Spotlight: Chip-Scale Frequency Combs Can Be Integrated With Other Sensors

Frequency combs — specialized lasers that act like rulers to measure light — are now being brought down to a low-power, chip-scale form. NIST researchers David Long, Vladimir Aksyuk and their colleagues have developed frequency combs on a chip that can be integrated with other sensors, such as those for temperature and acceleration.

Frequency comb technology enables rapid measurements of different wavelengths of light, such as those absorbed by atoms and molecules, enabling scientists to look at how atomic and molecular systems are responding in real time.

Combining frequency combs on a chip with other integrated sensors can have uses in fields such as quantum sensing, which uses advanced sensor technology to detect changes in physical properties at the atomic level. In their demonstration, the researchers also fabricated a microring that operates as a temperature sensor, which they were able to read out with the comb.

While chip-scale frequency combs have been made before, the new design requires as little as one ten-millionth of the power of its predecessors. Most previous designs required devices known as acousto-optic modulators and electro-optic modulators to generate and utilize the frequency comb. This is a problem for chip-based devices because the fabrication methods for these two devices are often incompatible. In their work, the researchers removed the need for the acousto-optic modulator.

The work is part of the NIST on a Chip program, which seeks to bring cutting-edge measurement science technology to technical experts across academia and industry. 

Learn more about the scientific details of this technology in their latest paper.