[1] M. Schmeltz, C. Teulon, M. Pinsard. Circular dichroism second-harmonic generation microscopy probes the polarity distribution of collagen fibrils. Optica, 7, 1469-1476(2020).

[2] I. Freund, M. Deutsch. Second-harmonic microscopy of biological tissue. Opt. Lett., 11, 94-96(1986).

[3] J. Volz, A. S. Prasad, J. Hinney. Correlating photons using the collective nonlinear response of atoms weakly coupled to an optical mode. Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, ea_1_3(2021).

[4] J. D. Cox, I. Silveiro, F. J. García de Abajo. Quantum effects in the nonlinear response of graphene plasmons. ACS Nano, 10, 1995-2003(2016).

[5] R. Yi, X. Zhang, C. Li. Self-frequency-conversion nanowire lasers. Light Sci. Appl., 11, 120(2022).

[6] C. B. de Araújo, A. S. L. Gomes, G. Boudebs. Techniques for nonlinear optical characterization of materials: a review. Rep. Prog. Phys., 79, 036401(2016).

[7] J. C. Johnson, H. Yan, R. D. Schaller. Near-field imaging of nonlinear optical mixing in single zinc oxide nanowires. Nano Lett., 2, 279-283(2002).

[8] Y. Liu, X. Liu, S. Liu. An unprecedented antimony III. Borate with strong linear and nonlinear optical responses. Angew. Chem. Int. Ed., 59, 7793-7796(2020).

[9] Y. Zhou, Y. Huang, X. Xu. Nonlinear optical properties of halide perovskites and their applications. Appl. Phys. Rev., 7, 041313(2020).

[10] G. I. Stegeman, G. Assanto. Nonlinear integrated optical devices. Integrated Optical Circuits and Components(1999).

[11] S.-Y. Zhang, X. Shu, Y. Zeng. Molecule-based nonlinear optical switch with highly tunable on-off temperature using a dual solid solution approach. Nat. Commun., 11, 2752(2020).

[12] C. Guo, J. Yu, S. Deng. Hybrid metasurfaces of plasmonic lattices and 2D materials. Adv. Funct. Mater., 33, 2302265(2023).

[13] T. Zhang, Q. Guo, Z. Shi. Coherent second harmonic generation enhanced by coherent plasmon–exciton coupling in plasmonic nanocavities. ACS Photonics, 10, 1529-1537(2023).

[14] L. Qu, Z. Gu, C. Li. Bright second harmonic emission from photonic crystal vertical cavity. Adv. Funct. Mater., 33, 2308484(2023).

[15] H. Kim, B.-S. Song, T. Asano. Enhanced second-harmonic generation in a photonic crystal waveguide-coupled nanocavity using a wavelength-selective reflector. APL Photonics, 8, 121303(2023).

[16] F. Torresi, J. Lasave, S. Koval. Path integral Monte Carlo simulations of the geometrical effects in KDP crystals. Condens. Matter Phys., 25, 43708(2022).

[17] X. Li, J. Ma, S. Liu. Efficient second harmonic generation by harnessing bound states in the continuum in semi-nonlinear etchless lithium niobate waveguides. Light Sci. Appl., 11, 317(2022).

[18] T. Abir, M. Tal, T. Ellenbogen. Second-harmonic enhancement from a nonlinear plasmonic metasurface coupled to an optical waveguide. Nano Lett., 22, 2712-2717(2022).

[19] M. Celebrano, X. Wu, M. Baselli. Mode matching in multiresonant plasmonic nanoantennas for enhanced second harmonic generation. Nat. Nanotechnol., 10, 412-417(2015).

[20] G.-C. Li, D. Lei, M. Qiu. Light-induced symmetry breaking for enhancing second-harmonic generation from an ultrathin plasmonic nanocavity. Nat. Commun., 12, 4326(2021).

[21] A. Noor, A. R. Damodaran, I.-H. Lee. Mode-matching enhancement of second-harmonic generation with plasmonic nanopatch antennas. ACS Photonics, 7, 3333-3340(2020).

[22] N. Bernhardt, K. Koshelev, S. J. U. White. Quasi-BIC resonant enhancement of second-harmonic generation in WS₂ monolayers. Nano Lett., 20, 5309-5314(2020).

[23] J. Deng, Y. Tang, S. Chen. Giant enhancement of second-order nonlinearity of epsilon-near-zero medium by a plasmonic metasurface. Nano Lett., 20, 5421-5427(2020).

[24] R. F. Ali, J. A. Busche, S. Kamal. Near-field enhancement of optical second harmonic generation in hybrid gold-lithium niobate nanostructures. arXiv(2022).

[25] A. Fedotova, M. Younesi, J. Sautter. Second-harmonic generation in resonant nonlinear metasurfaces based on lithium niobate. Nano Lett., 20, 8608-8614(2020).

[26] Y. Ren, X. Zhao, E. W. Hagley. Ambient-condition growth of high-pressure phase centrosymmetric crystalline KDP microstructures for optical second harmonic generation. Sci. Adv., 2, e1600404(2016).

[27] M. Zhang, N. Han, J. Zhang. Emergent second-harmonic generation in van der Waals heterostructure of bilayer MoS₂ and monolayer graphene. Sci. Adv., 9, eadf4571(2023).

[28] Q. Yuan, L. Fang, H. Fang. Second harmonic and sum-frequency generations from a silicon metasurface integrated with a two-dimensional material. ACS Photonics, 6, 2252-2259(2019).

[29] Y. Song, R. Tian, J. Yang. Second harmonic generation in atomically thin MoTe₂. Adv. Opt. Mater., 6, 1701334(2018).

[30] Y. Song, S. Hu, M.-L. Lin. Extraordinary second harmonic generation in ReS₂ atomic crystals. ACS Photonics, 5, 3485-3491(2018).

[31] B. Wang, Y. Ji, L. Gu. High-efficiency second-harmonic and sum-frequency generation in a silicon nitride microring integrated with few-layer GaSe. ACS Photonics, 9, 1671-1678(2022).

[32] B. Jiang, Z. Hao, Y. Ji. High-efficiency second-order nonlinear processes in an optical microfibre assisted by few-layer GaSe. Light Sci. Appl., 9, 63(2020).

[33] J. Zhang, W. Zhao, P. Yu. Second harmonic generation in 2D layered materials. 2D Mater., 7, 042002(2020).

[34] R.-M. Ma, H.-Y. Luan, Z.-W. Zhao. Twisted lattice nanocavity with theoretical quality factor exceeding 200 billion. Fundam. Res, 3, 537-543(2023).

[35] X.-R. Mao, Z.-K. Shao, H.-Y. Luan. Magic-angle lasers in nanostructured moiré superlattice. Nat. Nanotechnol., 16, 1099-1105(2021).

[36] A. Raun, H. Tang, X. Ni. GaN magic angle laser in a merged moiré photonic crystal. ACS Photonics, 10, 3001-3007(2023).

[37] Z. Zhang, D. Liu, Y. Huo. Ultralow-level all-optical self-switching in a nanostructured moiré superlattice. Opt. Lett., 47, 5260-5263(2022).

[38] Q. Fu, P. Wang, C. Huang. Optical soliton formation controlled by angle twisting in photonic moiré lattices. Nat. Photonics, 14, 663-668(2020).

[39] W. Wang, Y. Srivastava, T. Tan. Brillouin zone folding driven bound states in the continuum. Nat. Commun., 14, 2811(2023).

[40] M. Farhat, Y. Achaoui, J. A. I. Martinez. Observation of ultra-high-Q resonators in the ultrasound via bound states in the continuum. Adv. Sci., 11, 2402917(2024).

[41] S. Liu, H. Tong, K. Fang. Optomechanical crystal with bound states in the continuum. Nat. Commun., 13, 3187(2022).

[42] G. Plechinger, J. Mann, E. Preciado. A direct comparison of CVD-grown and exfoliated MoS₂ using optical spectroscopy. Semicond. Sci. Technol., 29, 064008(2014).

[43] D. J. Clark, V. Senthilkumar, C. T. Le. Strong optical nonlinearity of CVD-grown MoS₂ monolayer as probed by wavelength-dependent second-harmonic generation. Phys. Rev. B, 90, 121409(2014).

[44] Y. Li, Y. Rao, K. F. Mak. Probing symmetry properties of few-layer MoS₂ and h-BN by optical second-harmonic generation. Nano Lett., 13, 3329-3333(2013).

[45] T. Stiehm, R. Schneider, J. Kern. Supercontinuum second harmonic generation spectroscopy of atomically thin semiconductors. Rev. Sci. Instrum., 90, 083102(2019).

[46] H. G. Rosa, Y. W. Ho, I. Verzhbitskiy. Characterization of the second- and third-harmonic optical susceptibilities of atomically thin tungsten diselenide. Sci. Rep., 8, 10035(2018).

[47] L. Karvonen, A. Säynätjoki, S. Mehravar. Investigation of second- and third-harmonic generation in few-layer gallium selenide by multiphoton microscopy. Sci. Rep., 5, 10334(2015).

[48] A. R. Khan, L. Zhang, K. Ishfaq. Optical harmonic generation in 2D materials. Adv. Funct. Mater., 32, 2105259(2022).

[49] A. A. Popkova, I. M. Antropov, J. E. Fröch. Optical third-harmonic generation in hexagonal boron nitride thin films. ACS Photonics, 8, 824-831(2021).

[50] A. Autere, H. Jussila, A. Marini. Optical harmonic generation in monolayer group-VI transition metal dichalcogenides. Phys. Rev. B, 98, 115426(2018).

[51] Y. Tang, K. C. Mandal, J. A. McGuire. Layer- and frequency-dependent second harmonic generation in reflection from GaSe atomic crystals. Phys. Rev. B, 94, 125302(2016).

[52] X. Gan, C. Zhao, S. Hu. Microwatts continuous-wave pumped second harmonic generation in few- and mono-layer GaSe. Light Sci. Appl, 7, 17126(2018).

[53] Y. Zhong, S. Yue, J. Liang. Twist angle-dependent exciton mobility in WS₂ bilayers. Nano Lett., 25, 5274-5282(2025).