[zyk]

No the SteamVR tracking system used by Valve Index, HTC Vive, Pimax and some headsets with extra tracking-plates use IR photo-diodes:

https://triadsemi.com/product/ts4112/

VR users that want full body tracking usually go with outside-in tracking, with tracking devices strapped to their bodies. It is expensive, but the accuracy is very good.

[charcircuit]

SteamVR tracking does use photodiodes, but it is an inside out tracking system. This is because the photodiodes are on the tracked devices. The base stations project distorted planes of light that sweep through the play space and thef planes quickly flash to communicate information like the orientation of the base station.

[zyk]

Thanks for the clarification!