A research group from Duke University has created some truly stunning leaps forward in the world of optical physics. In fact, they had already managed to create static optical knots with laser beams. This new cultural approach increases the flow of information. It provides the ability to manipulate microscopic particles in three dimensions. The discoveries, detailed in full last week, promise to have deep impact across the life sciences, material sciences and nanotechnology.
In the past, people have thought of knots as objects formed with pliable substances. Bends and folds in these textiles create striking in-formed figures. The Duke team has gone above and beyond in deepening their understanding. Yet Fernandez and his colleagues have shown that lasers can produce complex optical knots that can be used to encode information. The entire experiment transpired across an area the size of a dining room table. In comparison, their teammates in South Africa built an elaborate setup encompassing two different buildings.
Creating Optical Knots
To demonstrate their technique, the researchers powered a laser beam and used a holographic strip to separate this single beam into five custom beams. They used this approach to produce the optical knot, which was later deployed for transmitting information encoded in a knot in the wavefront. Mirrors were strategically placed to simulate the laser beam traveling nearly 1,000 feet, mimicking conditions that could be encountered in real-world applications.
One of the principal researchers on the project, Natalia Litchinitser, explained why more research on these optical knots is necessary. “Before we can actually use optical knots for any kind of application, we have to really study them and understand how they behave,” she stated.
The team discovered that as turbulence gets worse, optical knots increasingly fall apart. They tend to simplify down to rather basic topologies, such as two joined circles or one circle. “As it turns out, they’re not guaranteed to be stable, but we can make them more stable,” Litchinitser added. This result reinforces the idea that even if optical knots can be artificially produced, their persistence depends on environmental factors.
Implications for Information Transmission
The resulting ability to produce arbitrary stable optical knots will allow new types of robust information transmission. The researchers hope that these knots can be used to transmit complicated information through chaotic environments while maintaining structural integrity. The implications for telecommunications and data transfer would be immense, allowing us to create more effective, reliable, and speedy communication networks.
The idea of optical knots was first proposed almost twenty years ago. It remained mostly theoretical until breakthroughs in technology allowed for real-world experimentation. From experience, Litchinitser said past understanding of the stability of these forms was a bit sunshiny. “People thought that because these shapes are mathematically stable objects, they should be able to be transmitted through complex environments without any complications,” she explained.
Measuring Turbulence with Optical Knots
Beyond information transmission, the use of optical knots has potential for improving measurements of turbulence in turbulent pockets of air. The researchers’ next step will be to investigate how these persistent light structures can be adapted as new tools for detecting atmospheric phenomena. This would have wide ranging effects in everything from meteorology to aviation safety.
This partnership between Duke University and South African researchers provides a perfect example of combining complementary resources and expertise. The latter’s large-scale experiment offered important insights that filled in the picture and complemented Duke’s much smaller, more focused approach. Getting a handle on how to make and govern optical knots would open new pathways in everything from quantum optics to complex systems research.