1. Jung, H. et al. Tantala Kerr nonlinear integrated photonics. Optica 8, 811–817 (2021).

    Article  Google Scholar 

  2. 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).

    Article  CAS  Google Scholar 

  3. Wang, C. et al. Ultrahigh-efficiency wavelength conversion in nanophotonic periodically poled lithium niobate waveguides. Optica 5, 1438–1441 (2018).

    Article  CAS  Google Scholar 

  4. Spencer, D. T. et al. An optical-frequency synthesizer using integrated photonics. Nature 557, 81–85 (2018).

    Article  CAS  PubMed  Google Scholar 

  5. Pfeifle, J. et al. Coherent terabit communications with microresonator Kerr frequency combs. Nat. Photon. 8, 375–380 (2014).

    Article  CAS  Google Scholar 

  6. Raval, M., Yaacobi, A. & Watts, M. R. Integrated visible light phased array system for autostereoscopic image projection. Opt. Lett. 43, 3678–3681 (2018).

    Article  PubMed  Google Scholar 

  7. Alexander, K. et al. A manufacturable platform for photonic quantum computing. Nature 641, 876–883 (2025).

    Article  Google Scholar 

  8. 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).

    Article  CAS  Google Scholar 

  9. Pfeiffer, M. H. P. et al. Photonic Damascene process for integrated high-Q microresonator based nonlinear photonics. Optica 3, 20–25 (2016).

    Article  CAS  Google Scholar 

  10. 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).

    Article  PubMed  Google Scholar 

  11. 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).

    Article  CAS  Google Scholar 

  12. Black, J. A. et al. Group-velocity-dispersion engineering of tantala integrated photonics. Opt. Lett. 46, 817 (2021).

    Article  PubMed  Google Scholar 

  13. 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).

    Article  CAS  Google Scholar 

  14. Zhu, D. et al. Integrated photonics on thin-film lithium niobate. Adv. Opt. Photon. 13, 242–352 (2021).

    Article  Google Scholar 

  15. Boes, A. et al. Lithium niobate photonics: unlocking the electromagnetic spectrum. Science 379, eabj4396 (2023).

  16. Wang, C. et al. Lithium tantalate photonic integrated circuits for volume manufacturing. Nature 629, 784–790 (2024).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. 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).

    Article  CAS  Google Scholar 

  18. Wang, C. et al. Integrated lithium niobate electro-optic modulators operating at CMOS-compatible voltages. Nature 562, 101–104 (2018).

    Article  CAS  PubMed  Google Scholar 

  19. Jankowski, M. et al. Ultrabroadband nonlinear optics in nanophotonic periodically poled lithium niobate waveguides. Optica 7, 40–46 (2020).

    Article  CAS  Google Scholar 

  20. 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).

    Article  Google Scholar 

  21. Park, T. et al. High-efficiency second harmonic generation of blue light on thin-film lithium niobate. Opt. Lett. 47, 2706–2709 (2022).

    Article  CAS  PubMed  Google Scholar 

  22. Komljenovic, T. et al. Photonic integrated circuits using heterogeneous integration on silicon. Proc. IEEE 106, 2246–2257 (2018).

    Article  CAS  Google Scholar 

  23. Fathpour, S. Heterogeneous nonlinear integrated photonics. IEEE J. Quantum Electron. 54, 1–16 (2018).

    Article  Google Scholar 

  24. Nader, N. et al. Heterogeneous tantala photonic integrated circuits for sub-micron wavelength applications. Optica 12, 585–593 (2025).

    Article  CAS  Google Scholar 

  25. Beeck, C. O. D. et al. III/V-on-lithium niobate amplifiers and lasers. Optica 8, 1288–1289 (2021).

    Article  Google Scholar 

  26. Snigirev, V. et al. Ultrafast tunable lasers using lithium niobate integrated photonics. Nature 615, 411–417 (2023).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  27. Xiang, C. et al. Laser soliton microcombs heterogeneously integrated on silicon. Science 373, 99–103 (2021).

    Article  CAS  PubMed  Google Scholar 

  28. 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).

    Article  CAS  Google Scholar 

  29. 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).

    Article  CAS  PubMed  Google Scholar 

  30. 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).

    Article  CAS  PubMed  Google Scholar 

  31. Churaev, M. et al. A heterogeneously integrated lithium niobate-on-silicon nitride photonic platform. Nat. Commun. 14, 3499 (2023).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. Nagarajan, R. et al. Large-scale photonic integrated circuits. IEEE J. Sel. Top. Quantum Electron. 11, 50–65 (2005).

    Article  CAS  Google Scholar 

  33. Stojanović, V. et al. Monolithic silicon-photonic platforms in state-of-the-art CMOS SOI processes [Invited]. Opt. Express 26, 13106–13121 (2018).

    Article  PubMed  Google Scholar 

  34. 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).

    Article  CAS  Google Scholar 

  35. Bose, D. et al. Anneal-free ultra-low loss silicon nitride integrated photonics. Light Sci. Appl. 13, 156 (2024).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  36. Carollo, A. R. et al. Amorphous metal oxide mixtures for high-Q integrated nonlinear photonics. Preprint at https://arxiv.org/abs/2508.14887 (2025).

  37. 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).

    Article  Google Scholar 

  38. Yu, S.-P. et al. Spontaneous pulse formation in edgeless photonic crystal resonators. Nat. Photon. 15, 461–467 (2021).

    Article  CAS  Google Scholar 

  39. Zhang, K. et al. Spectral engineering of optical microresonators in anisotropic lithium niobate crystal. Adv. Mater. 36, 2308840 (2024).

    Article  CAS  Google Scholar 

  40. Jones, D. J. et al. Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis. Science 288, 635–639 (2000).

    Article  CAS  PubMed  Google Scholar 

  41. Carlson, D. R. et al. Self-referenced frequency combs using high-efficiency silicon-nitride waveguides. Opt. Lett. 42, 2314–2317 (2017).

    Article  CAS  PubMed  Google Scholar 

  42. 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).

    Article  CAS  Google Scholar 

  43. 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).

    Article  CAS  PubMed  Google Scholar 

  44. 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).

    Article  CAS  PubMed  Google Scholar 

  45. 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).

    Article  CAS  Google Scholar 

  46. Zhou, F. et al. Hybrid-mode-family Kerr optical parametric oscillation for robust coherent light generation on chip. Laser Photon. Rev. 16, 2100582 (2022).

    Article  Google Scholar 

  47. 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).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  48. 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).

    Article  CAS  PubMed  Google Scholar 

  49. Chen, P.-K. et al. Adapted poling to break the nonlinear efficiency limit in nanophotonic lithium niobate waveguides. Nat. Nanotechnol. 19, 44–50 (2024).

    Article  CAS  PubMed  Google Scholar 

  50. 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).

    Article  Google Scholar 

  51. Black, J. A. et al. Optical-parametric oscillation in photonic-crystal ring resonators. Optica 9, 1183 (2022).

    Article  CAS  Google Scholar 

  52. 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).

    Article  CAS  Google Scholar 

  53. Zang, J., Liu, H., Briles, T. C. & Papp, S. B. Foundry manufacturing of octave-spanning microcombs. Opt. Lett. 49, 5143–5146 (2024).

    Article  CAS  PubMed  Google Scholar 

  54. Fazio, M. A. et al. Structure and morphology of low mechanical loss TiO2-doped Ta2O5. Opt. Mater. Express 10, 1687–1703 (2020).

    Article  CAS  Google Scholar 

  55. Malitson, I. H. Interspecimen comparison of the refractive index of fused silica. J. Opt. Soc. Am. 55, 1205–1209 (1965).

    Article  CAS  Google Scholar 

  56. Boyd, R. W. Nonlinear Optics 4th edn (Academic Press, 2020).

  57. Fujii, S. & Tanabe, T. Dispersion engineering and measurement of whispering gallery mode microresonator for Kerr frequency comb generation. Nanophotonics 9, 1087–1104 (2020).

    Article  Google Scholar