Hello. Interesting question.

I just had a quick look at https://thenextweb.com/plugged/2020/10/14/wait-whats-a-lidar-sensor-and-whys-it-on-the-iphone-12-pro/

It seems to say that this is not an infra-red based sensor, but a Lidar one. Clearly it would have to be low power and a quite diffuse beam or it would be hazardous to people's eyes, not to mention a huge drain on the battery. If there's only 1 transmitter and 1 receiver, then, yes it's definitely an active ranging system (time of flight sensor) like a regular Lidar. I am just guessing, but I suppose they use a MEMS IMU to provide the pose (position and attitude) of the phone while it is building a depth map.

Please recommend if you find this answer useful.

Thanks for your answer Graham W Pulford. The MEMS solution is indeed possible, but I am not very familiar with how it works. In the link you provided, there is a Twitter video showing the iPad scanning under infrared and we can see dot patterns which is quite interesting because then it may well be a ToF camera too..?

I think the lidar sensor used in 2020's iPad and iPhone's is a ToF camera.

Hi all, I thought that some of you might be interested: I found a US Patent (no. 10,324,171 B2) filed by Apple in 2019 in which is explained that the technology (if it is the one applied in the iPad/iPhone) does use a type of solid-state lidar as Graham W Pulford predicted. However, instead of the MEMS, the patent describes the approach as SPAD-based.

Hi, my guess is structured light.

Structured light does not necessarily use high-energy waves such as a laser. Note that the visibility range for humans is very narrow. Any lighting frequencies that are out of humans' visibility range and are safe can be possible.

Hi Arnadi Murtiyoso

An interesting paper recently published in the ISPRS Archive Article THE IPAD PRO BUILT-IN LIDAR SENSOR: 3D RAPID MAPPING TESTS A...