The research group of Professor Kiichi Hamamoto of the Graduate School of Science and Engineering, Kyushu University has realized the world's first ultra-high-speed "mode selection" light source.It is a new semiconductor laser that can realize high-speed operation of terabit class with one element, which is equivalent to more than 1 times the conventional performance.
The signal transmission speed (wiring speed) in information processing devices such as supercomputers is steadily increasing against the background of AI and big data analysis, and in the near future, it will exceed 1 terabit per second (XNUMX trillion bits). It is expected that the wiring speed of will be required.
It is difficult to achieve a terabit super-class wiring speed with electric signals.Therefore, optical wiring technology using semiconductor laser light is attracting attention.
With conventional semiconductor lasers, the direct modulation speed is only 50 giga / s at the maximum, so it is necessary to integrate multiple semiconductor lasers with different oscillation wavelengths, and the problem is that the scale will be too large to be mounted on small IT equipment. was there.
Under such circumstances, this research group can freely select and oscillate the "spatial mode" (unique light pattern) by utilizing the interference effect of light, even though it is a single semiconductor laser device, and each of them. Realizes a laser light source that can modulate the spatial mode at ultra-high speed.This time, we experimentally demonstrated high-speed frequency response characteristics of over 40 GHz, but in reality it is expected that frequency response characteristics of 100 GHz or more will be obtained for each mode, and 10 or more different spatial modes will be 100 GHz. If it can operate with the above frequency response, a terabit superclass light source will be feasible in the future.
The realization of this optical mode selection light source is expected to contribute to the spread of ultra-high-speed optical wiring technology to small IT equipment and further progress in AI / big data analysis.
The results of this research were held at the International Conference on Fiber Optic Communications (OFC 2018), which will be held at the San Diego Convention Center from March 3 to 11, 15.
