I don't think the Lidar in apple's stuff is actually a lidar, I think its a structured light sensor.[1]
What do I mean by that? lidar sends pulses of light and works out the difference between emission time and arrival time to work out how far the pulse has travelled.
The structured light sensor emits a pattern or dots, and any distortion of that can be used to compute the shape of an object.
[1] https://image-ppubs.uspto.gov/dirsearch-public/print/downloa...
They aren't talking about FaceID.
iPhone 12 introduced a lidar sensor in the back.
if you actually read the paper you linked, you can clearly see the structured light pattern emitted by the laser. (https://media.springernature.com/lw685/springer-static/image... or figure two.)
Also the patent I linked was filed in 2020, after faceID was rolled out.
