Optical metrology articles from across Nature Portfolio

A sub-cycle modulation in reflectivity is observed in bulk crystals subjected to intense laser fields. The effect provides a new way to probe attosecond dynamics in materials.

Launched 2 years ago, the Deep-Space Atomic Clock (DSAC) mission has exceeded expectations for the first mercury ion clock in space, demonstrating a long-term stability beyond the current performance of other space clocks.

A chip-based optical frequency comb has enabled the realization of a 300 GHz signal with record low phase noise. The development could yield ultra-compact, ultra-low-noise sources for millimetre-wave applications in telecommunications, remote sensing and precision spectroscopy.

Observing accreting black holes in the early Universe allows precise comparison of clocks over intercontinental distances on Earth. This is achieved with a novel observation strategy using the next generation of very long baseline interferometry systems.

Optical clocks held at slightly different heights provide a stringent test of general relativity comparable to space experiments and open new opportunities for clock-based geophysical sensing.