Infinera packs dozens of optical components onto photonic integrated circuits for ultrafast optical networks.
fourteen 100-gigabit photonic integrated circuits sitting in a plastic carrier for performance testing
The company has demonstrated a 400-gigabit chip and is well along in the development of what it describes as the fastest optical chip in the world--a 1.6-terabit version that it expects to commercialize within several years. The four gold patches on the chip an astonishing total of 240 patterned optical components.
Optical devices are three-dimensional structures, far more challenging to manufacture than two-dimensional silicon transistors. Making the lasers, detectors, modulators, and other components of the finished chip requires repeatedly depositing and etching away many thin layers of different materials, such as indium gallium arsenide and indium phosphide.
The 1.6-terabit chip differs from the 100-gigabit version largely in the number of devices patterned onto it. Each 100-gigabit chips contains, among other components, 10 lasers, 10 detectors, 10 modulators (which encode data by switching light on and off), and 10 waveguides that direct photons into a multiplexer. The 1.6-terabit chip's 240 components include 40 lasers, 40 detectors, 40 modulators, and 40 channels. And each modulator encodes data four times as fast.
After the wafers come off the line, they are sliced into chips--several hundred of them.
The Infinera package--chips and circuit boards--take up one-fifth the space of conventional technology.