Long Term Operation and Performance of Cryogenic Sapphire Oscillators

Abstract

Cryogenic Sapphire Oscillators (CSO) developed at UWA have now been in operation around the world continuously for many years. Such oscillators, due to their excellent spectral purity are essential for interrogating atomic frequency standards at the limit of quantum projection noise; otherwise aliasing effects will dominate the frequency stability due to the periodic sampling between successive interrogations of the atomic transition. For this reason, UWA oscillators are now operational at NMI (Sydney), LNE-SYRTE (Paris), the French Space Agency (CNES, Toulouse) and at UWA (Perth). Other applications, which have attracted attention in recent years, include tests on fundamental principles of physics, such as tests of Lorentz invariance. This paper reports on the long-term operation and performance of such oscillators. We compare the long-term drift of some different CSOs. The drift rates turn out to be linear over many years and in the same direction. However, the magnitude seems to vary by more than one order of magnitude between the oscillators, ranging from 10^14 per day to a few parts in 10^13 per day.

Accepted for publication in IEEE Trans. UFFC 21st June 2006

References in corpus (6)

• Tests of relativity using a microwave resonator
• Test of Lorentz Invariance in Electrodynamics Using Rotating Cryogenic Sapphire Microwave Oscillators
• Improved Test of Lorentz Invariance in Electrodynamics
• Whispering Gallery Resonators and Tests of Lorentz Invariance
• Cryogenic sapphire oscillator with exceptionally high long-term frequency stability
• Rotating Resonator-Oscillator Experiments to Test Lorentz Invariance in Electrodynamics

Cited by in corpus (12)

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• Testing Local Lorentz and Position Invariance and Variation of Fundamental Constants by searching the Derivative of the Comparison Frequency Between a Cryogenic Sapphire Oscillator and Hydrogen Maser
• Nano-Kelvin thermometry and temperature control: beyond the thermal noise limit
• Ultra-stable laser with average fractional frequency drift rate below $5\times 10^{-19}/\mathrm{s}$
• Contributing to TAI with a Secondary Representation of the SI Second
• Adapting a Cryogenic Sapphire Oscillator for Very Long Baseline Interferometry
• Improved Constraints on Isotropic Shift and Anisotropies of the Speed of Light using Rotating Cryogenic Sapphire Oscillators
• Ultra-low vibration pulse-tube cryocooler stabilized cryogenic sapphire oscillator with 10^-16 fractional frequency stability
• Cryogenic Sapphire Oscillator using a low-vibration design pulse-tube cryocooler: First results
• Why do we Still Believe in Newton's Law ? Facts, Myths and Methods in Gravitational Physics
• Tailoring the Stability of a Two-Color, Two-Photon Rubidium Frequency Standard
• A Cryogenic Sapphire Resonator Oscillator with 1e-16 mid-term fractional frequency stability