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Microsoft Researchers Use Light Beams To Charge Smartphones

Posted by samzenpus on from the power-up dept.

angry tapir writes A group of Microsoft researchers has built a prototype charger for smartphones that can scan a room until it locates a mobile device compatible with the system and then charge the handset using a light beam. The researchers say they can achieve efficiency comparable to conventional wired phone chargers. The biggest barrier? Smartphones don't (yet) come with solar panels attached.

1 of 65 comments (clear)

  1. Re:Unanswered questions by Anonymous Coward · · Score: 1, Informative

    > Q: 1. Would infrared work just as well?
    >> A: 1. Higher wavelengths have higher energy. So IR would be worse than visible light.

    No. In order to achieve optimum efficiency, you need to choose a wavelength with an energy per photon just slightly above the bandgap for the photodiode. If you use a silicon photodiode, IR-light of app. 950nm would work best.