I’ve mentioned the importance of new materials on a few occasions previously in this blog. Steel allowed skyscrapers, light weight metals took us to the air and moon, semiconductors allowed the dawn of the computer age, and – well – you get the idea. One such class of materials that is exponentially increasing in importance is that of photonic crystals.
At its root, a crystal is simply a material that has a very regular structure. The molecules are ordered in a specific way that repeats over and over. A single crystal is a chunk of material that has a perfect structure throughout its entire body. There are no defects, or structures at angles to each other. The single crystal is perfect.
Photonic crystals make use of this regular structure. As light passes through them, the specific structure of the molecules and properties of the material control the light in very specific ways. Prisms spread light into the visible spectrum. Fiber optic cables trap light and carry it down their entire length. Holograms create 3-D images by reflecting and directing light.
Now, scientists at the University of Illinois have created something new – an optoelectrically active 3-D photonic crystal.
I’d get into how they did it exactly, but this post is already technical enough. Sufficed to say that it’s the first time it’s been done and people have been trying for decades.
It ain’t easy.
The second part of that should be familiar by now. Instead of a flat structure that can be etched into substances like glass or semiconductors (for computers), the photonic crystal is a 3-D object. The physical structure allows it to control and manipulate light in more complicated ways. The optoelectrically active part of it means that it can convert light into electricity and vice versa.
So what does one do with an optoelectrically active 3-D photonic crystal?
Paul Braun used the new technology to create a 3-D photonic crystal LED. An LED is a light-emitting diode – you know, the light on your computer or your brand new HD television, for example – that works because of its internal structure. Electrons interact with electron holes within the device, releasing energy in the form of photons, more commonly known as light.
So in the new material, electricity comes in and light comes out, but in new and unique ways. One possible example would be a laser that does not have a power threshold. The tiniest amount of power will create a laser beam (typically there is a minimum amount of power needed before the light forms a cohesive beam.)
Other possible applications include improved solar collection for solar cells or even cloaking technology.
Look out Klingons and Romulans, we’re coming for your monopoly…