At present, optical waveguides for optical circuits have been able to achieve higher bandwidth and generate less heat than thin copper wires for electronic chips. On the other hand, the size of optical integrated circuits is rapidly reaching the nanometer level, which requires the scientific community to find new methods that can effectively drive and control nano light sources.
In order to meet this demand, researchers at Korea University have developed an all optical method to drive multiple high-density nano laser arrays, which can realize chip based optical communication links. Its data processing and transmission speed is faster than current electronic devices.
Replace electrode with light
In this research published in the journal Optica, the use of optical fiber eliminates the need for large and complex electrodes commonly used to drive laser arrays. In the experimental operation, the densely integrated nano laser array (in which the distance between lasers is only 18 microns) can be driven and programmed by the light from a single fiber.
Myung Ki Kim, head of the research team of Koryo University, said: "The optical equipment integrated on the chip is becoming one of the potential substitutes for electronic integrated equipment. At present, electronic integrated equipment has to strive to keep up with the latest data processing requirements. By eliminating the large and complex electrodes usually used to drive the laser array, we have reduced the overall size of the laser array, and also eliminated the heat output and processing delay caused by the electrode driver."
Myung Ki Kim said that the development of optical interconnection technology equipped with high-density nano lasers will improve the information processing efficiency of the data center. This can not only realize streaming media of ultra high-definition movies and larger scale online interaction and games, but also accelerate the expansion of the Internet of Things and provide fast connections for big data analysis.
In order to output light smoothly, the laser needs to obtain energy supply during the pumping process. For nano laser arrays, this is usually done by using a pair of electrodes for each laser in the array, which requires a large amount of chip space and energy consumption, and also leads to processing delays. The researchers replaced these electrodes with a unique optical drive that can produce programmable light patterns through interference. This pump light can be transmitted along the fiber to the printed nano laser.
Korean researchers used high-resolution transfer printing technology to manufacture multiple photonic crystal nano lasers with an interval of 18 microns. These arrays are applied to the optical fiber surface with a diameter of 2 microns, which must be completed in a way to accurately align the nano laser array with the interference pattern. The interference pattern can also be corrected by adjusting the polarization and pulse width of the driving beam.
Single fiber laser drive
Experiments show that the design can drive multiple nano laser arrays through the output light of a single fiber. In addition, the results are in good agreement with the numerical results, which indicates that the printed nano laser array can be completely controlled by the pump light interference pattern.
The research team said that all-optical laser driving and programming technology can also be applied to chip based silicon photonic systems, which may play a key role in the development of chip to chip or on-chip optical interconnection. Next, they still need to demonstrate how the modes of silicon waveguides are independently controlled. If this can be achieved, it is expected to bring about a great leap in the development of optical interconnection and optical integrated circuits.
Source: OFweek Laser Network
