To be clear, it's not that they shoot laser beams from their feathers as some sort of mating ritual or defense mechanism (which, honestly, is probably how I would have used my own laser feathers, if I had them), but that there are strikingly identical nano structures that can reflect back a little bit of laser light, under laboratory conditions:
After staining the feathers with a common dye and pumping them with soft pulses of light, they used laboratory instruments to detect beams of yellow-green laser light that were too faint to see with the naked eye. They emerged from the feathers’ eyespots, at two distinct wavelengths.