Nr. I11 - Metrology with frequency comb lasers

Approved Industrial Partnership Programme

Number	I11.
Title	Metrology with frequency comb lasers (MFCL)
Executive organisational unit	BUW
Programme management	Prof.dr. W. Ubachs
Duration	2006-2010
Cost estimate	M€ 1.1
Partner(s)	NMi, TNO, ASML

Objectives

The aim of the programme is to apply frequency comb lasers in precision frequency and length measurements and further develop and improve these advanced systems in terms of wave­length range, compactness and intensity. The objectives of the major industrial partner in the consortium (The Netherlands Measurement Institute - NMi) are to lay the foundations for future atomic clocks and operational length standards, and to establish and develop know­ledge on frequency combs in the Netherlands. The objective of TNO Science and Industry is to support and promote development of frequency comb lasers for 'space-based' applications.

Background, relevance and implementation

The invention of the principle of the self-referenced frequency comb laser has brought a revolution in metrology. A frequency comb acts as a bridge between optical frequencies (hundreds of THz) and frequencies in the radio-frequency domain. Where in previous days cumbersome procedures with labs full of equipment were required to measure optical frequencies relative to standards such as atomic clocks, now a direct connection can be established through an elegant and compact device: a phase-locked and carrier-envelope stabilized femto-second pulsed laser. Whether the future standard will be based on a (single) ion confined in a trap, or a laser-cooled sample of ultra-cold atoms in an optical lattice is an issue of debate in the metrological community, and a topic of advanced research.
Conversely, frequency combs connected to an established frequency standard can be employed to measure transition frequencies in atomic and molecular systems at the highest accuracy, and therewith test the fundamentals of physical law. Frequency comb technology may also have a significant impact in the field of length measurement as well. Length stan­dards and length measurement procedures are becoming increasingly important in various domains of physics and technological application.
Frequency combs may revolutionize this field by providing the extremely stable and accurate laser modes, that are required for interferometry. The further technological development of the frequency-comb laser principle could also lead to the availability of a compact spatially-coherent white light source with numerous applications in optical instrumentation.
The research will be executed on three locations: VU, TUD and NMi. The VU group of Prof. Ubachs will focus on frequency metrology ions in ion traps and the TUD group of Prof. Urbach on length metrology with phase-coherent pulses. Both groups will work in close cooperation with NMi.