Ultrafast Laser Pulses Could Lead To Lightwave Computers
Everybody wants their computer to run faster, but we are approaching theoretical limits on just what traditional silicon-based electronics are capable of. For faster speeds, new technologies will need to be developed, and they may take advantage of some unusual physics. Researchers at the University of Michigan have made a discovery that could lead to these faster computers by way of lightwave electronics.
In lightwave electronics, electrons are manipulated by an oscillating electric field generated by ultrafast laser pulses, causing them to move at high speeds in certain directions. In modern electronics, when one fast moving electron hits another heat is produced, but with lightwave electronics the electrons are moving so quickly they are not likely to strike another before they stop. What the Michigan researchers have done is demonstrated this ability to move electrons in a semiconductor using pulses less than 100 femtoseconds long of terahertz radiation. These pulses pumped enough energy into the electrons to pop them up to a higher energy level, allowing them to move around the semiconductor crystal. The paths the electron take is not random though, or even determined by the laser pulses but by the structure of the crystal. When the electrons fall back down to a lower energy level, they emit light as an even shorter pulse than the terahertz source and these pulses could actually be used to read and write information to other electrons.
Eventually we could see lightwave computers operating ten to 100,000 times faster than modern computers, but there is still a lot to do before then. Before then we may see this used to optimize chemical reactions and in quantum systems, including quantum cryptography.
Source: University of Michigan