Skip to content. | Skip to navigation

Personal tools


UMR 5672

logo de l'ENS de Lyon
logo du CNRS
You are here: Home / Seminars / Experimental physics and modelling / Colloidal photonic glasses and the case of red

Colloidal photonic glasses and the case of red

Sofia Magkiriadou (James Frank Institute, Univ. Chicago, USA)
When Jan 05, 2016
from 10:45 to 12:00
Where Centre Blaise Pascal
Attendees Sofia Magkiriadou
Add event to calendar vCal

When a material has inhomogeneities at a length scale comparable to the wavelength of light, interference can give rise to structural colors: colors that originate from the interaction of the material’s microstructure with light and do not require absorbing dyes. One familiar way in which this occurs is Bragg scattering in photonic crystals, which have iridescent structural colors. However, long-ranged order is not necessary for structural color: glasses, which have only short-ranged order, can also be colorful. Unlike crystals, the structural colors of photonic glasses are independent of the viewing angle due to their disordered, isotropic structure. 

Nature has been employing this coloration mechanism for millions of years. However, to the best of our knowledge, there is no natural example of a red photonic glass. What is special about red? 

In this talk, we share our insights into this absence of red photonic glasses in nature. Based on experiments with colloidal glasses combined with scattering theory, we show that it can be explained by the wavelength-dependence of the single-particle scattering cross-section, which can override the interference condition set by the structure. We report on the experimental methods we have developed in order to make non-iridescent, structural red color. Finally, we begin an exploration of the color gamut that could be achieved with analogous techniques, and we entertain the prospect of using photonic glasses as a new type of long-lasting, non-toxic, and dynamically tunable pigment.  

More information about this event…