A team of researchers from Lehigh University in the US have created terahertz pulses by frequency-mixing the beams from two carbon-dioxide lasers.

The carbon-dioxide lasers emitted beams at 10.59 µm and 10.26 µm with output powers of 11.9 kW and 11.1 kW respectively. The team focused the two beams into GaSe crystals with lengths varying between 2 and 47 mm.