Ultra-precise length metrology using frequency-comb lasers
Although frequency combs can be used for attosecond pulse generation and ultra-high optical calibration, there are even more applications. A frequency comb laser emits pulses at a very well defined interval. This means that is can be used as a length ruler, because the speed of light in vacuum is defined to be 299 792 458 m/s. So if you can measure the time of flight of laser pulses very accurately, you can also tell the distance very accurately too (in vacuum at least).
Currently we have two projects that are related to this. The first one is a collaboration with Menlo Systems, NPL, and Kayser-Threde, to investigate the possibilities of frequency combs for long distance measurements in space. This is especially interesting for 'formation-flight' of satellites.
The other project is a collaboration with the Technical University Eindhoven (TUe), and involves modelocked laserdiodes as a possible source of miniature frequency combs. Funding is provided by Memphis. The idea is there to use quantum-dot lasers at 3-10 GHz repetition rate, and investigate their properties for frequency comb applications. The devices are produced at the TUe, and several of them have been brought to the LCVU for further testing and a comparison with a fiber-frequency comb laser (also recently installed).
More details will be given later for both projects.
The projects are funded by:
Questions? Contact: K.S.E.Eikema@vu.nl