This new technology can use lasers to transmit sound information to specific people!

Before the text begins, "Boko Garden" has to sigh that the rapid development of science and technology is really unexpected. You really don't know what kind of heart technology will pop up next second, such as this one. Let's take a look! Researchers have proved that laser can send sound information to people without any receiving equipment. This ability to send highly directional audio signals through the air can be used to communicate between noisy rooms or to warn individuals of dangerous situations, such as active shooting.

Boko Park-Popular Science: Its new research results were published in Optical Express, a periodical of the Optical Society (OSA). Researchers at the Lincoln Lab of MIT used two different laser methods to transmit different tones, music and recorded speeches at dialogue volume. Charles Wayne, head of the research team, said that our system can be used from a distance and send information directly to people's ears. This is the first system that is completely safe for eyes and skin using laser. It can locate the voice signal of a specific person in any environment. "

This new method is based on the photoacoustic effect, that is, the material absorbs light to form sound waves. In this case, researchers use water vapor in the air to absorb light and produce sound. The researchers said: Even in relatively dry conditions, this method can work, because there is almost always a small amount of water in the air, especially around people. It is found that if the laser wavelength strongly absorbed by water is used, not much water is needed. This is the key, because stronger absorption will produce more sounds. A new sound transmission method is developed from a technology called dynamic photoacoustic spectroscopy (DPAS), which was developed by researchers for chemical detection. In early research, researchers found that scanning or scanning a laser beam at the speed of sound can improve chemical detection.

Ryan M. Sullenberger, the first author of the paper, said: The speed of sound is a very special working speed. In this new paper, it is an effective method to sound by scanning the laser beam with the wavelength absorbed by water at the speed of sound. For dpa-related methods, the researchers changed the length of laser scanning frequency and coded different frequencies or audible pitches in light. A unique feature of this laser scanning technology is that the signal can only be heard at a certain distance from the transmitter. This means that information can be sent to individuals, not everyone who passes through the light beam. It also provides the possibility of sending messages to multiple individuals.

In the laboratory, the researchers showed that commercial equipment can be transmitted to people 2.5 meters away with 60 decibels of sound through laser scanning technology. I believe this system can be easily extended to a longer distance. The traditional photoacoustic method is also tested, which does not need to scan the laser, but encodes the audio information by adjusting the power of the laser beam. There is a trade-off between these two technologies. Traditional photoacoustic methods provide higher fidelity, while laser frequency scanning provides greater sound. Next, the researchers plan to demonstrate these methods in a wider outdoor area. Researchers hope that this technology will eventually become a commercial technology. There are many exciting possibilities for developing communication technology in a beneficial way.

Boko Park-Popular Science | Research/From: American Optical Society

Reference periodical literature: optical express

DOI: 10. 1364

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