Jung, H. et al. Tantala Kerr nonlinear integrated photonics. Optica 8, 811–817 (2021).
Desiatov, B., Shams-Ansari, A., Zhang, M., Wang, C. & Lončar, M. Ultra-low-loss integrated visible photonics using thin-film lithium niobate. Optica 6, 380–384 (2019).
Wang, C. et al. Ultrahigh-efficiency wavelength conversion in nanophotonic periodically poled lithium niobate waveguides. Optica 5, 1438–1441 (2018).
Spencer, D. T. et al. An optical-frequency synthesizer using integrated photonics. Nature 557, 81–85 (2018).
Pfeifle, J. et al. Coherent terabit communications with microresonator Kerr frequency combs. Nat. Photon. 8, 375–380 (2014).
Raval, M., Yaacobi, A. & Watts, M. R. Integrated visible light phased array system for autostereoscopic image projection. Opt. Lett. 43, 3678–3681 (2018).
Alexander, K. et al. A manufacturable platform for photonic quantum computing. Nature 641, 876–883 (2025).
Moss, D. J., Morandotti, R., Gaeta, A. L. & Lipson, M. New CMOS-compatible platforms based on silicon nitride and Hydex for nonlinear optics. Nat. Photon. 7, 597–607 (2013).
Pfeiffer, M. H. P. et al. Photonic Damascene process for integrated high-Q microresonator based nonlinear photonics. Optica 3, 20–25 (2016).
Luke, K., Dutt, A., Poitras, C. B. & Lipson, M. Overcoming Si3N4 film stress limitations for high quality factor ring resonators. Opt. Express 21, 22829–22833 (2013).
Belt, M., Davenport, M. L., Bowers, J. E. & Blumenthal, D. J. Ultra-low-loss Ta2O5-core/SiO2-clad planar waveguides on Si substrates. Optica 4, 532–536 (2017).
Black, J. A. et al. Group-velocity-dispersion engineering of tantala integrated photonics. Opt. Lett. 46, 817 (2021).
Jung, H. & Tang, H. X. Aluminum nitride as nonlinear optical material for on-chip frequency comb generation and frequency conversion. Nanophotonics 5, 263–271 (2016).
Zhu, D. et al. Integrated photonics on thin-film lithium niobate. Adv. Opt. Photon. 13, 242–352 (2021).
Boes, A. et al. Lithium niobate photonics: unlocking the electromagnetic spectrum. Science 379, eabj4396 (2023).
Wang, C. et al. Lithium tantalate photonic integrated circuits for volume manufacturing. Nature 629, 784–790 (2024).
Karvounis, A., Timpu, F., Vogler-Neuling, V. V., Savo, R. & Grange, R. Barium titanate nanostructures and thin films for photonics. Adv. Opt. Mater. 8, 2001249 (2020).
Wang, C. et al. Integrated lithium niobate electro-optic modulators operating at CMOS-compatible voltages. Nature 562, 101–104 (2018).
Jankowski, M. et al. Ultrabroadband nonlinear optics in nanophotonic periodically poled lithium niobate waveguides. Optica 7, 40–46 (2020).
Younesi, M. et al. Periodic poling with a micrometer-range period in thin-film lithium niobate on insulator. J. Opt. Soc. Am. B 38, 685–691 (2021).
Park, T. et al. High-efficiency second harmonic generation of blue light on thin-film lithium niobate. Opt. Lett. 47, 2706–2709 (2022).
Komljenovic, T. et al. Photonic integrated circuits using heterogeneous integration on silicon. Proc. IEEE 106, 2246–2257 (2018).
Fathpour, S. Heterogeneous nonlinear integrated photonics. IEEE J. Quantum Electron. 54, 1–16 (2018).
Nader, N. et al. Heterogeneous tantala photonic integrated circuits for sub-micron wavelength applications. Optica 12, 585–593 (2025).
Beeck, C. O. D. et al. III/V-on-lithium niobate amplifiers and lasers. Optica 8, 1288–1289 (2021).
Snigirev, V. et al. Ultrafast tunable lasers using lithium niobate integrated photonics. Nature 615, 411–417 (2023).
Xiang, C. et al. Laser soliton microcombs heterogeneously integrated on silicon. Science 373, 99–103 (2021).
Vanackere, T. et al. Heterogeneous integration of a high-speed lithium niobate modulator on silicon nitride using micro-transfer printing. APL Photon. 8, 086102 (2023).
Chang, L. et al. Heterogeneous integration of lithium niobate and silicon nitride waveguides for wafer-scale photonic integrated circuits on silicon. Opt. Lett. 42, 803–806 (2017).
Ghosh, S. et al. Wafer-scale heterogeneous integration of thin film lithium niobate on silicon-nitride photonic integrated circuits with low loss bonding interfaces. Opt. Express 31, 12005–12015 (2023).
Churaev, M. et al. A heterogeneously integrated lithium niobate-on-silicon nitride photonic platform. Nat. Commun. 14, 3499 (2023).
Nagarajan, R. et al. Large-scale photonic integrated circuits. IEEE J. Sel. Top. Quantum Electron. 11, 50–65 (2005).
Stojanović, V. et al. Monolithic silicon-photonic platforms in state-of-the-art CMOS SOI processes [Invited]. Opt. Express 26, 13106–13121 (2018).
Sacher, W. D., Huang, Y., Lo, G.-Q. & Poon, J. K. S. Multilayer silicon nitride-on-silicon integrated photonic platforms and devices. J. Lightwave Technol. 33, 901–910 (2015).
Bose, D. et al. Anneal-free ultra-low loss silicon nitride integrated photonics. Light Sci. Appl. 13, 156 (2024).
Carollo, A. R. et al. Amorphous metal oxide mixtures for high-Q integrated nonlinear photonics. Preprint at https://arxiv.org/abs/2508.14887 (2025).
Lu, X., Rogers, S., Jiang, W. C. & Lin, Q. Selective engineering of cavity resonance for frequency matching in optical parametric processes. Appl. Phys. Lett. 105, 151104 (2014).
Yu, S.-P. et al. Spontaneous pulse formation in edgeless photonic crystal resonators. Nat. Photon. 15, 461–467 (2021).
Zhang, K. et al. Spectral engineering of optical microresonators in anisotropic lithium niobate crystal. Adv. Mater. 36, 2308840 (2024).
Jones, D. J. et al. Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis. Science 288, 635–639 (2000).
Carlson, D. R. et al. Self-referenced frequency combs using high-efficiency silicon-nitride waveguides. Opt. Lett. 42, 2314–2317 (2017).
Gayer, O., Sacks, Z., Galun, E. & Arie, A. Temperature and wavelength dependent refractive index equations for MgO-doped congruent and stoichiometric LiNbO3. Appl. Phys. B 91, 343–348 (2008).
Tai, C.-Y. et al. Determination of nonlinear refractive index in a Ta2O5 rib waveguide using self-phase modulation. Opt. Express 12, 5110–5116 (2004).
Ikeda, K., Saperstein, R. E., Alic, N. & Fainman, Y. Thermal and Kerr nonlinear properties of plasma deposited silicon nitride/silicon dioxide waveguides. Opt. Express 16, 12987–12994 (2008).
Yi, X., Yang, Q.-F., Yang, K. Y., Suh, M.-G. & Vahala, K. Soliton frequency comb at microwave rates in a high-Q silica microresonator. Optica 2, 1078 (2015).
Zhou, F. et al. Hybrid-mode-family Kerr optical parametric oscillation for robust coherent light generation on chip. Laser Photon. Rev. 16, 2100582 (2022).
Yu, S.-P., Lucas, E., Zang, J. & Papp, S. B. A continuum of bright and dark-pulse states in a photonic crystal resonator. Nat. Commun. 13, 3134 (2022).
Rao, A. et al. Actively-monitored periodic-poling in thin-film lithium niobate photonic waveguides with ultrahigh nonlinear conversion efficiency of 4600 %W−1cm−2. Opt. Express 27, 25920–25930 (2019).
Chen, P.-K. et al. Adapted poling to break the nonlinear efficiency limit in nanophotonic lithium niobate waveguides. Nat. Nanotechnol. 19, 44–50 (2024).
Xin, C. J. et al. Wavelength-accurate and wafer-scale process for nonlinear frequency mixers in thin-film lithium niobate. Commun. Phys. 8, 136 (2025).
Black, J. A. et al. Optical-parametric oscillation in photonic-crystal ring resonators. Optica 9, 1183 (2022).
Brodnik, G. M., Liu, H., Carlson, D. R., Black, J. A. & Papp, S. B. Nanopatterned parametric oscillators for laser conversion beyond an octave. Optica 12, 337–342 (2025).
Zang, J., Liu, H., Briles, T. C. & Papp, S. B. Foundry manufacturing of octave-spanning microcombs. Opt. Lett. 49, 5143–5146 (2024).
Fazio, M. A. et al. Structure and morphology of low mechanical loss TiO2-doped Ta2O5. Opt. Mater. Express 10, 1687–1703 (2020).
Malitson, I. H. Interspecimen comparison of the refractive index of fused silica. J. Opt. Soc. Am. 55, 1205–1209 (1965).
Boyd, R. W. Nonlinear Optics 4th edn (Academic Press, 2020).
Fujii, S. & Tanabe, T. Dispersion engineering and measurement of whispering gallery mode microresonator for Kerr frequency comb generation. Nanophotonics 9, 1087–1104 (2020).
