Limitations due to residual interference in a fiber-based optical frequency reference at 1.55 μm

We present an experimental investigation of the stability limits specific to optical frequency standards using fiber optic architecture and semiconductor lasers. A compact setup composed of a semiconductor laser frequency-locked onto an acetylene transition detected in saturated absorption has been implemented using only fiber optic components. Fiber optic technology allows compact and reliable solutions for various applications. However, for high sensitivity and stability applications such as metrology, residual reflections induced, by optical index inhomogeneities in connectors and fiber-coupled components leading to spurious interference significantly limit performance. We have examined the origin of the interference fringes superimposed on the detected signal and the limitations they cause to the frequency stability of the reference. The effects of temperature and beam power fluctuations are also examined. Our results show that the frequency stability is limited in the 10(-13) range by the effect of interference fringes due to use of fiber components. (C) 2022 Optical Society of America

Automated summary

In this study, the stability limits specific to optical frequency standards using fiber optic architecture and semiconductor lasers were experimentally investigated. It was found that residual reflections induced by optical index inhomogeneities significantly limit the performance, and interference fringes impose limitations on the frequency stability of the reference.