Publisher Correction: Hertz-linewidth semiconductor lasers using CMOS-ready ultra-high-Q microresonators

Correction to: Nature Photonics https://doi.org/10.1038/s41566-021-00761-7, published online 11 February 2021.

In the version of this Article originally published, the configuration of the external-cavity 4,000-Hz linewidth laser was given incorrectly in Table 1 as ‘Hybrid III–V/Si₃N₄’; it should have been ‘Heterogeneous III–V/Si₃N₄’. This has now been corrected in all versions of the Article.