Peacock feathers can emit laser beams
Peacock feathers can emit laser beams
In a study published by Nature, researchers highlight that by applying a special dye they are able to amplify the light
▲ "The most striking aspect is that we're talking about light emission in biological microcavities," noted expert Manuel Fernández Guasti. Photo by Sergio Hernández
Eirinet Gómez
La Jornada Newspaper, Tuesday, August 26, 2025, p. 6
A group of researchers at Florida Polytechnic University discovered that Indian peafowl feathers can emit laser light when a special dye is applied to them. The experiment, published in the journal Nature , paves the way for exploring how to use these biological structures in new detection technologies and medical applications.
The experiment involved soaking peacock feathers in a fluorescent dye called rhodamine 6G. While the feathers were wet, they were illuminated with a laser beam, and they emitted visible light in shades of green and blue. The surprising thing is that the natural shape of the feathers acts as tiny mirrors, reinforcing and amplifying the light.
When asked about this research, Manuel Fernández Guasti, an expert in the design and construction of molecular nitrogen and organic pigment lasers, explained that organic pigment lasers like this one use fluorescent dyes, similar to those that glow under black light at parties.
He emphasized that one of their characteristics is that they are tunable, meaning, like a radio, the frequency can be adjusted to obtain different colors of laser light with great precision. He added that the rhodamine 6G used in this study is one of the most widely used pigments in optics because it emits light with great intensity, in shades of red.
The most interesting aspect here, Fernández Guasti mentioned, is that instead of dissolving rhodamine 6G inside a quartz cell as is usual, it was applied directly to the feathers, and it is from within these structures that the laser emission is observed. "The most striking aspect is that we are talking about light emission in biological microcavities," he noted.
Regarding the possibility that an organic material, such as that of this bird, could be used to amplify and emit laser light, the scientist stated that a few years ago it was thought to be unusual, but as experiments have progressed, it has been noted that it is more common than previously thought.
“Now we say: these beetles, these types of flies, some toucans, or these peacocks, could also have natural structures that reflect light in similar ways.”
From his perspective, one of the most obvious limitations of the peacock feather experiment is that it must be wet to emit the laser. "This is a significant problem because in many other examples, the emission has been observed in dry materials."
Fernández Guasti, who founded the Quantum Optics Laboratory at the Iztapalapa branch of the Autonomous Metropolitan University, mentioned that if he wanted to reproduce the study and improve it, he wouldn't work with rhodamine 6G, but with another dye called coumarin.
“The iridescence of peacock feathers is green, not red, like rhodamine 6G. So, I would go for a substance, like coumarin, that emits light in the same shades as the feathers.”
Exploration with organic materials
Beyond scientific curiosity, Guasti believes the main contribution of this type of research is that it expands the study of natural structures with the potential to create optical sensors—capable of detecting changes in the environment such as humidity, temperature, or pollutants—or biotechnology tools that aid in medical treatments.
"These explorations we're doing with different organic materials are generating new ideas. Where are they going? We don't know, but there are important advances, especially in the field of health."
Fernández Guasti, who a few years ago conducted an experiment on the wings of a Mexican passionflower butterfly, which he illuminated with two lasers (red and green) to observe diffraction patterns—the drawings that form when light bends and disperses upon impact with the wing structures—highlighted the importance of exploring such interdisciplinary areas as optics and biology.
In a message to young researchers, he said: "While speaking different languages and having different styles of doing things makes meeting people difficult at first, it later becomes an enriching experience."
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