In a breakthrough development, Los Alamos scientists have shown that they can successfully amplify light using electrically excited films of the chemically synthesized semiconductor nanocrystals 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.