Optical Frequency References for Space Applications

Paper number

IAC-18,A2,1,7,x45578

Author

Dr. Thilo Schuldt, Germany, German Aerospace Center (DLR), Bremen, Germany

Coauthor

Mr. Markus Oswald, Germany, University of Bremen

Coauthor

Mr. Martin Gohlke, Germany, DLR, German Aerospace Center

Coauthor

Mr. Klaus Döringshoff, Germany, Humboldt University of Berlin

Coauthor

Dr. Evgeny Kovalchuk, Germany, Humboldt University of Berlin

Coauthor

Dr. Ulrich Johann, Germany, Airbus DS GmbH

Coauthor

Prof. Achim Peters, Germany, Humboldt University of Berlin

Coauthor

Prof. Claus Braxmaier, Germany, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Institute of Space Systems

Year

2018

Abstract

Optical frequency references are a key technology for future space missions in fundamental physics, geoscience, Earth observation and navigation and ranging. Examples are the gravitational wave detector LISA (Laser Interferometer Space Antenna), the Earth gravity mission NGGM (Next Generation Gravity Mission) and missions testing Special Relativity such as BOOST (Boost Symmetry Test). Furthermore, future GNSS (Global Navigation Satellite Systems) will benefit from optical frequency references with higher performance in frequency stability, compared to the currently used microwave clocks.

We present our work on the development of frequency references based on Doppler-free spectroscopy of molecular iodine where special emphasis is put on compactness and robustness for space operation. We realized a setup on elegant breadboard level (EBB) on a 55 cm x 25 cm thermally and mechanically stable glass-ceramic base plate using a 30 cm long iodine cell in triple pass configuration [1] and a more compact system on engineering model level (EM) [2] using a specifically designed compact iodine cell in 9-pass configuration on a 38 cm x 18 cm fused silica base plate. Both setups show similar frequency stabilities at the 10-15  level at integration times between 10 s and 1000 s. The EM setup was subjected to thermal cycling and vibrations. In a recent activity, a spectroscopy unit for use on a sounding rocket mission has been developed and integrated [3]. 

Further steps with respect to space operation are presented, including mission proposals for testing special relativity and for technology demonstration of optical clock technologies for future GNSS.  
    
 [1]  T. Schuldt, K. Döringshoff, E. Kovalchuk, A. Keetman, J. Pahl, A. Peters, C. Braxmaier, “Development of a compact optical absolute frequency reference for space with 10-15 instability”, Applied Optics, vol. 56, p. 1101-1106, 2017.


[2]  K. Döringshoff, T. Schuldt, E.V. Kovalchuk, et. al., „A flight-like absolute optical frequency reference based on iodine for laser systems at 1064 nm”, Appl. Phys. B 123: 183, 2017. 


[3]  V. Schkolnik, K. Döringshoff, F.B. Gutsch, et al. „JOKARUS – design of a compact
optical iodine frequency reference for a sounding rocket mission“, EPJ Quantum Technol. 4: 9, 2017.

Abstract document

IAC-18,A2,1,7,x45578.brief.pdf

Manuscript document

IAC-18,A2,1,7,x45578.pdf (🔒 authorized access only).

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