Terahertz pulse increases electron density 1,000-fold

Terahertz pulse increases electron density 1,000-fold: Working with standard semiconductor material (gallium arsenide, GaAs), the team observed that exposing the sample to a terahertz (1,000 gigahertz) range electric field pulse caused an avalanche of electron-hole pairs (excitons) to burst forth. This single-cycle pulse, lasting merely a picosecond (10-12 s), resulted in a 1,000-fold increase in exciton density compared with the initial state of the sample...
"Since terahertz waves are sensitive to water, our goal is to create a microscope that will allow us to look inside living cells in real time," says Prof. Tanaka.