Optical metrology articles from across Nature Portfolio

While numerical simulations for metalenses frequently show efficiencies above 90% at low numerical apertures, the experimental counterpart struggles to reach such efficiencies. The authors modify the model for prediction and systematically realise a set of high-precision meta-lenses with high efficiencies across the whole numerical aperture range.

While MHz repetition rates at modern X-ray free-electron laser (XFEL) facilities achieve remarkable capabilities for imaging, the high repetition rates may also lead to new stability problems. The authors experimentally demonstrate that thermoelastic displacements between successive pulses can be detrimental to the performance of cavity-based XFEL

We demonstrate a photon-counting approach that extends the unique advantages of spectroscopy with interfering frequency combs into regions where nonlinear frequency conversion tends to be very inefficient, providing a step towards precision broadband spectroscopy at short wavelengths and extreme-ultraviolet dual-comb spectroscopy.

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.