| 摘要(英) |
In this study, we have used simulated annealing method to calculate the aperiodic domain inversion structure in LiNbO3 crystal. Moreover, we have applied this kind of structure on the electro-optically directional coupler. With the aperiodically poled LiNbO3 directional coupler (APPLNDC), it made the difference coupling result with periodically poled LiNbO3 directional coupler (PPLNDC). According to the difference arrangement of the poling structure, the directional coupler can get the difference coupling result, and thus APPLNDC can be more adjustable. In this study, our aperiodical design can make the APPLNDC get the higher fabrication tolerance, higher switched bandwidth and higher voltage tolerance. Furthermore, we fabricate the APPLNDC chip to verify our simulation result.
We used our standard lithography process and Titanium diffusion process to fabricate directional coupler and the aperiodically poled LiNbO3 was made by our standard CLN(congruent LiNbO3) poling process. After the poling process, we used the E-gun and Thermal machine to fabricate the electrode. Finally, we did the cutting and the end-face polishing process, then the APPLNDC chip was ready to be measured.
On the APPLNDC chip, there are different coupling length of the directional couplers. With the aperiodically poled LiNbO3, different coupling length of the directional couplers can have the same working voltage to reach crossover state at approximately 30V, and reach the straight-through state at approximately 50V. The average switched voltage is roughly 17.85V.
The aperiodically LiNbO3 also can enhance the working bandwidth of the directional couplers. By our measurement, the APPLNDC can work from 1493.88nm to 1643.05nm, so the bandwidth is approximately 149.17nm. Compare to PPLNDC’s bandwidth 61.53nm, APPLNDC is 2.42 times boarder than PPLNDC. Directional coupler as an optical communication component, the bandwidth increases, the transmission capacity can also be increased, the characteristics of broadband has become a major advantage of this study.
In the future, the APPLNDC can also be used to apply a coplanar waveguide electrode to modulate the light in a traveling wave, to make it a high-speed modulated optical switcher, or to further develop an integrated optical logic gate. By using the aperiodically poled LiNbO3 and then applying the high-speed modulated electrode, the electro-optically switched directional coupler will obtain more application and increase the competitiveness in the optical communication.
This study have got the Best Students Poster Award in CUDOS:2017workshop. I was the second author：
Hung-Pin Chung, Shih-Yuan Yang, Sung-Lin Yang, Tsai-Yi Chien, Kuang-Hsu Huang, Yen-Yu Chou, Kai Wang, Dragomir N. Neshev, and Yen-Hung Chen. “Electro-optic aperiodically poled Lithium Niobate directional couplers” CUDOS 2017 Annual workshop, Australia, Best Poster award of nonlinear quantum photonics, (2017). |
| 參考文獻 |
[1] S. E. miller, “Integrated Optics : an introduction ,” Bell. Syst. Tech. J., 48, p.2059-2069, 1969.
[2] E. A. J. Marcatili, “Dielectric rectangular waveguide and directional coupler for integrated optics” Bell. Syst. Tech. J., 48, p.2071-2102, 1969.
[3] M.Papuchon, “Electrically switched optical directional coupler: Cobra” Appl. Phys. Lett. 27, 289, 1975.
[4] R. V. Schmidt, “Efficient optical waveguide switch/amplitude modulator” Opt. Lett., vol.2, No.2, 1978.
[5] Scott A. Samson,”Two-Section Reversed ∆β Switch with Uniform Electrodes and Domain Reversal” IEEE PTL, vol.9, No.2,p197-199, 1997.
[6]楊松霖，「以週期性晶疇極化反轉鈦擴散鈮酸鋰波導晶片作為偏振可調定向耦合器之研究」，國立中央大學光電所碩士論文，2012。
[7]簡采毅，「電光非週期性晶疇極化反轉鈮酸鋰波導定向耦合元件之研究」，國立中央大學光電所碩士論文，2013。
[8] Yariv & Yeh “Optical waves in crystals” chap.11, p463, 2003.
[9] Dieter H. Jundt, “Temperature-dependent Sellmeier equation for the index of refraction ne, in congruent lithium niobate” Opt. Lett., vol.22, No.20, 1997.
[10] GJ Edwards, and M Lawrence “A temperature-dependent dispersion equation for congruently grown lithium niobate”, Optical and quantum electronics, vol.16, p373, 1984.
[11] Yariv & Yeh “Optical waves in crystals” chap.7, p232, 2003.
[12] H. Kogelnik, ”Switched directional couplers with alternating ∆β ” IEEE JQE, vol. QE-12 ,No.7, p.396-401, 1976.
[13]呂學璁，「以非週期性晶疇極化反轉鈮酸鋰晶體作為電光波長調變光參量產生器」，國立中央大學光電所碩士論文，2010。
[14] Shintaro Miyazawa, “Ferroelectric Domain Inversion in Ti-diffused LiNbO3 Optical Waveguide.”, Journal of Applied Physics, 50, 1979
[15] J. Webjorn, F. Laurell, G. Arvidsson, “Blue Light Generated by Frequency Doubling of Laser Diode Light in a Lithium Niobate Channel Waveguide.”, IEEE Photonics Technology Letters, 1, 1989.
[16] Alan C. G. Nutt, Venkatraman Gopalan, and Mool C.Gupta, “Domain Inversion in Linbo3 Using Direct Electron-beamwriting.”, Applied Physics Letters, 60, 1992.
[17] A. Agronin, Y. Rosenwaks, and G. Rosenman, “Ferroelectric Domain Reversal in LiNbO3 Crystals Using High-voltage Atomic Force Microscopy”, Applied Physics Letters, 85, 2004.
[18] Duan Feng, Nai-Ben Ming, Jing-Fen Hong, Yong-Shun Yang, Jin-Song Zhu, Zhen Yang, and Ye-Ning Wang, “Enhancement of Second-Harmonic Generation in Linbo3 Crystals with Periodic Laminar Ferroelectric Domains.”, Applied Physics Letters, 37, 607, 1980.
[19] L. E. Myers, G. D. Miller, R. C. Eckardt, M. M. Fejer, R. L. Byer, W. R. Bosenberg,“Quasi-phase-matched 1.064-mm-pumped Optical Parametric Oscillator in Bulk Periodically Poled LiNbO3.”, Optics Letters, Vol. 20, No.1, 1995.
[20]N. Metropolis, A. W. Rosenbluth, M. N. Rosenbluth, A. H. Teller, and E. Teller, “Equation of State Calculationsby Fast Computing Machines.”, Journal of Chemical Physics, 1953.
[21]S. P. Brooks, B. J. T. Morgan -The Statistician, p.241-257,1995.
[22] Bor-Uei Chen, Antonio C. Pastor, and Hiroshi Shimizu , “Elimination of Li20 out-diffusion waveguide in LiNbO3 and LiTaO3” Appl. Phys. Lett., 30, 11, 1977.
[23] Klyoshi Nakamura, and Haruyasu Ando, and Hiroshi Shimizu , “Ferroelectric domain inversion caused in LiNbO3 plates by heat treatment.” Appl. Phys. Lett., 50, 18, 1987.
[24] L. L. BUHL ,“Optical losses in metal/SiO2-clad Ti:LiNbO3 waveguide.” Electronics Lett., Vol.19 ,No.17, p.659-660, 1983.
[25] Syoji Yamada and Makoto Minakata, “DC Drift Phenomena in LiNbO3 Optical Waveguide Devices”, Japanese Journal of Applied Physics, Vol.20, No.4, p.733-737, April, 1981.
[26] R. C. Alferness, C. H. Joyner, L. L. Buhl, S. K. Korotky, “High-speed Traveling-Wave Directional Coupler Switch/Modulator for λ = 1.32μm”, IEEE Journal of Quantum Electronics, Vol.QE-19, No.9, September, 1983. |
[Endnote RIS 格式]
[相關文章]
[文章引用]
[完整記錄]
[館藏目錄]
[檢視]
plurk
funp
live
udn
HD
myshare
netvibes
friend
youpush
delicious
baidu
Google bookmarks
del.icio.us
hemidemi
facebook
twitter
google
reddit