Riemensberger, J. et al. A photonic integrated continuous-travelling-wave parametric amplifier. Nature 612, 56–61 (2022). Article ADS CAS PubMed Google Scholar Tran, M. et al. Extending the spectrum of fully integrated photonics. Nature 610, 54–60 (2022). Article ADS CAS PubMed PubMed Central Google Scholar Kaur, P. et al. Hybrid and heterogeneous photonic integration. APL Photonics 6,
