Researchers have constructed a laser diode capable of generating approximately 100-W, picosecond-range pulses by using an AlGaAs layer as a potential barrier between the structure's PN junction and gain region. The barrier slows down the accumulation of charge carriers in the gain region, prohibiting it from reaching its threshold limit before a high pumping current of 10⁵ A/cm² -- and a resulting 10³-V/cm electric field -- is achieved.

The team, from the University of Oulu in Finland and Inject enterprise in Saratov, Russia, reported in the June 17 issue of Applied Physics Letters that such lasers may someday provide a compact alternative for applications such as laser tomography and time-imaging spectroscopy, which now require solid or dye microcavity lasers.