光纤端面耦合周期极化铌酸锂(PPLN)薄膜波导器件的研究

人工晶体学报 ›› 2024, Vol. 53 ›› Issue (8): 1319-1325.

光纤端面耦合周期极化铌酸锂(PPLN)薄膜波导器件的研究

马翠坪^1,2,3, 陈家颖^2,3,4, 陈怀熹^3,5, 梁万国^2,3, 伍秋林^2,3,4, 冯新凯⁶

1.福建师范大学物理与能源学院,福州 350117;
2.中国科学院福建物质结构研究所,福州 350002;
3.中国福建光电信息科学与技术创新实验室,福州 350108;
4.中国科学院大学,北京 100049;
5.福建师范大学光电与信息工程学院,福州 350117;
6.福建农林大学安溪茶学院,泉州 362406

收稿日期:2024-03-11 出版日期:2024-08-15 发布日期:2024-08-14
通信作者: 冯新凯,博士,讲师。E-mail:fdfxk@foxmail.com
作者简介:马翠坪(1997—),女,四川省人,硕士研究生。E-mail:1067941466@qq.com
基金资助:
福建省STS计划配套项目(2022T3012);福建农林大学安溪茶学院青年骨干培养基金(ACKY2023021);福建省光电子信息科技创新实验室自主部署项目(2021ZZ104);福建省光电子信息科技创新实验室福州市2023年揭榜挂帅项目(2023ZD012);合肥国家实验室量子科技仪器专项(2023YQ02002)

Study on Fiber End-Face Coupled Periodically Poled Lithium Niobate (PPLN) Thin Film Waveguide Device

MA Cuiping^1,2,3, CHEN Jiaying^2,3,4, CHEN Huaixi^3,5, LIANG Wanguo^2,3, WU Qiulin^2,3,4, FENG Xinkai⁶

1. College of Physics and Energy, Fujian Normal University, Fuzhou 350117, China;
2. Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China;
3. Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350108, China;
4. University of Chinese Academy of Sciences, Beijing 100049, China;
5. College of Photonic and Electronic Engineering, Fujian Normal University, Fuzhou 350117, China;
6. Anxi College of Tea Science, Fujian Agriculture and Forestry University, Quanzhou 362406, China

Received:2024-03-11 Online:2024-08-15 Published:2024-08-14

摘要/Abstract

摘要： 通过有限元模拟器从理论上分析了在理想光学系统中实现光纤与周期性极化铌酸锂(PPLN)波导之间高效耦合的可行性。仿真模拟了单模保偏光纤和透镜光纤在空间中的发散情况。针对截面尺寸为10 μm×10 μm、长度为20 mm的PPLN脊形波导,进行了与两种不同光纤的直接端面耦合模拟分析。分析发现,尽管透镜光纤的耦合效率高达95%,但其基模占比却不足5%。鉴于PPLN倍频器件主要依赖于激光的基模进行工作,这使透镜光纤的耦合效率在实际应用中显得相对较低。相比之下,单模保偏光纤的基模占比高达93.8%,显示出更为优越的性能。因此,本文选择了单模保偏光纤与PPLN脊形波导进行封装测试。实验结果表明:当温度为24.8 ℃,从光纤放大器输出的泵浦功率最大为1.6 W时,计算扣除输入端光纤与波导的耦合损耗后的输入泵浦功率为1.2 W,光纤到波导的耦合效率为75%,略高于当前已知的最高效率72%。1 560 nm基频光的输入功率为1.2 W时,最大输出653 mW的倍频光,光光转换效率达到了54.4%,归一化转换效率为20.2%/(W·cm²)。

关键词: 光纤, 周期性极化铌酸锂, 波导, 端面耦合, 耦合效率

Abstract: The feasibility of achieving efficient coupling between an optical fiber and a periodically poled lithium niobate (PPLN) waveguide in an ideal optical system was theoretically analyzed using a finite element simulator. Divergence of single-mode polarization-maintaining fiber and lensed fiber in space was simulated. Direct end-face coupling simulations were conducted for a PPLN ridge waveguide with a cross-sectional size of 10 μm×10 μm and a length of 20 mm, involving two different types of fibers. It is found that despite the lensed fiber achieving a coupling efficiency of up to 95%, its fundamental mode contribution is less than 5%. Given that PPLN frequency-doubling devices primarily rely on the laser’s fundamental mode for operation, this renders the coupling efficiency of the lensed fiber relatively low in practical applications. In contrast, ordinary single-mode fiber exhibits a significantly higher fundamental mode contribution of 93.8%, demonstrating its superior performance. Therefore, this study selects ordinary single-mode fiber for encapsulation testing with PPLN ridge waveguides. The experimental results show that when the maximum pump power output from the fiber amplifier reaches 1.6 W, the calculated input pump power, after deducting the coupling losses between the input fiber and the waveguide, stands at 1.2 W. The fiber-to-waveguide coupling efficiency is 75%, slightly exceeding the currently known advanced value of 72%. At a temperature of 24.8 ℃, with an input power of 1.2 W at the fundamental wavelength of 1 560 nm, the maximum output of frequency-doubled light is 653 mW. The optical-to-optical conversion efficiency reaches 54.4%, with a normalized conversion efficiency of 20.2%/(W·cm²).

Key words: fiber, periodically poled lithium niobate, waveguide, end-face coupling, coupling efficiency

中图分类号:

TN814

马翠坪, 陈家颖, 陈怀熹, 梁万国, 伍秋林, 冯新凯. 光纤端面耦合周期极化铌酸锂(PPLN)薄膜波导器件的研究[J]. 人工晶体学报, 2024, 53(8): 1319-1325.

MA Cuiping, CHEN Jiaying, CHEN Huaixi, LIANG Wanguo, WU Qiulin, FENG Xinkai. Study on Fiber End-Face Coupled Periodically Poled Lithium Niobate (PPLN) Thin Film Waveguide Device[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2024, 53(8): 1319-1325.

参考文献

[1] 孙军, 郝永鑫, 张玲, 等. 铌酸锂晶体及其应用概述[J]. 人工晶体学报, 2020, 49(6): 947-964.
SUN J, HAO Y X, ZHANG L, et al. Brief review of lithium niobate crystal and its applications[J]. Journal of Synthetic Crystals, 2020, 49(6): 947-964 (in Chinese).
[2] NIU Y R, YAN X, CHEN J X, et al. Research progress on periodically poled lithium niobate for nonlinear frequency conversion[J]. Infrared Physics and Technology, 2022, 125: 104243.
[3] LIU J, DUAN Y M, LI Z H, et al. Recent progress in nonlinear frequency conversion of optical vortex lasers[J]. Frontiers in Physics, 2022, 10: 865029.
[4] POBERAJ G, HU H, SOHLER W, et al. Lithium niobate on insulator (LNOI) for micro-photonic devices[J]. Laser & Photonics Reviews, 2012, 6(4): 488-503.
[5] BOES A, CORCORAN B, CHANG L, et al. Status and potential of lithium niobate on insulator (LNOI) for photonic integrated circuits[J]. Laser & Photonics Reviews, 2018, 12(4): 1700256.
[6] LUO R, JIANG H W, ROGERS S, et al. On-chip second-harmonic generation and broadband parametric down-conversion in a lithium niobate microresonator[J]. Optics Express, 2017, 25(20): 24531-24539.
[7] LUO R, JIANG H W, LIANG H X, et al. Self-referenced temperature sensing with a lithium niobate microdisk resonator[J]. Optics Letters, 2017, 42(7): 1281-1284.
[8] MERCANTE A J, YAO P, SHI S Y, et al. 110 GHz CMOS compatible thin film LiNbO₃ modulator on silicon[J]. Optics Express, 2016, 24(14): 15590-15595.
[9] SOLTANI M, ZHANG M, RYAN C, et al. Efficient quantum microwave-to-optical conversion using electro-optic nanophotonic coupled resonators[J]. Physical Review A, 2017, 96(4): 043808.
[10] JAVERZAC-GALY C, PLEKHANOV K, BERNIER N R, et al. On-chip microwave-to-optical quantum coherent converter based on a superconducting resonator coupled to an electro-optic microresonator[J]. Physical Review A, 2016, 94(5): 053815.
[11] HE L Y, ZHANG M, SHAMS-ANSARI A, et al. Low-loss fiber-to-chip interface for lithium niobate photonic integrated circuits[J]. Optics Letters, 2019, 44(9): 2314-2317.
[12] KAR A, BAHADORI M, GONG S B, et al. Realization of alignment-tolerant grating couplers for z-cut thin-film lithium niobate[J]. Optics Express, 2019, 27(11): 15856-15867.
[13] CHANG L, LI Y F, VOLET N, et al. Thin film wavelength converters for photonic integrated circuits[J]. Optica, 2016, 3(5): 531.
[14] CAI L T, PIAZZA G. Low-loss chirped grating for vertical light coupling in lithium niobate on insulator[J]. Journal of Optics, 2019, 21(6): 065801.
[15] LIU D N, FENG L S, JIA Y Z, et al. Heterogeneous integration of LN and Si₃N₄ waveguides using an optical interlayer coupler[J]. Optics Communications, 2019, 436: 1-6.
[16] TAILLAERT D, VAN LAERE F, AYRE M, et al. Grating couplers for coupling between optical fibers and nanophotonic waveguides[J]. Japanese Journal of Applied Physics, 2006, 45(8A): 6071.
[17] MEKIS A, GLOECKNER S, MASINI G, et al. A grating-coupler-enabled CMOS photonics platform[J]. IEEE Journal of Selected Topics in Quantum Electronics, 2011, 17(3): 597-608.
[18] DING Y H, PEUCHERET C, OU H Y, et al. Fully etched apodized grating coupler on the SOI platform with-0.58 dB coupling efficiency[J]. Optics Letters, 2014, 39(18): 5348-5350.
[19] BENEDIKOVIC D, CHEBEN P, SCHMID J H, et al. Subwavelength index engineered surface grating coupler with sub-decibel efficiency for 220-nm silicon-on-insulator waveguides[J]. Optics Express, 2015, 23(17): 22628-22635.
[20] XU Y, XIAO J B. Compact and high extinction ratio polarization beam splitter using subwavelength grating couplers[J]. Optics Letters, 2016, 41(4): 773-776.
[21] KRASNOKUTSKA I, CHAPMAN R J, TAMBASCO J L J, et al. High coupling efficiency grating couplers on lithium niobate on insulator[J]. Optics Express, 2019, 27(13): 17681-17685.
[22] 冯新凯, 陈怀熹, 陈家颖, 等. 光纤耦合周期极化铌酸锂薄膜波导器件的研究[J]. 中国激光, 2023, 50(22): 3788/CJL230448.
FENG X K, CHEN H X, CHEN J Y, et al. Study of fiber-coupled periodically poled lithium niobate thin film waveguide devices[J]. Chinese Journal of Lasers, 2023, 50(22): 3788/CJL230448 (in Chinese).
[23] KANG S T, ZHANG R, HAO Z Z, et al. High-efficiency chirped grating couplers on lithium niobate on insulator[J]. Optics Letters, 2020, 45(24): 6651-6654.