Artist’ conception of a computer chip made of light
 
In quantum mechanics, photons cannot interact each other in free space. Light waves have only through each other without changing their state or , until now.

Vienna University of Technology researchers have discovered a method to force photons to interact with each other using ultra thin glass fiber and a resonator. The photon is introduced into the resonator and directed in a , not unlike the motion of pendulum, and interacts with the glass fiber. The movement causes a 180 inversion in the photon. Light is from entering the resonator which prevents the photon from oscillating back to it’s original state.

In preventing light from entering the resonator, a maximum entangled state of photons can be which is necessary for feats such as , or transistors made of light, which can be used for quantum computing. 

Greg Giles