It seems that scientists at the University of Alabama designed and made a material that changes the speed of light in a new, and more effective way than previous methods did.
The research was done by two professors and three grad students in the UA College of Engineering who managed to create the prototype for the next-generation optical networks and sensors that obviously transmit data via variances in the speed of light. Sources: Softpedia, Phys.org, Nanowerk, The News on Time, Lab Manager, Medical Design Briefs