With Windows Hello Microsoft has gone all-in on biometrics, but until very recently Windows 10 Mobile did not support fingerprint readers natively.
This does not mean Microsoft has not been thinking of the technology, and in a recently published patent they describe a fingerprint reader which can be an integral part of the screen of the device, taking up much less space and allowing for thinner smartphones.
The technology would use a wave guide underneath the glass plus a filter which would allow a sensor on the side of the glass to sense the ridges of a fingerprint placed on the glass some distance away. The light from the wave guide may even be transmitted slightly further away via a fibre-optic cable, allowing more flexibility in the design of the handset. Microsoft notes the technology can be used both with LED and AMOLED screens.
Of course at present Microsoft is out of the smartphone manufacturing game, but if the mythical Surface Phone ever arrives we hope it features something as cool as this.
See the patent here.