[1] A. Fedotova, M. Younesi, J. Sautter, A. Vaskin, F. J. Löchner, M. Steinert, R. Geiss, T. Pertsch, I. Staude, F. Setzpfandt. Second-harmonic generation in resonant nonlinear metasurfaces based on lithium niobate. Nano Lett., 20, 8608-8614(2020).

[2] P. P. Vabishchevich, S. Liu, M. B. Sinclair, G. A. Keeler, G. M. Peake, I. Brener. Enhanced second-harmonic generation using broken symmetry III–V semiconductor Fano metasurfaces. ACS Photon., 5, 1685-1690(2018).

[3] V. F. Gili, L. Carletti, A. Locatelli, D. Rocco, M. Finazzi, L. Ghirardini, I. Favero, C. Gomez, A. Lemaître, M. Celebrano, C. De Angelis. Monolithic AlGaAs second-harmonic nanoantennas. Opt. Express, 24, 15965-15971(2016).

[4] F. J. Löchner, R. Mupparapu, M. Steinert, A. George, Z. Tang, A. Turchanin, T. Pertsch, I. Staude, F. Setzpfandt. Controlling second-harmonic diffraction by nano-patterning MoS₂ monolayers. Opt. Express, 27, 35475-35484(2019).

[5] D. Rocco, A. Zilli, A. Ferraro, A. Borne, V. Vinel, G. Leo, A. Lemaître, C. Zucchetti, M. Celebrano, R. Caputo, C. De Angelis. Tunable second harmonic generation by an all-dielectric diffractive metasurface embedded in liquid crystals. New J. Phys., 24, 045002(2022).

[6] G. Marino, D. Rocco, C. Gigli, G. Beaudoin, K. Pantzas, S. Suffit, P. Filloux, I. Sagnes, G. Leo, C. De Angelis. Harmonic generation with multi-layer dielectric metasurfaces. Nanophotonics, 10, 1837-1843(2021).

[7] R. Sarma, J. Xu, D. de Ceglia, L. Carletti, J. Klem, M. A. Belkin, I. Brener. Control of second-harmonic generation in all-dielectric intersubband metasurfaces by controlling the polarity of χ⁽²⁾. Opt Express, 30, 34533-34544(2022).

[8] L. Carletti, A. Zilli, F. Moia, A. Toma, M. Finazzi, C. De Angelis, D. N. Neshev, M. Celebrano. Steering and encoding the polarization of the second harmonic in the visible with a monolithic LiNbO₃ metasurface. ACS Photon., 8, 731-737(2021).

[9] J. Ma, F. Xie, W. Chen, J. Chen, W. Wu, W. Liu, Y. Chen, W. Cai, M. Ren, J. Xu. Nonlinear lithium niobate metasurfaces for second harmonic generation. Laser Photon. Rev., 15, 2000521(2021).

[10] T. Santiago-Cruz, A. Fedotova, V. Sultanov, M. A. Weissflog, D. Arslan, M. Younesi, T. Pertsch, I. Staude, F. Setzpfandt, M. Chekhova. Photon pairs from resonant metasurfaces. Nano Lett., 21, 4423-4429(2021).

[11] J. Zhang, J. Ma, M. Parry, M. Cai, R. Camacho-Morales, L. Xu, D. N. Neshev, A. A. Sukhorukov. Spatially entangled photon pairs from lithium niobate nonlocal metasurfaces. Sci. Adv., 8, eabq4240(2022).

[12] V. Y. Shur, A. Akhmatkhanov, I. Baturin. Micro-and nano-domain engineering in lithium niobate. Appl. Phys. Rev., 2, 040604(2015).

[13] G. Schreiber, D. Hofmann, W. Grundkoetter, Y. L. Lee, H. Suche, V. Quiring, R. Ricken, W. Sohler. Nonlinear integrated optical frequency converters with periodically poled Ti:LiNbO₃ waveguides. Proc. SPIE, 4277, 144-160(2001).

[14] C. Wang, C. Langrock, A. Marandi, M. Jankowski, M. Zhang, B. Desiatov, M. M. Fejer, M. Lončar. Ultrahigh-efficiency wavelength conversion in nanophotonic periodically poled lithium niobate waveguides. Optica, 5, 1438-1441(2018).

[15] J. Lin, F. Bo, Y. Cheng, J. Xu. Advances in on-chip photonic devices based on lithium niobate on insulator. Photon. Res., 8, 1910-1936(2020).

[16] P. Mutter, K. M. Mølster, A. Zukauskas, V. Pasiskevicius, C. Canalias. Highly-efficient first-order backward second-harmonic generation in periodically poled Rb-doped KTP with a period of 317  nm. Optica Advanced Photonics Congress, NpTu1G.1(2022).

[17] M. Conforti, C. De Angelis, U. K. Sapaev, G. Assanto. Pulse shaping via backward second harmonic generation. Opt. Express, 16, 2115-2121(2008).

[18] M. Lauritano, A. Parini, G. Bellanca, S. Trillo, M. Conforti, A. Locatelli, C. De Angelis. Bistability, limiting, and self-pulsing in backward second-harmonic generation: a time-domain approach. J. Opt. A, 8, S494(2006).

[19] C. Canalias, V. Pasiskevicius. Mirrorless optical parametric oscillator. Nat. Photonics, 1, 459-462(2007).

[20] A. C. Nutt, V. Gopalan, M. C. Gupta. Domain inversion in LiNbO₃ using direct electron-beam writing. Appl. Phys. Lett., 60, 2828-2830(1992).

[21] D. Wei, C. Wang, H. Wang, X. Hu, D. Wei, X. Fang, Y. Zhang, D. Wu, Y. Hu, J. Li, S. Zhu. Experimental demonstration of a three-dimensional lithium niobate nonlinear photonic crystal. Nat. Photonics, 12, 596-600(2018).

[22] G. Rosenman, P. Urenski, A. Agronin, Y. Rosenwaks, M. Molotskii. Submicron ferroelectric domain structures tailored by high-voltage scanning probe microscopy. Appl. Phys. Lett., 82, 103-105(2003).

[23] V. Berger. Nonlinear photonic crystals. Phys. Rev. Lett., 81, 4136-4139(1998).

[24] A. Arie, N. Voloch. Periodic, quasi-periodic, and random quadratic nonlinear photonic crystals. Laser Photon. Rev., 4, 355-373(2010).

[25] N. Broderick, G. Ross, H. Offerhaus, D. Richardson, D. Hanna. Hexagonally poled lithium niobate: a two-dimensional nonlinear photonic crystal. Phys. Rev. Lett., 84, 4345-4348(2000).

[26] J. Zhao, M. Rüsing, M. Roeper, L. M. Eng, S. Mookherjea. Poling thin-film x-cut lithium niobate for quasi-phase matching with sub-micrometer periodicity. J. Appl. Phys., 127, 193104(2020).

[27] J. T. Nagy, R. M. Reano. Submicrometer periodic poling of lithium niobate thin films with bipolar preconditioning pulses. Opt. Mater. Express, 10, 1911-1920(2020).

[28] M. Younesi, R. Geiss, S. Rajaee, F. Setzpfandt, Y.-H. Chen, T. Pertsch. Periodic poling with a micrometer-range period in thin-film lithium niobate on insulator. J. Opt. Soc. Am. B, 38, 685-691(2021).

[29] B. Slautin, H. Zhu, V. Y. Shur. Submicron periodical poling in z-cut lithium niobate thin films. Ferroelectrics, 576, 119-128(2021).

[30] Y. Dong, Q. Dong. Precise control of nanodomain size in LiNbO₃. Mater. Res. Express, 5, 035004(2018).

[31] V. E. Babicheva, A. B. Evlyukhin. Multipole lattice effects in high refractive index metasurfaces. J. Appl. Phys., 129, 040902(2021).

[32] V. Zakomirnyi, A. Ershov, V. Gerasimov, S. Karpov, H. Ågren, I. Rasskazov. Collective lattice resonances in arrays of dielectric nanoparticles: a matter of size. Opt. Lett., 44, 5743-5746(2019).

[33] L. Ciarella, A. Tognazzi, F. Mangini, C. De Angelis, L. Pattelli, F. Frezza. Finite-size and illumination conditions effects in all-dielectric metasurfaces. Electronics, 11, 1017(2022).

[34] Y. Yang, I. I. Kravchenko, D. P. Briggs, J. Valentine. All-dielectric metasurface analogue of electromagnetically induced transparency. Nat. Commun., 5, 5753(2014).

[35] S. Campione, S. Liu, L. I. Basilio, L. K. Warne, W. L. Langston, T. S. Luk, J. R. Wendt, J. L. Reno, G. A. Keeler, I. Brener, M. B. Sinclair. Broken symmetry dielectric resonators for high quality factor Fano metasurfaces. ACS Photon., 3, 2362-2367(2016).

[36] I. Shoji, T. Kondo, A. Kitamoto, M. Shirane, R. Ito. Absolute scale of second-order nonlinear-optical coefficients. J. Opt. Soc. Am. B, 14, 2268-2294(1997).

[37] R. W. Boyd. Nonlinear Optics(2019).

[38] F. Timpu, J. Sendra, C. Renaut, L. Lang, M. Timofeeva, M. T. Buscaglia, V. Buscaglia, R. Grange. Lithium niobate nanocubes as linear and nonlinear ultraviolet Mie resonators. ACS Photon., 6, 545-552(2019).

[39] X. Chen, P. Karpinski, V. Shvedov, K. Koynov, B. Wang, J. Trull, C. Cojocaru, W. Krolikowski, Y. Sheng. Ferroelectric domain engineering by focused infrared femtosecond pulses. Appl. Phys. Lett., 107, 141102(2015).

[40] X. Xu, T. Wang, P. Chen, C. Zhou, J. Ma, D. Wei, H. Wang, B. Niu, X. Fang, D. Wu, S. Zhu, M. Gu, M. Xiao, Y. Zhang. Femtosecond laser writing of lithium niobate ferroelectric nanodomains. Nature, 609, 496-501(2022).

[41] A. Chowdhury, H. M. Ng, M. Bhardwaj, N. G. Weimann. Second-harmonic generation in periodically poled GaN. Appl. Phys. Lett., 83, 1077-1079(2003).

[42] A. Boes, V. Sivan, G. Ren, D. Yudistira, S. Mailis, E. Soergel, A. Mitchell. Precise, reproducible nano-domain engineering in lithium niobate crystals. Appl. Phys. Lett., 107, 022901(2015).

[43] N. V. Bloch, K. Shemer, A. Shapira, R. Shiloh, I. Juwiler, A. Arie. Twisting light by nonlinear photonic crystals. Phys. Rev. Lett., 108, 233902(2012).

[44] D. Wei, C. Wang, X. Xu, H. Wang, Y. Hu, P. Chen, J. Li, Y. Zhu, C. Xin, X. Hu, Y. Zhang. Efficient nonlinear beam shaping in three-dimensional lithium niobate nonlinear photonic crystals. Nat. Commun., 10, 4193(2019).

[45] A. Shapira, R. Shiloh, I. Juwiler, A. Arie. Two-dimensional nonlinear beam shaping. Opt. Lett., 37, 2136-2138(2012).