Researchers have successfully demonstrated a laser that can transmit audio to a person via the air without wearing any type of special equipment.
The technique is based on photoacoustic effect using the water vapor to absorb light and create sound. According to the researchers, it can transmit various tones, music, and recorded speech at a conversational volume to a person at the other end of the room without anyone else hearing.
The details of the research were published in the journal Optics Letters by a team of researchers from MIT's Lincoln Lab, a research facility of the U.S. Department of Defense.
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