Cryogenic Sapphire Oscillator using a low-vibration design pulse-tube cryocooler: First results

Abstract

A Cryogenic Sapphire Oscillator has been implemented at 11.2 GHz using a low-vibration design pulse-tube cryocooler. Compared with a state-of-the-art liquid helium cooled CSO in the same laboratory, the square root Allan variance of their combined fractional frequency instability is ${\sigma }_y=1.4\times 10^{-15}{\tau }^{-1/2}$ for integration times $1<\tau <10$ s, dominated by white frequency noise. The minimum ${\sigma }_y=5.3\times 10^{-16}$ for the two oscillators was reached at $\tau =20$ s. Assuming equal contributions from both CSOs, the single oscillator phase noise $S_{\varphi }\approx -96dBra{d}^2/Hz$ at 1 Hz offset from the carrier.

5 pages, 5 figures, accepted in IEEE Trans on Ultrasonics, Ferroelectrics and Frequency Control

References in corpus (5)

• 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 using Rotating Cryogenic Sapphire Oscillators
• Cryogenic sapphire oscillator with exceptionally high long-term frequency stability
• Long Term Operation and Performance of Cryogenic Sapphire Oscillators

Cited by in corpus (10)

• Progress in Atomic Fountains at LNE-SYRTE
• Ultra-low-phase-noise cryocooled microwave dielectric-sapphire-resonator oscillators with 1 x 10^-16 frequency instability
• Ultra-low vibration pulse-tube cryocooler stabilized cryogenic sapphire oscillator with 10^-16 fractional frequency stability
• Advanced noise reduction techniques for ultra-low phase noise optical-to-microwave division with femtosecond fiber combs
• The Impact of Frequency Standards on Coherence in VLBI at the Highest Frequencies
• Frequency Stability Measurement of Cryogenic Sapphire Oscillators with a Multichannel Tracking DDS and the Two-Sample Covariance
• Tests of Sapphire Crystals Produced with Different Growth Processes for Ultra-stable Microwave Oscillators
• High Resolution Flicker-Noise-Free Frequency Measurements of Weak Microwave Signals
• Ultra stable and very low noise signal source using a cryocooled sapphire oscillator for VLBI
• Comparison of ultra-stable radio frequency signals synthesized from independent secondary microwave frequency standards