Phone Number : 86-15694003007
WhatsApp : +8615694003007
January 25, 2021
An ultra-fast pulsed laser developed by the Korea Institute of Science and Technology (KIST) can produce a frequency 10,000 times higher than current state-of-the-art pulsed lasers, the Physicist Organization reported recently. This was achieved by inserting an additional resonator containing graphene into a fiber-pulsed laser oscillator operating in the femtosecond (10-15 seconds) range. Applying this method to data communications is expected to greatly improve data transmission and processing speeds.
The pulsed laser is repeated for a short period of time, as if it were flashing. It has the advantage of focusing more energy than a CW laser, whose intensity remains constant over time. If a digital signal is loaded into a pulsed laser, each pulse can encode a bit of data. The higher the repetition rate, the more data can be transferred. However, conventional fiber - based pulsed lasers are usually limited in increasing the number of pulses per second above the megahertz level.
Researchers at the KIST Center for Optoelectronic Materials and Devices point out that the time-dependent wavelength and intensity properties of the laser are correlated (Fourier transforms).If a resonator is inserted into a laser oscillator, the wavelength of the pulsed laser can be periodically filtered, thereby modifying the pattern of changes in laser intensity.Based on this study, the researchers synthesized graphene, which has the properties of absorbing and eliminating weak light, and amplifies the intensity simply by sending strong light into the resonator.This enables high rate precise control of laser intensity variation, which increases the pulse repetition rate to a higher level.
Usually graphene is synthesized onto the surface of the catalytic metal, then the product is separated from the catalyst and transferred to the surface of the desired substrate.During the process, there are problems of graphene being damaged or introducing impurities.The researchers solved the problem of reduced efficiency in the manufacturing process by forming graphene directly on the surface of easily accessible copper wires, and further covering the wires with optical fibers as resonators.The results show that the repetition rate of 57.8GHz can be achieved by the new laser, which overcomes the limitation of the repetition rate of the pulsed laser.
In the current situation, the demand for data flow is growing exponentially, and ultra-fast pulsed lasers based on resonators and graphene operating at ultra-high speeds and with allowable tuning properties promise to provide a new method to adapt to rapidly changing data processing requirements, according to the researchers.
(Please note the Chinese edition of this article originates from Jintai News)