Researchers at NIST have developed a new method to extend the operating range of microcombs to shorter near-infrared wavelengths, specifically around 1,064 nm. This breakthrough could enable more detailed imaging of biological samples and improved studies of oxygen levels and metabolic rates in tissues.
Microcombs are chip-scale devices that generate and measure light frequencies with high precision. Their typical operation is limited to a narrow range of near-infrared wavelengths around 1,550 nm. The new method allows scientists to independently tailor the microcomb’s central wavelength, intensity, and frequency separation.
The team achieved this by creating a microresonator with tiny, periodic bumps or corrugations along its circumference, transforming it into a photonic crystal. This structure provides additional control over the frequency range of the microcomb. The new capability could enable scientists to take clearer images of biological and biomedical samples, and to study oxygen levels and metabolic rates in skin and muscle during exercise.
The research was published in Applied Physics Letters Photonics.
Keywords: Microcomb, Photonic crystal, Near-infrared wavelengths, Optical communications, Frequency comb
