Amplifying Light with Electrical Pumping.

• Position: QUANTUM DOTS - Brief article

In a breakthrough development, scientists at Los Alamos (N.M.) National Laboratory have shown that light can be amplified using electrically excited films of the chemically synthesized semiconductor nano-crystals known as quantum dots. The quantum dot films are integrated into devices much like the now-ubiquitous light-emitting diodes (LEDs) but, in this case, designed to sustain the high-current densities required for achieving the optical-gain regime.

One sees laser diodes every day in laser pointers, barcode readers, and the like, and a key element of such devices is an optical-gain medium, which, instead of absorbing incident light, amplifies it.

"Optical gain with electrically excited quantum dots is now a reality," says Victor Klimov, head of the quantum dot team. "We have been working to develop new lasing media, using chemically synthesized quantum dots, although it had been widely...