Researchers have developed a nanoscale, highly efficient optical data, with the goal of significantly reducing energy consumption. (Electrical Engineering at Stanford University Image)

Researchers have developed a nanoscale, highly efficient optical data transmitter or semiconductor laser, the key to which is a multi-layered nanophotonic layered wafer, the holes of which are almost perfectly round with smooth interior walls and act like a hall of mirrors to reflect photons back toward the center of the laser. (Electrical Engineering at Stanford University Image)

Nanoscale Photonic-Crystal Lasers: 10 Times Faster, 1000 Times Less Energy

Published Dec. 13, 2011
By Ms. Molly Lachance, AFRL/AFOSR-PIP
Office of Scientific Research

ARLINGTON, Virginia -- Supercomputers consume super amounts of energy, and there is an ongoing technological solution to reduce that consumption. Funded in part by AFOSR, a Stanford University team unveiled a tiny, highly efficient semiconductor laser that could herald a new era in low-energy data interconnects that communicate with light as well as electrons.

The effort concerns a type of data transmitter known as a photonic-crystal laser that besides being fast and small, also operates at very low energy levels. The team has produced a nanoscale optical data transmitter - a laser - that uses 1,000 times less energy and is 10 times faster than the very best laser technologies in commercial use today. The laser is based on a multi-layered wafer of gallium arsenide, embedded with three thin layers of a second crystal, indium arsenide, with quantum dots within the wafer. When compiled, the nanophotonic layered stack is only 220 nanometers thick. At the heart of the wafer, photons are concentrated and amplified into a tiny ball of laser light which can be modulated up to 100 billion times per second (10 times the rate of the current top-rated data transmitters) with the light becoming binary data: light on for one; light off for zero. Hundreds of these nanophotonic transmitters could be arranged on a single layer, and many layers could then be stacked into a single chip.

While this new technology currently operates at relatively cold temperatures (about 190 degrees below zero Fahrenheit), the team is working toward perfecting operation at room temperature while maintaining energy efficiency at about 1,000 times less than today's commercial technologies.