A New Method Creates More Pure Photonic Crystals
29 July 2014
A team of researchers from Princeton University and Columbia University have demonstrated a new method to create purer, defect-free photonic crystals using colloidal suspension.
In their research, published in Nature Communications journal, the scientists created a computer model revealing their technique. It involves adding precisely-sized chains of polymers to a colloidal suspension - something that had been thought possible for a while.
The new method marks a new way to create a perfect crystal - one is able to split light for an optical circuit. According to Princeton professor of chemical and biological engineering, Athanassios Panagiotopoulos, the key to the new technique was in fact the use of cheaper ingredients.
Instead of relying on synthesized particles with narrowly tailored directional interactions, as were previously used, the new method explores the possibility that tiny amounts of polymer trapped between the crystal's colloids can determine the stability of the crystal. These tiny traces of polymer were discovered by the team after analyzing the equilibrium state of different possible crystal shapes using the principles of thermodynamics.
As the crystals form, the trace amounts of polymer remain trapped within them and provide scientists with a way to determine the energy state of each crystal, because the polymers have role in determining its shape. According to the team's lead researcher, Nathan Mahynski, scientists now need to understand how the polymer interacts with the colloids, which will help them create any crystal they desire.