The device could help bring about "quantum communications" networks, which would use individual particles of light to send bits of information. Because each bit of information can be embedded in the quantum properties of a single photon, the laws of quantum mechanics make it difficult, if not impossible, for an enemy to intercept the message undetected.

Both the telecommunications and computer industries would like such networks to keep information secure. The NIST method may help overcome one of the technical barriers standing in their way by measuring photons' spectral properties—essentially their color—10,000 times better than conventional spectrometers.

Individual photons have a limitation: They cannot travel through fiber-optic cables for more than about 100 kilometers (about 60 miles) without likely being absorbed. A quantum network able to handle worldwide communications would need periodic way stations that could catch photons and retransmit their information without loss. The NIST team's invention could help such a "quantum repeater" interact effectively with photons.