Related papers: Dynamic thermal sensitivity of microwave cryogenic…
The Cryogenic Sapphire Oscillator is today recognized for its unprecedented frequency stability, mainly coming from the exceptional physical properties of its resonator made in a high quality sapphire crystal. With these instruments, the…
Here, we study the paramagnetic ions behavior in presence of a strong microwave electromagnetic field sustained inside a cryogenic sapphire whispering gallery mode resonator. The high frequency measurement resolution that can be now…
The cryogenic sapphire oscillator (CSO) is a highly specialized machine, which delivers a reference signal exhibiting the lowest frequency fluctuations. For the best units, the Allan deviation (ADEV) is <1e-15 for integration time between 1…
We report on the development of a sapphire cryogenic microwave resonator oscillator long-term fractional frequency stability of 2x10^-17Sqrt[\tau] for integration times \tau>10^3 s and negative drift of about 2.2x10^-15/day. The short-term…
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…
We show that fast technical fluctuations of microwave signals can be strongly suppressed by cryogenic resonators. The experiments were carried out with sapphire resonators cooled to approximately 6 K at frequencies around 11 GHz. Each…
We report on the measurement and characterization of power to frequency conversion in the resonant mode of a cryogenic sapphire loaded cavity resonator, which is used as the frequency discriminating element of a loop oscillator circuit.…
This article reports on the long-term frequency stabilty characterisation of a new type of cryogenic sapphire oscillator using an autonomous pulse-tube cryocooler as its cold source. This new design enables a relative frequency stability of…
The frequency stability of lasers is limited by thermal noise in state-of-the-art frequency references. Further improvement requires operation at cryogenic temperature. In this context, we investigate a fiber-based ring resonator. Our…
We report on the evaluation of microwave frequency synthesis using two cryogenic sapphire oscillators developed at the University of Western Australia. A down converter is used to make comparisons between microwave clocks at different…
We studied how the cryogenic sapphire resonator responds to fast variations of the dissipated microwave power. The experiments were carried out with sapphire resonators cooled to 6 K at frequencies around 11 GHz. We found that the…
A low maintenance long-term operational cryogenic sapphire oscillator has been implemented at 11.2 GHz using an ultra-low-vibration cryostat and pulse-tube cryocooler. It is currently the world's most stable microwave oscillator employing a…
Two nominally identical ultra-stable cryogenic microwave oscillators are compared. Each incorporates a dielectric-sapphire resonator cooled to near 6 K in an ultra-low vibration cryostat using a low-vibration pulse-tube cryocooler. The…
The thermal fluctuation of mirror surfaces is the fundamental limitation for interferometric gravitational wave (GW) detectors. Here, we experimentally demonstrate for the first time a reduction in a mirror's thermal fluctuation in a GW…
Progress in the emerging field of engineered quantum systems requires the development of devices that can act as quantum memories. The realisation of such devices by doping solid state cavities with paramagnetic ions imposes a trade-off…
The frequency stability of a laser locked to an optical reference cavity is fundamentally limited by thermal noise in the cavity length. These fluctuations are linked to material dissipation, which depends both on the temperature of the…
In recent years there has been considerable interest in exploiting the temperature dependence of sapphire whispering gallery mode frequency to develop a mechanically stable, high accuracy temperature sensor. Disk-resonator-based devices…
To create a stable signal from a cryogenic sapphire maser frequency standard, the frequency-temperature dependence of the supporting Whispering Gallery mode must be annulled. We report the ability to control this dependence by manipulating…
Dielectric resonators are key components for many microwave and millimetre wave applications, including high-Q filters and frequency-determining elements for precision frequency synthesis. These often depend on the quality of the dielectric…
We studied noise properties of microwave signals transmitted through the cryogenic resonator. The experiments were performed with the 11.342 GHz sapphire loaded cavity resonator cooled to 6.2 K. Based on the measured transmission…