Tiny and Tunable
The telecommunications industry has big plans to dramatically increase information-carrying capacity by using multiple colors of light in an optical fiber. Great idea, but its practicality depends on a laser that can be “tuned” to different wavelengths. Constance Chang-Hasnain, professor of electrical engineering at the University of California at Berkeley, may have an answer.
A laser’s color can be changed by resizing its “resonant cavity”-the space in which photons bounce back and forth before emerging as a beam. In Chang-Hasnain’s device, a small increase in voltage causes a tiny cantilever arm to lower a mirror toward the chip-shrinking the resonant cavity and shortening the wavelength. The device can now be tuned across wavelengths spanning about 30 nanometers. Chang-Hasnain aims to triple that, making possible hundreds of separate communications channels.
Deep Dive
Uncategorized
Our best illustrations of 2022
Our artists’ thought-provoking, playful creations bring our stories to life, often saying more with an image than words ever could.
How CRISPR is making farmed animals bigger, stronger, and healthier
These gene-edited fish, pigs, and other animals could soon be on the menu.
The Download: the Saudi sci-fi megacity, and sleeping babies’ brains
10 Breakthrough Technologies 2023
Stay connected
Get the latest updates from
MIT Technology Review
Discover special offers, top stories, upcoming events, and more.