Supervisor: Lute Maleki

Ultra-stable frequency technologies are an essential part of NASA's Deep Space Network, enabling accurate navigation of spacecraft far from the earth's orbit. They also make possible many kinds of radio science, from the Very Long Baseline Interferometry (VLBI) that determines the exact position of the earth's center, to measurements of the solar wind, to characterization of the rings of Saturn. Future NASA missions are planned that will use the most stable frequency standards to probe the structure of space-time itself.

JPL's Quantum Sciences and Technology Group develops technologies that improve NASA's capability to generate, transmit, compare and analyze spacecraft signals with unparalleled accuracy and resolution.

Trapped Ion Frequency Standard This new generation of atomic frequency standards was developed at JPL and is now being installed in DSN ground stations. Small size and high reliability also make it a natural choice to advance spacecraft capabilities to the ultra-high stability level (10-15 or better).

Photonics Reference frequencies are transmitted throughout the DSN by fiber optic cables. Semiconductor laser techniques now add a new dimension for ultra-stable transmission, conversion and generation of microwave signals.

Ultra-Stable Microwave Oscillators Short-term microwave oscillators complement the medium and long term capabilities of present day atomic standards. Cryogenic sapphire and ruby resonators are used in the latest version that boasts continuous operation with a commercial cryocooler.

Noise Analysis and Statistics Characterization of the stability for any frequency standard requires mathematical tools to analyze the noise processes that give rise to instabilities. Tools such as the Allan Deviation and Noise Spectral Density are evaluated as to their utility and completeness, and are implemented in our Test Facility.

Laser Cooling One of the most exciting developments in physics over the past 15 years has been the use of lasers to cool atoms to ultra-low temperatures. We are developing a state-of-the-art laser cooling facility with the ability to cool and trap a variety of both neutral and charged atoms.

Related Links:

• Frequency and Timing Advanced Development Group
• National Institute for Standards and Technology
• U.S. Naval Observatory
• IEEE UFFC Frequency Control
• Paris Observatory
• National Physical Laboratory (England)
• Istituto Elettrotecnico Nazionale (Italy)
• National Research Council (Canada)
• JPL DSN Technology Program

Web Pages maintained by John Dick Updated 10/00