October 24, 2018
One high-tech device that has been difficult to scale down effectively has been the optical spectrometer, which analyzes wavelengths of light to determine the chemical composition of an object. While nanomaterials have technically made it possible to reduce the size of spectrometers to the chip scale, these devices have not worked very well. Spectrometers must spread out wavelengths of light in order to be effective. The more you scale down the size of a spectrometer, the more you degrade its performance, because the light cannot be spread out enough.
Researchers at MIT have found a way around this problem with a new approach to manipulating light on a chip-scale spectrometer. They’ve used optical switches that send the light down different pathways of varying lengths and, in so doing, have made on-chip spectrometers that rival the performance of their large-scale cousins in terms of spectral resolution and channel count, as well as signal-to-noise ratio.