[1] [1] Shen Y R. The Principles of Nonlinear Optics[M]. New Yk: Wiley, 1984.

[2] [2] Boyd R W. Nonlinear Optics[M]. New Yk: Academic, 2008.

[3] J A Armstrong, N Bloembergen, J Ducuing. Interactions between light waves in a nonlinear dielectric. Physical Review, 127, 1918-1939(1962).

[4] M M Fejer, G A Magel, D H Jundt. Quasi-phase-matched 2nd harmonic-generation-tuning and tolerances. IEEE Journal of Quantum Electronics, 28, 2631-2654(1992).

[5] M Yamada, N Nada, M Saitoh. First‐order quasi‐phase matched linbo₃ waveguide periodically poled by applying an external field for efficient blue second‐harmonic generation. Applied Physics Letters, 62, 435-436(1993).

[6] L E Myers, R C Eckardt, M M Fejer. Quasi-phase-matched optical parametric oscillators in bulk periodically poled LiNbO₃. Journal of the Optical Society of America B-Optical Physics, 12, 2102-2116(1995).

[7] A V Kildishev, A Boltasseva, V M Shalaev. Planar photonics with metasurfaces. Science, 339, 1232009(2013).

[8] N Meinzer, W L Barnes, I R Hooper. Plasmonic meta-atoms and metasurfaces. Nature Photonics, 8, 889-898(2014).

[9] N F Yu, F Capasso. Flat optics with designer metasurfaces. Nature Materials, 13, 139-150(2014).

[10] M W Klein, C Enkrich, M Wegener. Second-harmonic generation from magnetic metamaterials. Science, 313, 502-504(2006).

[11] V K Valev, N Smisdom, A V Silhanek. Plasmonic ratchet wheels: Switching circular dichroism by arranging chiral nanostructures. Nano Letters, 9, 3945-3948(2009).

[12] H Husu, R Siikanen, J Makitalo. Metamaterials with tailored nonlinear optical response. Nano Letters, 12, 673-677(2012).

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

[14] L Gui, S Bagheri, N Strohfeldt. Nonlinear refractory plasmonics with titanium nitride nanoantennas. Nano Letters, 16, 5708-5713(2016).

[15] S Liu, M B Sinclair, S Saravi. Resonantly enhanced second-harmonic generation using iii-v semiconductor all-dielectric metasurfaces. Nano Letters, 16, 5426-5432(2016).

[16] P P Vabishchevich, S Liu, M B Sinclair. Enhanced second-harmonic generation using broken symmetry iii–v semiconductor fano metasurfaces. ACS Photonics, 5, 1685-1690(2018).

[17] K Koshelev, S Kruk, E Melik-Gaykazyan. Subwavelength dielectric resonators for nonlinear nanophotonics. Science, 367, 288-292(2020).

[18] J Lee, M Tymchenko, C Argyropoulos. Giant nonlinear response from plasmonic metasurfaces coupled to intersubband transitions. Nature, 511, 65-69(2014).

[19] J Lee, N Nookala, J S Gomez‐Diaz. Ultrathin second‐harmonic metasurfaces with record-high nonlinear optical response. Advanced Optical Materials, 4, 664-670(2016).

[20] L Kang, Y H Cui, S F Lan. Electrifying photonic metamaterials for tunable nonlinear optics. Nature Communications, 5, 4680(2014).

[21] K-T Lee, M Taghinejad, J Yan. Electrically biased silicon metasurfaces with magnetic mie sesonance for tunable harmonic generation of light. ACS Photonics, 6, 2663-2670(2019).

[22] M W Klein, M Wegener, N Feth. Experiments on second- and third-harmonic generation from magnetic metamaterials. Opt Express, 15, 5238-5247(2007).

[23] M Hentschel, T Utikal, H Giessen. Quantitative modeling of the third harmonic emission spectrum of plasmonic nanoantennas. Nano Letters, 12, 3778-3782(2012).

[24] B Metzger, T Schumacher, M Hentschel. Third harmonic mechanism in complex plasmonic fano structures. ACS Photonics, 1, 471-476(2014).

[25] M R Shcherbakov, D N Neshev, B Hopkins. Enhanced third-harmonic generation in silicon nanoparticles driven by magnetic response. Nano Letters, 14, 6488-6492(2014).

[26] Y Yang, W Wang, A Boulesbaa. Nonlinear fano-resonant dielectric metasurfaces. Nano Lett, 15, 7388-7393(2015).

[27] T Shibanuma, G Grinblat, P Albella. Efficient third harmonic generation from metal-dielectric hybrid nanoantennas. Nano Lett, 17, 2647-2651(2017).

[28] L Xu, M Rahmani, Kamali K Zangeneh. Boosting third-harmonic generation by a mirror-enhanced anapole resonator. Light Sci Appl, 7, 44(2018).

[29] K Koshelev, Y Tang, K Li. Nonlinear metasurfaces governed by bound states in the continuum. ACS Photonics, 6, 1639-1644(2019).

[30] Z Liu, Y Xu, Y Lin. High-Q quasibound states in the continuum for nonlinear metasurfaces. Physical Review Letters, 123, 253901(2019).

[31] F Krausz, M Ivanov. Attosecond physics. Reviews of Modern Physics, 81, 163-234(2009).

[32] P B Corkum, F Krausz. Attosecond science. Nature Physics, 3, 381-387(2007).

[33] A Stolow, A E Bragg, D M Neumark. Femtosecond time-resolved photoelectron spectroscopy. Chemical Reviews, 104, 1719-1757(2004).

[34] A L Cavalieri, N Mueller, T Uphues. Attosecond spectroscopy in condensed matter. Nature, 449, 1029-1032(2007).

[35] R He, Z S Lin, T Zheng. Energy band gap engineering in borate ultraviolet nonlinear optical crystals: Ab initio studies. Journal of Physics-Condensed Matter, 24, 145503(2012).

[36] M Wu, S Ghimire, D A Reis. High-harmonic generation from bloch electrons in solids. Physical Review A, 91, 043839(2015).

[37] S Ghimire, D A Reis. High-harmonic generation from solids. Nature Physics, 15, 10-16(2019).

[38] S Kim, J Jin, Y-J Kim. High-harmonic generation by resonant plasmon field enhancement. Nature, 453, 757-760(2008).

[39] M Sivis, M Duwe, B Abel. Extreme-ultraviolet light generation in plasmonic nanostructures. Nature Physics, 9, 304-309(2013).

[40] S Han, H Kim, Y W Kim. High-harmonic generation by field enhanced femtosecond pulses in metal-sapphire nanostructure. Nature Communications, 7, 13105(2016).

[41] G Vampa, B G Ghamsari, Mousavi S Siadat. Plasmon-enhanced high-harmonic generation from silicon. Nature Physics, 13, 659-662(2017).

[42] H Liu, C Guo, G Vampa. Enhanced high-harmonic generation from an all-dielectric metasurface. Nature Physics, 14, 1006-1010(2018).

[43] S Liu, P P Vabishchevich, A Vaskin. An all-dielectric metasurface as a broadband optical frequency mixer. Nature Communications, 9, 2507(2018).

[44] [44] Zhang X C, Xu J. Introduction to THz Wave Photonics[M]. New Yk: Springer, 2010.

[45] A Nahata, A S Weling, T F Heinz. A wideband coherent terahertz spectroscopy system using optical rectification and electro-optic sampling. Applied Physics Letters, 69, 2321-2323(1996).

[46] Q Wu, M Litz, X C Zhang. Broadband detection capability of znte electro-optic field detectors. Applied Physics Letters, 68, 2924-2926(1996).

[47] K L Yeh, M C Hoffmann, J Hebling. Generation of 10 μJ ultrashort terahertz pulses by optical rectification. Applied Physics Letters, 90, 171121(2007).

[48] F Blanchard, G Sharma, L Razzari. Generation of intense terahertz radiation via optical methods. IEEE Journal of Selected Topics in Quantum Electronics, 17, 5-16(2011).

[49] M Tani, R Fukasawa, H Abe. Terahertz radiation from coherent phonons excited in semiconductors. Journal of Applied Physics, 83, 2473-2477(1998).

[50] L Luo, I Chatzakis, J Wang. Broadband terahertz generation from metamaterials. Nature Communications, 5, 3055(2014).

[51] M Fang, K Niu, Z Huang. Investigation of broadband terahertz generation from metasurface. Opt Express, 26, 14241-14250(2018).

[52] M V Berry. Quantal phase-factors accompanying adiabatic changes. Proceedings of the Royal Society of London Series a-Mathematical and Physical Sciences, 392, 45-57(1984).

[53] S Pancharatnam. Generalized theory of interference and its applications. I. Coherent pensils. Proceedings of the Indian Academy of Sciences, Section A, 44, 247-262(1956).

[54] G X Li, S M Chen, N Pholchai. Continuous control of the nonlinearity phase for harmonic generations. Nature Materials, 14, 607-612(2015).

[55] L Wang, S Kruk, K Koshelev. Nonlinear wavefront control with all-dielectric metasurfaces. Nano Lett, 18, 3978-3984(2018).

[56] W M Ye, F Zeuner, X Li. Spin and wavelength multiplexed nonlinear metasurface holography. Nature Communications, 7, 11930(2016).

[57] E Almeida, O Bitton, Y Prior. Nonlinear metamaterials for holography. Nature Communications, 7, 12533(2016).

[58] Y Gao, Y Fan, Y Wang. Nonlinear holographic all-dielectric metasurfaces. Nano Letters, 18, 8054-8061(2018).

[59] B Reineke, B Sain, R Zhao. Silicon metasurfaces for third harmonic geometric phase manipulation and multiplexed holography. Nano Letters, 19, 6585-6591(2019).

[60] Z Li, W Liu, Z Li. Tripling the capacity of optical vortices by nonlinear metasurface. Laser & Photonics Reviews, 12, 1800164(2018).

[61] W Zang, Z Qin, X Yang. Polarization generation and manipulation based on nonlinear plasmonic metasurfaces. Advanced Optical Materials, 7(2019).

[62] V R Almeida, C A Barrios, R R Panepucci. All-optical control of light on a silicon chip. Nature, 431, 1081-1084(2004).

[63] J S Pelc, K Rivoire, S Vo. Picosecond all-optical switching in hydrogenated amorphous silicon microring resonators. Opt Express, 22, 3797-3810(2014).

[64] M R Shcherbakov, P P Vabishchevich, A S Shorokhov. Ultrafast all-optical switching with magnetic resonances in nonlinear dielectric nanostructures. Nano Lett, 15, 6985-6990(2015).

[65] Fatti N Del, R Bouffanais, F Vallee. Nonequilibrium electron interactions in metal films. Physical Review Letters, 81, 922-925(1998).

[66] C K Sun, F Vallee, L Acioli. Femtosecond investigation of electron thermalization in gold. Physical Review B, 48, 12365-12368(1993).

[67] H Baida, D Mongin, D Christofilos. Ultrafast nonlinear optical response of a single gold nanorod near its surface plasmon resonance. Physical Review Letters, 107, 057402(2011).

[68] G A Wurtz, R Pollard, W Hendren. Designed ultrafast optical nonlinearity in a plasmonic nanorod metamaterial enhanced by nonlocality. Nature Nanotechnology, 6, 106-110(2011).

[69] M X Ren, B H Jia, J Y Ou. Nanostructured plasmonic medium for terahertz bandwidth all-optical switching. Adv Mater, 23, 5540-5544(2011).

[70] M Taghinejad, H Taghinejad, Z Xu. Hot-electron-assisted femtosecond all-optical modulation in plasmonics. Adv Mater, 30, 1704915(2018).

[71] L Caspani, R P Kaipurath, M Clerici. Enhanced nonlinear refractive index in epsilon-near-zero materials. Phys Rev Lett, 116, 233901(2016).

[72] M Z Alam, Leon I De, R W Boyd. Large optical nonlinearity of indium tin oxide in its epsilon-near-zero region. Science, 352, 795-797(2016).

[73] N Kinsey, C DeVault, J Kim. Epsilon-near-zero al-doped zno for ultrafast switching at telecom wavelengths. Optica, 2, 616-622(2015).

[74] M Clerici, N Kinsey, C DeVault. Controlling hybrid nonlinearities in transparent conducting oxides via two-colour excitation. Nature Communications, 8, 15829(2017).

[75] Y M Yang, K Kelley, E Sachet. Femtosecond optical polarization switching using a cadmium oxide-based perfect absorber. Nature Photonics, 11, 390-395(2017).

[76] M Z Alam, S A Schulz, J Upham. Large optical nonlinearity of nanoantennas coupled to an epsilon-near-zero material. Nature Photonics, 12, 79-83(2018).

[77] J Wang, A Coillet, O Demichel. Saturable plasmonic metasurfaces for laser mode locking. Light Sci Appl, 9, 50(2020).

[78] T W Hughes, M Minkov, I A D Williamson. Adjoint method and inverse design for nonlinear nanophotonic devices. ACS Photonics, 5, 4781-4787(2018).

[79] Z Lin, X Liang, M Loncar. Cavity-enhanced second-harmonic generation via nonlinear-overlap optimization. Optica, 3, 233-238(2016).

[80] X Lei, M Rahmani, M Yixuan. Enhanced light-matter interactions in dielectric nanostructures via machine-learning approach. Advanced Photonics, 2, 026003(2020).

[81] G Marino, A S Solntsev, L Xu. Spontaneous photon-pair generation from a dielectric nanoantenna. Optica, 6, 1416(2019).

[82] S Keren-Zur, M Tal, S Fleischer. Generation of spatiotemporally tailored terahertz wavepackets by nonlinear metasurfaces. Nature Communications, 10, 1778(2019).

[83] M Sivis, M Taucer, G Vampa. Tailored semiconductors for high-harmonic optoelectronics. Science, 357, 303-306(2017).