Peacock Feathers Are Stunning. They Can Also Emit Laser Beams

Peacock feathers are Greatly admired for their brilliant iridescent colors, but it turns out that they can also emit laser light when they are tested several times, according to an article published in the journal Scientific Reports. According to the authors, this is the first example of a biolaser cavity in the animal kingdom.

As indicated above, the shiny iridescent colors in things like peacock feathers and butterfly wings come from any pigment molecule but from the way they are structured. Chitine scales (a polysaccharide common to insects) in the butterfly wings, for example, are arranged like roof tiles. Essentially, they form a diffraction network, except that photonic crystals only produce certain colors, or wavelengths, light, while a diffraction network will produce the whole spectrum, a bit like a prism.

In the case of peacock feathers, it is the regular and periodic nanostructures of the bearded – fiber -shaped components composed of melanin stems ordered from keratin – which produce iridescent colors. Different colors correspond to a different spacing of the bearded.

Both are natural examples of what physicists call photonic crystals. Also known as materials of photonic bands, photonic crystals are “adjustable”, which means that they are precisely ordered so as to block certain light wavelengths while leaving the others. Modify the structure by modifying the size of the tiles and the crystals become sensitive to a different wavelength. (In fact, the rainbow charançon can control both the size of its scales and the amount of chitine used to refine these colors if necessary.)

Even better (from the point of view of applications), the perception of color does not depend on the viewing angle. And the scales are not only for aesthetics; They help protect the insect from elements. There are several types of photonic crystals of human origin, but obtaining a better more detailed understanding of how these structures develop in nature could help scientists design new materials with similar qualities, such as iridescent windows, self -cleaning surfaces for cars and buildings, or even waterproof textiles. The paper money could integrate iridescent encrypted models to thwart counterfeiters.

There have been previous examples of random laser emissions in everything, colored cattle bones and blue coral skeletons with insect wings, parrot feathers and human tissues, as well as with salmon iridiphores. The authors of this most recent study were interested in knowing if they could produce similar laser emissions using peacock feathers and, hopefully, identify the specific mechanism.

It was not difficult to obtain peacock feathers, given their popularity for decorative and craft and craft purposes, but the authors only ensured any of the feathers used in their experiments contained impurities (like dyes). They cut any excessive length of beards and mounted the feathers on an absorption substrate. They then infused the feathers with common dyes by pipe the coloring solution directly on them and letting them dry. The feathers have been colored several times in some cases. Then they pumped the samples with light pulses and measured all the resulting emissions.

The team observed laser emissions in two distinct wavelengths for all the color regions of the eyes of the eyes, the regions of green color emitted the most intense laser light. However, they observed no laser emissions from feathers that were only stained once, just in sample feathers that have undergone several drying and complete drying cycles. This is probably due to the best diffusion of the dye and the solvent in the bearded, as well as a possible relaxation of the fibrils in the sheath of keratin.

The authors could not identify the precise microstructures responsible for the laser; It does not seem to be due to the melatonin rods covered with keratin. The co -author Nathan Dawson of Florida Polytechnic University suggested to science that protein granules or small similar structures inside the feathers could operate as a laser cavity. He and his colleague think that one day, their work could lead to the development of biocompatible lasers which could be anchored in complete safety in the human body for detection, imaging and therapy.

This story originally appeared on Ars Technica.