High resolution spectroscopy using fiber laser frequency combs

The output of a femtosecond fiber laser can be both spectrally broadened and stabilized, thereby providing a broadband coherent source in the near infrared. In the frequency domain, the result is a frequency comb with frequency stabilities at the millihertz level (relative to the reference), while in the time domain, the result is an optical pulse train with sub-femtosecond relative timing jitter. This coherent source can be used for high-resolution measurements in a range of areas including frequency metrology, ranging, vibrometry, and spectroscopy. We will discuss the performance of these sources, focusing on recent work applying them to high-resolution spectroscopy. This contribution of NIST, an agency of the US government, is not subject to copyright.