Recently, a foreign research team announced the creation of a special laser system, which is based on a spider web like network and can produce different light colors through precise control.
The system was jointly invented by a team led by researchers from Imperial College London and partners from Italy and Switzerland, and can be used for new sensing and computing applications. In addition, the team has cooperated with European research and industrial partners to explore the application of the system in machine learning.
In traditional lasers, light is reflected between two mirrors in a material (active medium), which amplifies the light until it reaches a certain threshold. The laser beam is very narrow and stable over a long distance. However, these lights usually produce only one frequency, corresponding to one color.
However, the working principle behind the above network laser is different. It is a mesh structure composed of nano optical fibers that is fused together to form a mesh network. Light travels along the fiber and interferes with each other in this way, producing hundreds of colors at the same time.
In this system, the color of light will eventually be mixed in a complex way and emitted randomly in all directions. To precisely control this network laser, so that it can only emit one color or a combination of multiple colors at a time, it is actually achieved by forming a unique "lighting mode" on the network laser. After that, each precise mode will produce different laser colors, or combinations of different colors.
This "lighting mode" was created using Digital Micro Mirror Device (DMD), a computer-controlled device with thousands of mirrors. The Digital Micro Mirror Device (DMD) is optimized by an algorithm that selects the best mode for a specific laser color.
The team said that the new network laser system can have many applications, especially can be integrated into the chip. For example, they can be used as highly secure hardware keys, where the illumination mode becomes a secure key that generates a password in the form of a laser spectrum. In addition, because the laser is highly sensitive to the correct lighting mode, this network laser can also be used as a sensor to track small changes in the surrounding surface.
This system is the result of five years of cooperation between the Department of Physics and the Department of Mathematics of Imperial College of Technology. The research team is led by Dhruv Saxena and Alexis Arnaudon, postdoctoral researchers in the Department of Physics and the Department of Mathematics respectively. The research team developed a tool to optimize the lighting mode based on physical modeling and theory, and demonstrated it in the actual scene. At present, the research results have been published in the journal Nature Communications.
Professor Riccardo Sapienza, co-author of the Physics Department of Imperial College of Technology, said: "We combine the mathematics of network theory with laser science to tame these complex lasers. We believe that this will be the core of optical processing on chips, and we are now testing it as machine learning hardware."
Professor Mauricio Barahona, coauthor of the Mathematics Department of Imperial College, pointed out: "This is an example of combining mathematics and physics. It shows how the properties of the network affect and help control the laser process. The next great challenge is to design networks and illumination models to control the time profile of the laser and encode information in it."
The research is part of the EU Horizon 2020 project CORAL (Network Random Laser on Control Chip). The above research team, together with IBM Zurich, will promote the commercialization of the emerging field of network lasers. It is reported that this research was also funded by the Engineering and Natural Science Research Council (EPSRC) of the United Kingdom.
Source: Sohu
