Danish National Metrology Institute 
DFM 
(Danish Fundamental Metrology) is the Danish national metrology institute. DFM’s main activities are related to development and maintenance of measurement standards and techniques for support of the Danish metrology infrastructure. Despite being a small metrology institute with a permanent staff of 23 persons, DFM covers the fields of electricity, length, optics, nano scale metrology, acoustics, mass and electrochemistry. Frequency stabilised lasers are essential tools in the fields of optics and length metrology. Various types of frequency stabilised lasers are used in DFM’s commercial calibration activities. Current research activities include development of new types of frequency stabilised lasers, which are sufficiently compact and robust to be used in industrial applications. In particular, DFM has been investigating gas-filled hollow-core fibres as potential candidates for such optical frequency references.
Integrated, fibre based frequency standard
This project focuses on optical frequency standards based on gas-filled hollow-core fibres with industrial applications. Gases include molecular gasses with resonances in the telecom range targeted at industry as well as Rb atoms. The potential use of two-photon transitions in Rb for compact secondary frequency standards will be explored. The frequency stability in the 1 Hz to 100 kHz bandwidth will be addressed by combining the atomic/molecular references with compact optical resonators.
The researcher will work at DFM and enrol in a PhD program at the DTU (Danish Technical University), supervised by Professor Ole Bang.
