Peacock plumages are much admired for their bright iridescent colors, but it turns out that they can also emit a laser -light when dyed many times, according to Paper Published in the magazine Scientific Reports. According to the authors, it is the First example from a biolase cavity within the animal kingdom.
As previously reportedThe brilliant iridescent colors in things like peacocks and butterfly wings do not come from some pigment molecules but from how they are structured. The scales of Chitino (polysaccharide common to insects) in butterfly wings, for example, are arranged as roofs. Basically they form a a diffraction gridIn addition to photon crystals only produce certain colors, or wavelengths, of light, while diffraction grid will produce the entire spectrum, as well as prism.
In the case of Peacock plumes, it is the regular, periodic nanostructures of the beards-Fiber-like components composed of ordered melanin sticks coated in keratin-which produce the iridescent colors. Different colors correspond to different gaps of the beards.
Both occur naturally examples of what physicists call photon crystals. Also known as photon band materials, photon crystals are “customizable”, which means they are precisely ordered so that they block some wavelengths of light while leaving others. Change the structure by changing the size of the tiles, and the crystals become sensitive to a different wavelength. (In fact, the Rainbow Weevil can control Both the size of its scales and how much kitin is used to set those colors as needed.)
Even better (from an application point of view), the perception of color does not depend on the visual angle. And the scales are not just for aesthetics; They help shield the insect of the elements. There are several types of handmade photon crystalsBut gaining a better and more detailed understanding of how these structures grow in nature could help scientists draw new materials with similar qualities, such as iridescent windows, self-cleaning surfaces for cars and buildings, or even waterproof textiles. Paper currency could incorporate encrypted iridescent patterns to fake counterfeiters.
Were previous examples of random laser emissions in all, of stained Beef bones And blue coral skeletons to insect wings,, Parrot feathersand human tissueas well as Salmon Iridipores. The authors of this most recent study were interested in whether they could produce similar laser emissions with peacocks and hopefully identify the specific mechanism.
It was not difficult to get the Peacock plucks, considering how popular they are for decorative and arts and crafts, but the authors made sure that none of the feathers used in their experiments contained impurities (like dyes). They cut off all kinds of beards and mounted the feathers on an absorption substrate. They then infused the feathers with common dyes by pipeling the dye solution directly on them and letting them dry. The feathers have been stained many times in some cases. Then they pumped the samples with pulses of light and measured any resulting emissions.
The team observed laser emissions in two separate wavelengths for all colored regions of the feathers of the feathers, with the green colored regions emitting the most intense laser. However, they did not observe any laser -emission of feathers, which were only stained once, only in sample feathers that experienced multiple wet and complete drying cycles. This is probably due to the better spread of dye and solver into the beards, as well as possible loosening of the fibrils in the keratin lining.
The authors were unable to identify the exact microstructures responsible for letting; It does not appear to be because of the keratin-coated melatonin sticks. Co -author Nathan Dawson of Florida Polytechnic University suggested to science That protein granules or similar small structures in the feathers could function as a laser cavity. He and his colleague think that one day, their work could lead to the development of biocompatible lasers, which could safely be inserted into the human body for feeling, imaging and therapeutic purposes.
This story originally appeared in Ars Technica.
