鋅鎳共同擴散式鈮酸鋰光波導折射率分布之研究

The Study of Refractive Index Profiles of Zn:Ni:LiNbO3 Optical Waveguides

蔣宗禹(Tsung-Yu Chiang)

指導教授 ： 蔡宛卲

國立暨南國際大學/科技學院/應用材料及光電工程學系/碩士(2013年)

摘要

論文名稱: 鋅鎳共同擴散式鈮酸鋰光波導折射率分布之研究
院校系:暨南國際大學科技學院應用材料及光電工程學系 頁數:55
畢業時間:102年7月 學位別:碩士
研究生:蔣宗禹 指導教授:蔡宛卲
摘要
本論文探討在Z切鈮酸鋰基板上以鋅鎳共同擴散製作光波導，並且針對其製程特性、擴散行為、折射率模型做研究以及分析。
在製程方面，使用鎳金屬做為附著層，以解決鋅金屬對於鈮酸鋰基板附著力不佳的問題。擴散過程中，溫度不超過850℃，故鈮酸鋰基板沒有鋰離子外擴散的問題。為了分析擴散行為，使用二次離子質譜儀做縱深分析，針對不同的溫度以及擴散時間，對鋅鎳共同擴散鈮酸鋰光波導建立出擴散模型。
量測方面，使用改善式直接激發耦合法，直接將波長為1550nm的光源打入端面拋光的光波導。由於以往逆推折射率需要將實際量測到的光場做一次微分以及二次微分，使雜訊放大，故重建出來的折射率會失真。本研究在量測系統架設中，在光波導輸出端的物鏡加上微位移平台，同時以鎖向放大器給予一弦波電壓，使光場做週期性的震動，在使用傅利葉轉換在頻譜上選擇適當的一倍頻以及二倍頻訊號，最後在以反傅立葉轉換得到光場的一階微分場以及二階微分場，藉以取代直接微分，避免雜訊放大。
最後為了找出擴散模型以及折射率模型的關係，以近似方法分別得到擴散深度以及折射率深度，得到他們之間的關係。

關鍵字: 鋅鎳共同擴散式鈮酸鋰光波導;二次離子質譜;折射率分布

關鍵字

鋅鎳共同擴散式鈮酸鋰光波導 ； 二次離子質譜 ； 折射率分布

並列摘要

Title of Thesis：The Study of Refractive Index Profiles of Zn:Ni:LiNbO3 Optical Waveguides
Name of Institute：Department of Applied Materials and Optoelectronics Engineering, College of Science and Technology, National Chi-Nan University
Pages：55
Graduation Time：7/102 Degree Conferred：Master
Student Name：Tsung-Yu Chiang Advisor Name：Wan-Shao Tsai
Abstract
In this dissertation, optical waveguides were made by zinc (Zn) and nickel (Ni) co-diffusion on Z-cut lithium niobate substrate (ZNI: LiNbO3). The characteristics of fabrication process, diffusion behaviors and refractive index models were studied and analyzed.
In the waveguide fabrication process, Ni was used as an adhesion layer to solve the poor adhesiveness of Zn layer deposited on the substrate. In the diffusion process, the diffusion temperature was less than 850℃, so that the out-diffusion of lithium ion can be avoided. To study the diffusion characteristics, secondary ion mass spectrometry (SIMS) was measured for depth analysis at different diffusion temperature and time. Then the diffusion models of Zn and Ni co-diffusion were established.
For measurement, a modified end-fire coupling method was used for coupling the light at wavelength 1550 nm directly into the waveguides with end-facet polished. To avoid optical signal distortion during numerical differentiation when reconstructing index profile, a piezoelectric stage was used at output objective lens, and a lock-in amplifier was used for giving a sinusoidal voltage. The optical fields can then be vibrated periodically. Fourier transform was performed to retrieve the first and second-order derivatives of the optical fields for reconstruction of the refractive index profiles.
Finally, in order to find the relationship between the refractive index and diffusion model, the diffusion depth and depth of refractive index profile were both fitted. The correlation between these two depths can then be found.

Key words: Zn:Ni:LiNbO3 Optical Waveguides; Secondary-Ion-Mass Spectrometry; Refractive Index Profile

並列關鍵字

Zn:Ni:LiNbO3 Optical Waveguides ； Secondary-Ion-Mass Spectrometry ； Refractive Index Profile

參考文獻

[1] R. G. Hunsperger, Integrated Optics: Theory and Technology 5th ed., Springer, 2002.

[2] R. V. Schmidt and I. P. Kaminow, “Metal-diffused optical waveguides in LiNbO3,” Appl. Phys. Lett., vol. 25, no. 8, pp. 458-460, Oct. 1974.

[3] Y. P. Liao, D. J. Chen, R. C. Lu, and W. S. Wang, “Nickel-diffused lithium niobate optical waveguide with process-dependent polarization,” IEEE Photon. Technol. Lett., vol. 8, no. 4, pp. 548-550, Apr. 1996.

[4] W. M. Young, R. S. Feigelson, M. M. Fejer, M. J. F. Digonnet, and H. J. Shaw,“Photorefractive damage resistant Zn-diffused waveguides in MgO:LiNbO3,” Opt.Lett., vol. 16, pp. 995-997, 1991

[5] 徐文浩，“鋅鎳共同擴散式鈮酸鋰光波導元件之特性與應用”，國立台灣大學電機工程學研究所博士論文，2000.