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对于光子的局域, 在基础研究和技术应用领域具有重要意义. 光子晶体中的连续域中的束缚态(bound states in the continuum, BICs)为光子的局域提供了新的机制. 然而光子晶体在制备过程中会不可避免地引入误差和缺陷, 动量空间表征可以分析加工误差和缺陷对于光子晶体能带特性的影响, 进而指导光子晶体器件的设计和制备. 本文设计了可见光波段的光子晶体, 通过动量空间表征观测到了连续域中的准束缚态(quasi-BIC), 从而在垂直方向上实现了对光子的有效局域, 并通过调整结构参数, 实现了对光子晶体动量空间的特征调控. 进一步设计不同周期光子晶体的横向异质结构, 利用两者的能带套嵌实现了对光子的横向局域, 以此制备品质因子与模式体积之比达到6 × 1014 cm–3的高品质微腔. 本研究对于光子晶体的设计以及增强光与物质相互作用具有重要意义.Photon localization is of great significance in both basic research and technical applications. Bound states in the continuum (BICs) in photonic crystal provide a new mechanism for effective photon localization. However, the imperfections and defects are inevitable in the process of fabricating photonic crystals. Momentum-space characterization is used as a powerful tool to analyze how such processing variations affect the photonic band structure, providing information for designing and fabricating photonic crystal devices. In this work, a photonic crystal in the visible light band is designed and its band structure is analyzed through FDTD simulation. The high symmetry at the point in momentum space Γ leads to a symmetry mismatch between the internal mode of the photonic crystal and the external propagation mode (radiation continuum), so that bound states with infinite lifetime appear above the light, thereby achieving the localization of photons in the vertical direction. At the same time, the angle-resolved photoluminescence (PL) spectrum of the photonic crystal is measured through the self-built angle-resolved optical path. The weak photoluminescence of the Si3N4 substrate is coupled with the photonic crystal mode for measuring the photonic crystal band. It can be observed that the band structure is consistent with the simulation results. At the same time, the intensity of the TE1 band near the Γ point is significantly weakened compared with the intensity at the position away from the Γ point, but it is not completely eliminated. This shows that errors and defects caused in fabrication process will destroy the symmetry of the structure, causing the BIC to evolve into the quasi-BIC. The quasi-BIC mode achieves effective localization of photons in the vertical direction near the Γ point. Furthermore, a heterostructure of photonic crystals with different periods is designed to achieve lateral photon localization by utilizing the band nesting between the two]. Through this approach, this study ultimately develops a high-quality microcavity with a ratio of impressive quality factor to mode volume of $ 6\times {10}^{14} $ cm–3, and achieves characteristic regulation of the momentum space of photonic crystals by adjusting the structural parameters. This research is of great significance for designing photonic crystals and studying the interaction between light and matter.
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Keywords:
- photonic crystals /
- bound states in the continuation domain /
- momentum space /
- visible wavelengths
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图 1 光子晶体的设计和制备 (a) 光子晶体及导致其损耗因素的示意图; (b) 模拟的能带结构, 其中红色圆点代表TE模式, 蓝色圆点代表TM模式, 插图为第一个布里渊区; (c) 制备的光子晶体局部的扫描电子显微镜俯视图, 周期为326 nm, 孔洞结构直径为223 nm; (d) 制备的光子晶体扫描电子显微镜侧视图, 其中孔洞结构的高度为365 nm; (e) 光子晶体的扫描电子显微镜图像
Fig. 1. Design and fabrication of photonic crystal: (a) Schematic of a photonic crystal and the factors contributing to loss. (b) Simulated band structure. The TE band is marked with red dots and The TM band is marked with blue dots. Inset: the first Brillouin zone. (c) Scanning electron microscope images of the fabricated photonic crystal from top views. The period is 326 nm and the diameter of the cylindrical holes is 223 nm. (d) Scanning electron microscope images of the fabricated photonic crystal from side views. The height of the cylindrical holes is 365 nm; (e) Scanning electron microscope images of the fabricated photonic crystal.
图 2 光子晶体动量空间表征 (a) 角分辨光路原理示意图, 其中绿色线代表激发光, 浅红色线代表样品光致荧光信号, “BFP”表示后焦面; (b) 沿Γ-X方向和(d)沿Γ-M方向的角分辨光致荧光光谱; (c) 沿Γ-X方向和(e)沿Γ-M方向能带仿真. 光子晶体结构参数如图1(c), (d)所示
Fig. 2. Characterization of momentum in photonic crystal: (a) Schematic of angle-resolved optical path. The green lines represent the incident light. The light red region denotes photoluminescence signal. BFP, back focal plane. (b), (d) Measured angle-resolved photoluminescence (PL) spectra along Γ-X (b) and Γ-M (d) directions. (c), (e) Calculated band structure along Γ-X (c) and Γ-M (e) directions. The structure parameters of photonic crystal are shown in Fig. 1 (c) and Fig. 1 (d).
图 3 微腔的模式表征 (a) 微腔SEM图像, A区域光子晶体(周期 a = 325 nm, 直径d = 214 nm, 孔洞数目$ {N}_{a} $ = 13)由不同周期的B区域光子晶体(周期b = 335 nm, 直径d = 214 nm, 孔洞数目$ {N}_{b} $ = 17)包围, 两区域之间的间隔为330 nm; (b) 光子晶体PL光谱; (c) 光子晶体的模式热点位置处的PL光谱; (d) 光子晶体的PL扫描图像; (e) M11模式、(f) M12模式和(g) M21模式的远场模式分布; 白色虚线和蓝色虚线分别表示A区域和B区域光子晶体边界; 黄色虚线表示模式表征的扫描区域
Fig. 3. Characterization of micro-cavity modes: (a) SEM image of micro-cavity. Region A photonic crystal (period a = 325 nm, diameter d = 214 nm, the number of holes $ {N}_{\mathrm{a}} $ = 13) are surrounded by region B photonic crystal (period b = 335 nm, diameter d = 214 nm, the number of holes $ {N}_{\mathrm{b}} $ = 17) with different periods, and the interval between the two regions is 330 nm. (b) PL spectral of photonic crystal. (c) PL spectral of mode hot spot in photonic crystal. (d) PL mapping image of photonic crystal. The far-field distribution of (e) M11, (f) M12 and (g) M21 modes. The white dashed and blue dashed represent the photonic crystal boundaries of region A and region B respectively. The yellow dashed represents the scan area of the mode characterization.
图 4 微腔的参数调控 (a) 孔洞直径d为214 nm和(b) 229 nm的光子晶体角分辨PL光谱; (c) 不同孔洞直径的微腔光子晶体A区域PL光谱; (d) 高度h为330 nm, 孔洞直径d为233 nm的光子晶体角分辨PL光谱; (e) 高度h为330 nm不同孔洞直径的微腔光子晶体A区域PL光谱; (f) 高度h为330 nm孔洞直径d为233 nm的光子晶体PL扫描图像, 白色虚线和蓝色虚线分别表示A区域和B区域光子晶体边界; 图4样品的其他结构参数均与图3(a)相同
Fig. 4. Parameters tuning of micro-cavity: Measured angle-resolved PL spectra of photonic crystals with hole diameter d of (a) 214 nm and (b) 229 nm; (c) PL spectra of region A of microcavity photonic crystals with different hole diameters; (d) measured angle-resolved PL spectra of photonic crystals with height h of 330 nm and hole diameter d of 233 nm; (e) PL spectra of region A of microcavity photonic crystals with different hole diameters and a height h of 330 nm; (f) PL mapping image of photonic crystals with height h of 330 nm and hole diameter d of 233 nm. The white dashed and blue dashed represent the photonic crystal boundaries of region A and region B respectively. Other structural parameters of the sample in Fig. 4 are the same as those in Fig. 3(a).
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[1] Genack A Z, Garcia N 1991 Phys. Rev. Lett. 66 2064
Google Scholar
[2] von Neumann J, Wigner E P. 1929 Phys. Z. 30 465
[3] Fan S, Joannopoulos J D 2002 Phys. Rev. B 65 235112
Google Scholar
[4] Gomis-Bresco J, Artigas D, Torner L 2017 Nat. Photonics 11 232
Google Scholar
[5] Plotnik Y, Peleg O, Dreisow F, Heinrich M, Nolte S, Szameit A, Segev M 2011 Phys. Rev. Lett. 107 183901
Google Scholar
[6] Friedrich H, Wintgen D 1985 Phys. Rev. A 32 3231
Google Scholar
[7] Zhang J M, Braak D, Kollar M 2012 Phys. Rev. Lett. 109 116405
Google Scholar
[8] Lim T C, Farnell G W 1969 J. Acoust. Soc. Am. 45 845
Google Scholar
[9] Porter R, Evans D V 2005 Wave Motion 43 29
Google Scholar
[10] Joannopoulos J D, Villeneuve P R, Fan S 1997 Nature 386 143
Google Scholar
[11] Tang G J, He X T, Shi F L, Liu J W, Chen X D, Dong J W 2022 Laser Photonics Rev. 16 2100300
Google Scholar
[12] Hsu C W, Zhen B, Lee J, Chua S L, Johnson S G, Joannopoulos J D, Soljačić M 2013 Nature 499 188
Google Scholar
[13] Jin J, Yin X, Ni L, Soljačić M, Zhen B, Peng C 2019 Nature 574 501
Google Scholar
[14] Marinica D C, Borisov A G, Shabanov S V 2008 Phys. Rev. Lett. 100 183902
Google Scholar
[15] Molina M I, Miroshnichenko A E, Kivshar Y S 2012 Phys. Rev. Lett. 108 070401
Google Scholar
[16] Hirose K, Liang Y, Kurosaka Y, Watanabe A, Sugiyama T, Noda S 2014 Nat. Photonics 8 406
Google Scholar
[17] Kodigala A, Lepetit T, Gu Q, Bahari B, Fainman Y, Kanté B 2017 Nature 541 196
Google Scholar
[18] Hwang M S, Lee H C, Kim K H, Jeong K Y, Kwon S H, Koshelev K, Kivshar Y, Park H G 2021 Nat. Commun. 12 4135
Google Scholar
[19] 闫梦, 孙珂, 宁廷银, 赵丽娜, 任莹莹, 霍燕燕 2023 物理学报 72 044202
Google Scholar
Yan M, Sun K, Ning T Y, Zhao L N, Ren Y Y, Huo Y Y 2023 Acta Phys. Sin. 72 044202
Google Scholar
[20] Iwahashi S, Kurosaka Y, Sakai K, Kitamura K, Takayama N, Noda S 2011 Opt. Express 19 11963
Google Scholar
[21] Kitamura K, Sakai K, Takayama N, Nishimoto M, Noda S 2012 Opt. Lett. 37 2421
Google Scholar
[22] Yang J L, Shi A Q, Peng Y C, Peng P, Liu J J 2024 Chin. Phys. B 33 306
[23] Koshelev K, Lepeshov S, Liu M, Bogdanov A, Kivshar Y 2018 Phys. Rev. Lett. 121 193903
Google Scholar
[24] Wang D, Xiong A Y, Zhang J Q, She Z D, Kang X F, Zhu Y, Ghosh S, Xiong Q H 2024 Chin. Phys. B 33 197
[25] 夏兆生, 刘宇行, 包正, 王丽华, 吴博, 王刚, 王辉, 任信钢, 黄志祥 2024 物理学报 73 178102
Google Scholar
Xiao Z S, Liu Y X, Bao Z, Wang L H, Wu B, Wang G, Wang H, Ren X G, Huang Z X 2024 Acta Phys. Sin. 73 178102
Google Scholar
[26] Wu F, Wu J, Guo Z, Jiang H, Sun Y, Li Y, Ren J, Chen H, 2019 Phys. Rev. Appl. 12 014028
Google Scholar
[27] Wu F, Qi X, Qin M, Luo M, Long Y, Wu J, Sun Y, Jiang H, Liu T, Xiao S, Chen H 2024 Phys. Rev. B 109 085436
Google Scholar
[28] Wei M, Long Y, Wu F, Liu G G, Zhang B 2025 Sci. Bull. 70 882
Google Scholar
[29] Zhen B, Hsu C W, Lu L, Stone A D, Soljačić M 2014 Phys. Rev. Lett. 113 257401
Google Scholar
[30] Men H, Lee K Y K, Freund R M, Peraire J, Johnson S G 2014 Opt. Express 22 2263
[31] Lee J, Zhen B, Chua S L, Qiu W, Joannopoulos J D, Soljačić M, Shapira O 2012 Phys. Rev. Lett. 109 067401
Google Scholar
[32] Perczel J, Borregaard J, Chang D E, Yelin S F, Lukin M D 2020 Phys. Rev. Lett. 124 083603
Google Scholar
[33] Ge X, Minkov M, Fan S, Li X, Zhou W 2019 npj 2D Mater. Appl. 3 16
[34] Wu M, Ding L, Sabatini R P, Sagar L K, Bappi G, Paniagua-Domínguez R, Sargent E H, Kuznetsov A I 2021 Nano Lett. 21 9754
Google Scholar
[35] Sun S, Kim H, Luo Z, Solomon G S, Waks E 2018 Science 361 57
Google Scholar
[36] Carletti L, Koshelev K, De Angelis C, Kivshar Y 2018 Phys. Rev. Lett. 121 033903
Google Scholar
[37] Bernhardt N, Koshelev K, White S J U, Meng K W C, Fröch J E, Kim S, Tran T T, Choi D Y, Kivshar Y, Solntsev A S 2020 Nano Lett. 20 5309
Google Scholar
[38] Chen Z H, Yin X F, Jin J C, Zheng Z, Zhang Z X, Wang F F, He L, Zhen B, Peng C 2022 Sci. Bull. 67 359
Google Scholar
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