Single nanowire makes tiniest spectrometer

Abstract

Meet the world’s smallest optical spectrometer. Crafted from a single nanowire less than 100 µm long, the device can measure the intensity of colored light across the visible spectrum and may eventually lead to miniature spectrometers that could be installed in a cell phone (Science 2019, DOI: 10.1126/science.aax8814). “Our spectrometer is about 1,000 times smaller than any previous spectrometer that people have demonstrated,” says Tawfique Hasan at the University of Cambridge who is part of the team that built the device. Scientists routinely use optical spectrometers to study the composition of materials, including the atmospheres of exoplanets and human tissue samples. Advances in electronics and optics have already delivered handheld spectrometers. But building spectrometers that are even smaller—less than a few millimeters wide—is a huge challenge, Hasan says, not least because of the difficulty of miniaturizing optical components like interference gratings that split white light into its component c...