The shadow of the laser beam appears as a horizontal line against a blue background.
Abrahao et al. (2024)
Usually light casts shadows on other objects, but with the help of rubies, laser beams themselves can cast shadows.
When two laser beams interact, they don’t collide like the lightsabers in the movies. star warssay Rafael Abrahao At Brookhaven National Laboratory in New York. In real life, they simply pass through each other. But Abrahao and his colleagues discovered a way for one laser beam to block another, causing its shadow to appear.
The key ingredient was ruby cubes. The researchers illuminated the cube with a green laser beam while shining a blue laser from the side. When green light passed through the ruby’s atoms, its properties changed in a unique way, which affected its response to blue light.
Atoms affected by the green light blocked the blue laser light instead of letting it pass, creating a shadow that was exactly the same shape as the green laser beam. Remarkably, the researchers were able to project blue light onto a screen and see this “laser shadow” with the naked eye.
Abrahao says he and his colleagues had a long discussion about whether what they had created was actually worthy of a shadow. Because moving the green laser beam also moved the green laser beam, we were able to see it without special equipment, and we were able to project it onto commonplace objects like markers, so we finally found a positive answer. I made a judgment.
Historically, understanding shadows has been critical to understanding what light can do and how it can be used, and this experiment has added to scientists’ light manipulation toolbox. Add unexpected technology, he says.
thomas kloba Researchers at the University of Erlangen-Nuremberg in Germany say their experiment used a known process to create an impressive visual demonstration of how materials can help control light. . For example, the interaction between lasers and rubies is similar to the interaction of materials used in laser eye surgery, and if the laser light becomes dangerously strong, it must be able to react by blocking the laser light. yeah.
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Source: www.newscientist.com
