近年來三族氮化物半導體材料吸引相當多的注意，因為這些材料有著寬頻、熱穩定性…等優點，除此之外這些半導體材料對於光學應用也有相當大潛力，本篇論文將探討在通訊波段為1552奈米下將模態轉換器與圓環共振器製作在氮化鎵(GaN)基板上所展現出的特性以及未來的發展性與潛力。實驗過後成功的運用連接複數個多模干涉(MMI)波導製作出上述提到的兩個元件，因為多模干涉波導有製成簡易、高容忍度、製作彈性高…等優點，利用這些MMI的特性成功將模態轉換器和圓環共振器製作出來。
模態轉換器方面透過串連1×2對稱型MMI、相位調變區以及4×4通常型MMI完成該元件，這個模態轉換器成功的將輸入基礎模態轉換為一階模態輸出，且輸出有著波長獨立性，能夠在輸入光波段內都有轉換效果，在未來將會以tapered MMI取代傳統MMI減少元件長度達到改善傳輸損耗的問題。
圓環共振器方面將3個1×2通常型MMI用圓環連接起來，透過MMI分光的效果將部分輸入光引導至圓環共振腔內，使得要求的共振波長1552奈米能夠在圓環共振腔內共振，令through端有帶拒濾波器的特性而drop端有帶通濾波器的特性，且through端以及drop端所量測到枝對比度分別為10dB以及5dB，未來我們將使用33:67分光比例的MMI取代原本50:50分光比例的MMI增加圓環共振器的對比度。

Mode converter and ring resonator are fabricated on the GaN wafer. Both of the devices are composed of several MMI waveguides and fabricated by ICP-RIE dry etching. We measure the characteristic of the device by CCD camera and the optical spectrum analyzer. First, mode converter output port shows exactly two light spot and frequency spectrum characteristic is similar with the input source. These result present that the mode converter can work properly under input source wavelength range. Second, the through port and drop port of the ring resonator has the contrast 10dB and 5dB, respectively. The through port spectrum is opposite to the drop port spectrum, same as the theory describing. Mode converter shows the function of converting fundamental mode into the first order mode but there is ripple on the spectrum. This is a problem that can be improved in the future. The ring resonator has the function of filtering wavelength but the contrast of the drop port is only 5dB which is smaller than the through port. The contrast can be improved by optimize the fabrication process or using the tapered MMI waveguide.

第一章
[1] D T Dul and P Korecki, “Wavelet analysis of white beam x-ray fluorescence holograms: determination of lattice sites and imaging of local atomic structure,” New J. Phys. , vol. 14, no. 11304, pp.6-8 , Nov. 2012.
[2] S. Nakamura, M. Senoh, S.-I. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, H. Kiyoku, and Y. Sugimoto, “InGaN-based multi-quantumwell-structure laser diodes,” Jpn. J. Appl. Phys., vol. 35, no. 1B, pp.L74–L76, Jan. 1996.
[3] Mei-Xin Feng, Jian-Ping Liu, Shu-Ming Zhang, De-Sheng Jiang, Zeng-Cheng Li, De-Yao Li, Li-Qun Zhang, Feng Wang, Hui Wang, and Hui Yang, “Design Considerations for GaN-Based Blue Laser Diodes With InGaN Upper Waveguide Layer,” IEEE J. Sel. Top. Quant., vol. 19, no. 4, pp. 1500705, Dec. 2012.
[4] Seong-Ran Jeon, Myong Soo Cho, Min-A Yu, and Gye Mo Yang, “GaN-Based Light-Emitting Diodes Using Tunnel Junctions,” IEEE J. Sel. Top. Quant., vol. 8, no. 4, pp. 739-743, Aug. 2002.
[5] Ching-Hsueh Chiu, Po-Min Tu, Chien-Chung Lin, Da-Wei Lin, Zhen-Yu Li, Kai-Lin Chuang, Jet-Rung Chang, Tien-Chang Lu, Hsiao-Wen Zan, Chiang-Yao Chen, and Hao-Chung Kuo, “Highly Efficient and Bright LEDs Overgrown on GaN Nanopillar Substrates,” IEEE J. Sel. Top. Quant., vol. 17, no. 4, pp.971-978, Aug. 2011.
[6] T. Someya, K. Tachibana, J. Lee, T. Kamiya, and Y. Arakaw, “Lasing emission from an In Ga N vertical cavity surface emitting laser,”
Jpn. J. Appl. Phys., vol. 37, no. 12A, pp. L1424–L1426, Dec. 1998.
[7] Hongjuan Huang, Dawei Yan, Guosheng Wang, Feng Xie, Guofeng Yang, Shaoqing Xiao, and Xiaofeng Gu, “GaN-based p–i–n ultraviolet photodetectors with a thin p-type GaN layer on patterned sapphire substrates,” Chinese Opt. Lett., vol. 12, no. 9, pp. 092301–092304, Sep. 2014.
[8] Xiucheng Huang,Zhengyang Liu,Qiang Li,and Fred C. Lee, “Evaluation and Application of 600 V GaN HEMT in Cascode Structure,” IEEE trans. power electron, vol. 29, no. 5, pp. 2453-2461, May 2014.
[9] Frank Schwierz, “A electron mobility model for wurtzite GaN,” Solid-State Electron., vol. 49, no. 6, pp. 889-895, June 2005.
[10] R. Hui, Y. Wan, J. Li, S. X. Jin, J. Y. Lin, and H. X. Jiang, “Birefringence of GaN/AlGaN optical waveguides,” Appl. Phys. Lett., vol. 83, no.9, pp. 1698-1700, Sep. 2003.
[11] R. Dylewicz, S. Patela, A. Hogg, P. W. Fry, P. J. Parbrook, R. Airey, and A. Tahraoui, “In-Plane Optical Anisotropy of GaN Refractive Index in Visible Light Region,” IEEE Photon. Technol. Lett., vol. 21, no. 14, pp. 966-968, Jul. 2009
[12] Umit Ozgur, Grady Webb-Wood, Henry O. Everitt, Feng Yun, and Hadis Morkoc, “Systematic measurement of AlxGa1ÀxN refractive indices,” Appl. Phys. Lett., vol. 79, no.25, pp. 4103-4105, Dec. 2001.
[13] Ching-Hsueh Chiu, Po-Min Tu, Chien-Chung Lin, Da-Wei Lin, Zhen-Yu Li, Kai-Lin Chuang, Jet-Rung Chang, Tien-Chang Lu, Hsiao-Wen Zan, Chiang-Yao Chen, Hao-Chung Kuo, Shing-Chung Wang, and Chun-Yen Chang, “Highly Efficient and Bright LEDs Overgrown on GaN Nanopillar Substrates,” IEEE J. Quantum Electron., vol. 17, no.4, pp. 971-978, Jul. 2011.
[14] Cheng-Liang Wang, Jyh-Rong Gong, Ming-Fa Yeh, Bor-Jen Wu, Wei-Tsai Liao, Tai-Yuan Lin, and Chung-Kwei Lin, “Improvement in the Characteristics of GaN-Based Light-Emitting Diodes by Inserting AlGaN–GaN Short-Period Superlattices in GaN Underlayers,” IEEE Photon. Technol. Lett., vol. 18, no.14, pp. 1497-1499, July 2006.
[15] Seong-Ran Jeon, Myong Soo Cho, Min-A Yu, and Gye Mo Yang, “GaN-Based Light-Emitting Diodes Using Tunnel Junctions,” IEEE J. Quantum Electron., vol. 8, no.4, pp. 739-743, July 2002
[16] S. Nakamura, “InGaN-based violet laser diodes,” Semicond. Sci. Technol., vol. 14, no. 6, pp. R27-40, June 1999.
[17] Takao Miyajima, Tsuyoshi Tojyo, Takeharu Asano,Katsunori Yanashima, Satoru Kijima, Tomonori Hino,Motonobu Takeya, Shiro Uchida, Shigetaka Tomiya,Kenji Funato, Tsunenori Asatsuma, Toshimasa Kobayashi and Masao Ikeda, “GaN-based blue laser diodes,” J. Phys.: Condens. Matter, vol. 13, no.32, pp. 7099-7114, July 2001.
[18] Guan-Lin Su, Thomas Frost, Pallab Bhattacharya, and John M. Dallesasse, “Physical model for high indium content InGaN/GaN self-assembled quantum dot ridge-waveguide lasers emitting at red wavelengths (λ∼630 nm),” Opt. Express, vol. 23, no.10, pp. 12850-12865, May 2015.
[19] Jing Zhang, Tsung-Yang Liow, Mingbin Yu, Guo-Qiang Lo, and Dim-Lee Kwong, “Silicon waveguide based TE mode converter,” Opt. Express, vol. 18, no.24, pp. 25264-25270, Nov. 2010.
[20] Lianxi Jia, Junfeng Song, Tsung-Yang Liow, Xianshu Luo, Xiaoguang Tu, Qing Fang, Sing-Chee Koh, Mingbin Yu, and Guoqiang Lo, “ Mode size converter between high-indexcontrast waveguide and cleaved single mode fiber using SiON as intermediate material,” Opt. Express, vol. 22, no.19, pp. 23652-23660, Sep. 2014.
[21]Qing Fang, Junfeng Song, Xianshu Luo, Mingbin Yu, Guoqiang Lo, and Yuliang Liu, “Mode-size converter with high coupling efficiency and broad bandwidth,” Opt. Express, vol. 19, no.22, pp. 21588-21594, Oct. 2011.
[22] Joonsoo Kim, Seung-Yeol Lee, Hyeonsoo Park, Kyookeun Lee, and Byoungho Lee, “Reflectionless compact plasmonic waveguide mode converter by using a mode-selective cavity,” Opt. Express, vol. 23, no.7, pp. 9004-9013, Apr. 2015.
[23] Yutaka Chaen, Ryota Tanaka, and Kiichi Hamamoto, “Optical Mode Converter Using Multi-Mode Interference Structure,”18th Microoptics Conference (MOC’13), Tokyo, Japan, pp. 1-2, Oct. 2013.
[24] B. E. Little, J. S. Foresi, G. Steinmeyer, E. R. Thoen, S. T. Chu, H. A. Haus, E. P. Ippen, L. C. Kimerling, and W. Greene, “Ultra-Compact Si–SiO2 Microring Resonator Optical Channel Dropping Filters,” IEEE Photon. Technol. Lett., vol. 10, no.4, pp. 549-551, Apr. 1998.
[25] Dominik G. Rabus and Michael Hamacher, “MMI-Coupled Ring Resonators in GaInAsP–InP,” IEEE Photon. Technol. Lett., vol. 13, no.8, pp. 812-814, Aug. 2001.

第二章
[1] Lucas B. Soldano and Erik C. M. Pennings, “Optical Multi-Mode Interference Devices Based on Self-Imaging : Principles and Applications,” J. Lightwave Technol., vol. 13, no. 4, pp. 615-627, Apr. 1995.
[2] Teppei Fukuda, Kazunori Okamoto, Yasuhiro Hinokuma, and Kiichi Hamamoto, “Phase-Locked Array Laser Diodes (LDs) by Using 1×N Active Multimode-Interferometer (MMI),” IEEE Photon. Technol. Lett., vol. 21, no. 3, pp. 176-178, Feb. 2009.
[3] R.W. Purnamaningsih, N.R. Poespawati, I. Saraswati, E. Dogheche, “Design of GaN based optical modulator with Mach-Zehnder interferometer structure,” WSEAS Trans. Commun., vol. 13, no. 25, pp. 229-233, Jan. 2014.
[4] Shu-Hao Fan, Daniel Guidotti, Hung-Chang Chien, and Gee-Kung Chang, “Compact polymeric four-wavelength multiplexers based on cascaded step-size MMI for 1G/10G hybrid TDM-PON applications,” Opt. Express, vol. 16, no. 17, pp. 12664-12669, Aug. 2014.
[5] Juerg Leuthold, Juerg Eckner, Emil Gamper, Pierre A. Besse, and Hans Melchior, “Multimode Interference Couplers for the Conversion and Combining of Zero- and First-Order Modes,” J. Lightwave Technol., vol. 16, no. 7, pp. 1228-1239, July 1998.
[6] Yingyan Huang, Guoyang Xu, and Seng-Tiong Ho, “An Ultracompact Optical Mode Order Converter,” IEEE Photon. Technol. Lett., vol. 18, no. 21, pp. 2281-2283, Nov. 2006.
[7] Kirankumar Rajshekhar Hiremath, Coupled Mode Theory Based Modeling and Analysis of Circular Optical Microresonators, Kirankumar R. Hiremath, pp. 8-17, 2005
[8] Yariv A., “Coupled-Mode Theory for Guided-Wave Optics,” IEEE J. Quantum Electron. , vol. QE-9, no. 9, pp. 919-933, Sep.1973.
[9] Trung-Thanh Le, “Design of A Polarization-Independent MMI SOI Coupler Based Microresonator Using Sandwich Structures,” J. Eng. Sci. Technol., vol. 8, no. 2, pp. 120-130, Apr. 2013.
[10] Dominik G. Rabus and Michael Hamacher, “MMI-Coupled Ring Resonators in GaInAsP–InP,” IEEE Photon. Technol. Lett., vol. 13, no. 8, pp.812-814, Aug. 2001.

第三章
[1] Xiaobo Xing; Xiaoqing Deng; Baojun Li; Bharat S. Chaudhari, “Analysis of GaN-based single-mode rib waveguide with large cross section,” J. Micro/Nanolith, vol. 5, no. 3, p.033009, July 2006.
[2] Chih-Chiang Kao, H. C. Kuo, K. F. Yeh, J. T. Chu, W. L. Peng, H. W. Huang, T. C. Lu, and S. C. Wang, “ Light–Output Enhancement of Nano-Roughened GaN Laser Lift-Off Light-Emitting Diodes Formed by ICP Dry Etching,” IEEE Photon. Technol. Lett., vol. 19, no. 11, pp. 849-851, June 2007.
[3] Jewon Lee, Hyun Cho, David C. Hays, Cammy R. Abernathy, Stephen J. Pearton, Randy J. Shul, G. Allen Vawter and J. Han, “Dry Etching of GaN and Related Materials: Comparison of Techniques,” IEEE J. Quantum Electron., vol. 4, no. 3, pp. 557-563, May 1998.

第四章
[1] H. P. Weber, F. A. Dunn, and W. N. Leibolt, “Loss Measurements in Thin-Film Optical Waveguides,” Appl. Opt., vol.12, no.4, pp.755-757, Apr. 1973.
[2] Graham T. Reed, Andrew P. Knights, Silicon Photonics An Introduction, John Wiley & Sons, Ltd, pp.91-97, 2004.
[3] Sareh Taebi, Mohammadreza Khorasaninejad, and Simarjeet Singh Saini, “Modified Fabry–Perot interferometric method for waveguide loss measurement,” Appl. Opt., vol.47, no.35, pp.6625-6630, Dec. 2008.

第五章
[1] Yutaka Chaen, Ryota Tanaka, and Kiichi Hamamoto, “Optical Mode Converter Using Multi-Mode Interference Structure,” Microoptics Conference (MOC),2013 18th, pp.1-2, Oct. 2013.
[2] Dominik G. Rabus and Michael Hamacher, “MMI-Coupled Ring Resonators in GaInAsP–InP,” IEEE Photon. Technol. Lett., vol.13, no.8, pp.812-814, Aug. 2001.
[3] Dan-Xia Xu, Adam Densmore, Philip Waldron, Jean Lapointe, Edith Post, André Delâge, Siegfried Janz, Pavel Cheben, Jens H. Schmid and Boris Lamontagne, “High bandwidth SOI photonic wire ring resonators using MMI couplers,” Opt. Express, vol.15, no.6, pp.3149-3155, Mar. 2007.
[4] B. E. Little, S. T. Chu, H. A. Haus, J. Foresi, and J.-P. Laine, “Microring Resonator Channel Dropping Filters,” J. Lightwave Technol., vol.15, no.6, pp.998-1005, June 1997.
[5] Jan Niehusmann, Andreas Vörckel, and Peter Haring Bolivar, “Ultrahigh-quality-factor silicon-on-insulator microring resonator,” Opt. Lett., vol.29, no.24, pp.2861-2863, Dec. 2004.
[6] Kehinde A. Latunde-Dada and Frank P. Payne, “Theory and Design of Adiabatically Tapered Multimode Interference Couplers,” J. Lightwave Technol., vol.25, no.3, pp.834-839, Mar. 2007.
[7] P. P. Sahu, “A Tapered Structure for Compact Multimode Interference Coupler,” IEEE Photon. Technol. Lett., vol.20, no.8, pp.638-640, Apr. 2008.
[8] Hongzhen Wei, Jinzhong Yu, Zhongli Liu, Xiaofeng Zhang, Wei Shi, and Changshui Fang, “Fabrication of 4×4 Tapered MMI Coupler with Large Cross Section,” IEEE Photon. Technol. Lett., vol.13, no.5, pp.466-468, May 2001.
[9] Juerg Leuthold, Juerg Eckner, Emil Gamper, Pierre A. Besse, and Hans Melchior, “Multimode Interference Couplers for the Conversion and Combining of Zero- and First-Order Modes,” J. Lightwave Technol., vol. 16, no. 7, pp. 1228-1239, July 1998.