Transistors have long served as the building blocks of microelectronics. More recently, microchip lasers have been emerging as cornerstones of light-based circuitry, or photonics. Now, engineers have melded the two types of components into one miniature device that both amplifies electric current and emits a narrow beam of single-wavelength light.
"It's simultaneously a transistor and a laser. It's a transistor laser," says co-developer Nick Holonyak Jr. of the University of Illinois at Urbana-Champaign. He previously contributed to the invention of various optoelectronics gadgets, including the fir