YOUNGSTOWN, Ohio – You know peacocks as the large birds with brilliant blue and green iridescent tail feathers. Or maybe as the NBC television logo.
But researchers at Youngstown State University and Florida Polytechnic University discovered something unusual about the colorful birds. Male peacocks have lasers in their tail feathers. Yep, you read that right. Lasers. In peacock plumage.
The scientists dyed and repeatedly wet the feathers in the eyespots and allowed them to dry.
While wet and after wet/dry cycling, across multiple parts of the same feather, “a highly conserved set of laser wavelengths was observed,” the study reported.
The peer-reviewed journal Scientific Reports last month published the paper by three people from the Florida university, Nathan Dawson, a Florida Polytechnic physics professor who’s also an affiliate faculty member at YSU, and Erfan Nasirzadeh Orang, a YSU undergraduate who is studying computer science.
Two YSU faculty, Michael Crescimanno, a physics and astronomy professor; and C. Virgil Solomon, a professor in the mechanical engineering program, contributed to the study but declined author credit, Dawson said.
He said the work revealed that the laser light emitted is below the random laser threshold and is consistent across different colors. That indicates the cause is structural rather than color based.
The finding has many applications.
“So what this means is this opens a new door for the future of the bio lasers – so the type of the lasers that are compatible with the human body – and then could be implanted inside the body for sensing early signs of cancer or many applications,” Orang, a YSU honors student and teaching assistant, explained.
Crescimanno said there may be industrial applications as well.
“People have talked about essentially having something like a screen or a display that could use these bio structured materials as kind of an artificial color,” he said.
The feathers appear colorful, but there’s no pigment, Crescimanno said.
“That’s the point. It’s structural color,” he said. “And so you could imagine painting a wall with a bunch of structural color and having brilliant, beautiful things, but it’s all just proteins that are not dyes. And so they would just wash off or decompose in time.”
The color is produced by the interaction of light with the material at nanoscale.
“So it’s all just structural,” Orang said. “This is just a reflection that makes these colors. Light reflection bouncing from this surface gives the color because of the patterning …”
The study involved a disciplinary team with Crescimanno and Dawson from physics and Solomon from mechanical engineering.
Solomon has a background in electron microscopy, which is how he got involved.
“We needed to have some physical evidence of the features that create that reflection – the lights in the feather,” Solomon said.
Usually in working with natural materials, you need to work at the atomic level to see what’s not visible to the naked eye, he added.
“What the electron microscopy does, and my role is, is to make the invisible visible,” Solomon explained.
That’s how electron microscopy and atomic force microscopy operate. Those techniques allow scientists to see the features of the material that aren’t otherwise visible.
“They help us to explain the physical model that we developed to understand the optical phenomenon,” Solomon said.
The study was funded by a National Science Foundation grant and grew out of a bio photonics grant that Dawson and Crescimanno received.
Dawson is writing a grant to continue the research to determine what causes the emission they found.
“… Different colors usually mean different resonances, but yet we found the same thing in all the different color regions, which means it wasn’t the color that actually was causing it,” he said. “It was something else.”
Orang was excited about his author credit on the published paper and enjoys the work. He’s an international student from Iran who came to the U.S. in 2022 to study at YSU.
“And it’s been a great experience so far. I love it,” he said.
Orang is set to graduate in the spring and dreams of being a scientist.
He’s applying to graduate schools with hopes of continuing his education in this country. But he’s also considering schools in Europe and Canada, given the current situation in America.
He’s in the U.S. on an F-1 student visa but wrestles with daily uncertainty about his future.
Orang hoped to conduct more research this summer, but those opportunities fell through either because of his status or due to NSF funding cuts.
Being involved in the study solidified his plans to pursue a career in research.
“I learned a lot,” he said.
Pictured at top: Virgil Solomon, a professor in the mechanical engineering program at Youngstown State University, and Erfan Nasirzadeh Orang, a YSU undergraduate student, in a lab in Moser Hall.