The wings of the morpho butte y demonstrate an iridescent blue color over wide viewing angles. The mechanism that generates this blue color is studied. Optical and transmission electron microscopy of the butte y wings reveal a complex wing structure with as many as 24 layers with periodic structures. The color generation is caused by interference of the multilayer structure as well as diffraction. It is possible to specially design grating structures so that a specific blue color can be generated and observed over wider angles. To demonstrate the grating concept, complex multigratings are designed and fabricated with electron-beam lithography. The light-diffraction properties of these gratings are presented.
© 2003 Optical Society of America
(050.1950) Diffraction and gratings : Diffraction gratings
(220.2740) Optical design and fabrication : Geometric optical design
(220.4000) Optical design and fabrication : Microstructure fabrication
Teh-Hwa Wong, Mool C. Gupta, Bruce Robins, and Thomas L. Levendusky, "Color generation in butte y wings and fabrication of such structures," Opt. Lett. 28, 2342-2344 (2003)