Frequency Comb Spectroscopy

Optical frequency combs have revolutionised time and frequency metrology by providing rulers in frequency space that can measure large optical frequency differences and/or link microwave and optical frequencies straightforwardly. Such combs enable precision laser spectroscopy and tests of fundamental physics, as well as providing the long-missing clockwork mechanism for optical clocks.

While frequency combs have become essential for research areas such as attosecond science and the calibration of astronomical spectrographs, one of their most successful applications beyond their original purpose is dual-comb interferometry. This involves forming an interferometer using two frequency combs with slightly different line spacing. Dual-comb interferometers without moving parts are fundamentally different from other types of interferometer: they perform direct frequency measurements without any geometric limitations to resolution. They outperform state-of-the-art devices in an increasing number of fields, including spectroscopy and three-dimensional imaging, and offer unique features such as high accuracy and precision at great speed. This talk will provide a brief introduction to optical frequency combs and survey dual-comb spectroscopy and its latest developments.