Laser is a kind of revolutionary equipment, but a technical challenge hinders their development. The light they emit will be reflected back to the laser itself, making the laser unstable or even ineffective. In the real world, this challenge can be solved by using large equipment with magnetic barrier properties. However, on the scale of chips, engineers hope that lasers can one day change computer circuits, but facts have proved that effective chip level isolators are difficult to achieve.
Against this background, American researchers said that they have created a simple and effective chip level isolator that can be placed in a semiconductor material hundreds of times thinner than a piece of paper. "Chip level isolation is one of the great challenges facing photonics." A professor of electrical engineering at an American university said that she was the senior author of the research published in the journal Nature Photonics on December 1.
"Each laser needs an isolator to prevent the back reflected laser from entering the laser and damaging the stability of the laser." He added that the device has a great impact on daily computing and will certainly affect the next generation of technologies, such as quantum computing. "Nanoscale isolators are promising for several reasons. First of all, they are passive. They do not require external input, complex electronic equipment or magnetic technology challenges, which hinder the development of chip level lasers. These additional mechanisms generate bulky equipment, and may lead to electrical interference, which may damage other components on the chip. Another advantage is that the new isolators are also made up of common isolators The well-known semiconductor based materials can be made using the existing semiconductor processing technology, which may simplify the path of large-scale production. "
In fact, the new isolator is shaped like a ring. It is made of silicon nitride, a material based on the most commonly used semiconductor silicon. The powerful main laser beam enters the ring, and the photons begin to rotate clockwise around the ring. At the same time, a reflected beam will return to the ring in the opposite direction and rotate counterclockwise.
Another co author said: "The laser energy we injected has cycled many times, which enables us to accumulate energy in the ring. This increasing energy changes the weaker beam, while the stronger beam continues to be unaffected. And only the reflected light is effectively offset. Then, the main laser leaves the ring and is isolated along the desired direction."
Scientists have built a prototype as proof of concept and can connect two annular isolators in series to achieve better performance. "The next step includes researching isolators with different frequencies of light, and integrating components more closely on the chip scale to explore other uses of isolators and improve performance." Scientists explained.
Source: Science and the Universe
