Researchers at the Harvard School of Engineering and Applied Sciences. John A. Paulson (Harvard John A. Paulson School of Engineering and Applied Sciences - SEAS) was the first in the world to use a semiconductor laser to create a communication channel. The hybrid electron-photonic device uses a laser to generate and transmit microwave signals and could one day lead to a new type of high-frequency wireless communication.
Listening to Dean Martin perform his famous composition "Volare" from a computer speaker may seem like a completely ordinary thing, but when you know that this is the first radio broadcast using laser technology, you experience a completely different emotion. The new device, developed by the SEAS team, uses an infrared laser split into beams of different frequencies. If an ordinary laser generates a beam at one frequency, like a violin playing an exact note, then the device created by scientists emits many beams with different frequencies, which are evenly distributed in the stream, like the teeth of a hairbrush, which gave the original name of the device - infrared laser-frequency comb (infrared laser frequency comb).
In 2018, the SEAS team discovered that the "teeth" of a laser comb can resonate with each other, causing the electrons in the laser cavity to oscillate in the form of microwave frequencies in the radio range. The top electrode of the device has an etched slot that acts as a dipole antenna and acts as a transmitter. By changing the parameters of the laser (modulating it), the team was able to encode digital data in microwave radiation. The signal was then transmitted to the receiving point, where it was picked up by a horn antenna, filtered and decoded by a computer.
"This integrated all-in-one device holds great promise for wireless communications," says Marco Piccardo, SEAS researcher. "While the dream of terahertz wireless communications is far from being realized, this research provides us with a clear roadmap showing where we need to go."
In theory, such a laser transmitter can be used to transmit a signal at a frequency of 10β100 GHz and up to 1 THz, which in the future will make it possible to transmit data at speeds up to 100 Gbit/s.
Research in the scientific journal PNAS.
Source: 3dnews.ru