對不同半徑的圓弧反射面進行模擬，由結果可知圓弧面的最大反射效率相較於平面反射面可提升10%。在實驗方面，使用鎖模鈦藍寶石飛秒雷射在高分子材料中引發雙光子吸收效應聚合製作斜面微結構。藉由物鏡離焦平面的距離改變照射至光阻的光點強度分佈，成功製作出43度的反射斜面。使用近場掃描光學顯微鏡對於製作出的斜面結構進行表面粗糙度量測，確認其表面平滑度可達35nm(≦λ/10)足夠做為光學等級反射面。最後對於結構進行光場量測，藉反射光場的強度分佈變化來判定所製作的斜面具有匯聚光束的效果。

關鍵字

飛秒雷射 ； 雙光子聚合 ； 反射面 ； 光連結

並列摘要

In this study, optical interconnects with various reflection angles are simulated by ray-tracing based software- Light toolsTM. It is found that the transmission efficiency from the vertical cavity surface emitting laser (VCSEL) to the photodiode (PD) can be higher than 80% as the angle of the reflector is within 43 degree to 46.5 degree. Next, the simulation was carried out for curved reflectors with various radii. Compared to flat reflector, the maximum reflection efficiency can be improved by 10%. Experimentally, mode-locked Titanium-Sapphire laser was used for the fabrication of the slanted structures basing on two-photon absorption polymerization technique. By varying the defocusing length so as to change the intensity distribution on photo-resist, a reflecting surface of 43 degree is successfully fabricated. Scanning near-field optical microscope (SNOM) measurement shows that the surface roughness is less than 35nm (≦λ/10), demonstrating the capability of optical-grade reflecting surface. The intensity distribution of the reflected light confirms the focusing effect of the fabricated surface.

並列關鍵字

reflector ； optical interconnect ； two photon polymerization ； femtosecond laser

參考文獻

[1] T.H Maiman, “Stimulated Optical Radiation in Ruby,” Nature 187, pp. 493-494(4736)

[2] M. Schneider, T. Kuhner, J. Mohr, and D. Maas,“Fibers in Printed Circuit Boards With Passively Aligned Coupling,” IEEE, Vol. 28, No. 15, pp.2121-2128(2010)

[3] H.-L. Hsiao, H.-C. Lan, C.-C. Chang, C.-Y. Lee, S.-P. Chen, “Compact and passive-alignment 4-channel × 2.5Gbps optical interconnect modules based on silicon optical benches with 45° micro-reflectors,” Optics Express, Vol. 17, No. 26, pp.24250-24260(2009)

[6] Y. Takagi, A. Suzuki, T. Horio, T. Ohno, T. Kojima,“ Low-Loss Chip-to-Chip Optical Interconnection Using Multichip Optoelectronic Package With 40-Gb/s Optical I/O for Computer Applications,” IEEE, Vol.28, No. 20, pp.2956-2963(2010)

[7] T. Ishigure and Y. Nitta, “Polymer optical waveguide with multiple graded index cores for on-board interconnects fabricated using soft-lithography,” Optics Xepress, Vol.18, No.13, pp.14191-14201(2010)