Researchers at the Max Planck Institute of Quantum Optics (MPQ) have achieved a significant breakthrough in ultraviolet spectroscopy, enabling precise spectroscopy under starved-light conditions. This development promises advances in several scientific and technological fields, including tests of fundamental physics, quantum-electrodynamics theory, determination of fundamental constants, precision measurements, optical clocks, high-resolution spectroscopy, atmospheric chemistry, astrophysics, and strong-field physics.
The team, led by Nathalie Picqué, has demonstrated that dual-comb spectroscopy can be effectively employed in starved-light conditions, at power levels more than a million times weaker than those typically used. This breakthrough was achieved using two distinct experimental setups with different types of frequency-comb generators. The researchers developed a photon-level interferometer that accurately records the statistics of photon counting, showcasing a signal-to-noise ratio at the fundamental limit. This achievement highlights the optimal use of available light for experiments, and opens up the prospect of dual-comb spectroscopy in challenging scenarios where low light levels are essential.