High-Performance Optical Frequency References for Space

Thilo Schuldt,Alexander Milke,Evgeny V Kovalchuk,Norman Gürlebeck,Martin Gohlke,Claus Braxmaier,Josep Sanjuan,Klaus Döringshoff,Achim Peters

doi:10.1088/1742-6596/723/1/012047

Abstract

A variety of future space missions rely on the availability of high-performance optical clocks with applications in fundamental physics, geoscience, Earth observation and navigation and ranging. Examples are the gravitational wave detector eLISA (evolved Laser Interferometer Space Antenna), the Earth gravity mission NGGM (Next Generation Gravity Mission) and missions, dedicated to tests of Special Relativity, e.g. by performing a Kennedy- Thorndike experiment testing the boost dependence of the speed of light. In this context we developed optical frequency references based on Doppler-free spectroscopy of molecular iodine; compactness and mechanical and thermal stability are main design criteria. With a setup on engineering model (EM) level we demonstrated a frequency stability of about 2·10-14 at an integration time of 1 s and below 6·10-15 at integration times between 100s and 1000s, determined from a beat-note measurement with a cavity stabilized laser where a linear drift was removed from the data. A cavity-based frequency reference with focus on improved long-term frequency stability is currently under development. A specific sixfold thermal shield design based on analytical methods and numerical calculations is presented.

Highlights

High-performance optical frequency references are an essential tool for many applications in metrology, spectroscopy and fundamental physics
Examples are the gravitational wave detector eLISA, the Earth gravity mission Next Generation Gravity Missions (NGGM) ( Generation Gravity Mission) and missions, dedicated to tests of Special Relativity, e.g. by performing a KennedyThorndike experiment testing the boost dependence of the speed of light. In this context we developed optical frequency references based on Doppler-free spectroscopy of molecular iodine; compactness and mechanical and thermal stability are main design criteria
We presented our current efforts in realizing compact setups of frequency references based on Doppler-free spectroscopy of molecular iodine and on an optical resonator for future applications in space

Summary

Introduction

High-performance optical frequency references are an essential tool for many applications in metrology, spectroscopy and fundamental physics. In this context we developed optical frequency references based on Doppler-free spectroscopy of molecular iodine; compactness and mechanical and thermal stability are main design criteria.

Results

Conclusion