Correction: Cheng et al. Grating Couplers on Silicon Photonics: Design Principles, Emerging Trends and Practical Issues. Micromachines 2020, 11, 666

In the original publication [1], there was a mistake in Equation (8) as published. Given the angle definition in the publication, “$\cos \theta$” in Equation (8) should be “$\sin \theta$”. The corrected Equation (8) is shown below.

$$m\lambda =n_{eff}\sqrt{x^2+y^2}-x{n}_0\sin \theta$$

(8)

The authors apologize for any inconvenience caused and state that the scientific conclusions are unaffected. This correction was approved by the Academic Editor. The original publication has also been updated.