Abstract

We have developed an optical frequency standard at 1.5 μm based on detecting an acetylene transition by saturation spectroscopy in an absorption cell [1]. With the aim to achieve a compact device combining stability and transportability, the setup is entirely composed of fibered components, except for the acetylene cell. The main limitation to reaching a long-term stability level in the 10^-14 range is interference fringes [1, 2]. We describe here an original method based on the detection of the error signal at a frequency which is not modulating the interference. We also study the benefit of a multi-pass geometry for the acetylene cell in order to both improve the SNR of the detected signal and reduce the volume.

© 2023 IEEE