Extended Data Fig. 1: 3D layer transition design of Si-SiN and SiN-SiN with large vertical separation.
From: 3D integration enables ultralow-noise isolator-free lasers in silicon photonics
a. We compare the minimum transition length for a SiN-to-SiN transition and a Si-to-SiN transition over a vertical distance spanning 2 μm to 5 μm. The SiN-to-SiN transition transfers power more efficiently for vertical separations exceeding 2 μm, enabling a correspondingly shorter transition length. b. Example of the symmetric supermode of a Si-to-SiN vertical transition. c. Example of symmetric supermode in a SiN-to-SiN vertical transition.
