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We present first results from a number of experiments conducted on a 0.53 kg cylindrical dumbbell-shaped sapphire crystal. This is the first reported optomechanical experiment of this nature utilising a novel modification to the typical cylindrical architecture. Mechanical motion of the crystal structure alters the dimensions of the crystal, and the induced strain changes the permittivity. These two effects result in parametric frequency modulation of resonant microwave whispering gallery modes that are simultaneously excited within the crystal. A novel low-noise microwave readout system is implemented allowing extremely low noise measurements of this frequency modulation near our modes of interest, having a phase noise floor of -165 dBc/Hz at 100 kHz. Fine-tuning of the crystals suspension has allowed for the optimisation of mechanical quality factors in preparation for cryogenic experiments, with a value of Q=8 x 10^7 achieved at 127 kHz. This results in a Q x f product of 10^13, equivalent to the best measured values in a macroscopic sapphire mechanical system. Results are presented that demonstrate the excitation of mechanical modes via radiation pressure force, allowing an experimental method of determining the transducers displacement sensitivity df/dx, and calibrating the system. Finally, we demonstrate parametric back-action phenomenon within the system. These are all important steps towards the overall goal of the experiment; to cool a macroscopic device to the quantum ground state at millikelvin temperatures.
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 fr
Here we present the design and implementation of a novel frequency synthesizer based on low phase noise digital dividers and a direct digital synthesizer. The synthesis produces two low noise accurate and tunable signals at 10 MHz and 100 MHz. We rep
Cooling of a 58 MHz micro-mechanical resonator from room temperature to 11 K is demonstrated using cavity enhanced radiation pressure. Detuned pumping of an optical resonance allows enhancement of the blue shifted motional sideband (caused by the osc
A novel interferometric method for absolute beam energy measurement is under development at MAMI. At the moment, the method is tested and optimized at an energy of 195 MeV. Despite the very small statistical uncertainty of the method, systematic effe
We have developed a mechanical absolute-rotation sensor capable of resolving ground rotation angle of less than 1 nrad$/sqrt{text{Hz}}$ above $30$ mHz and 0.2 nrad$/sqrt{text{Hz}}$ above $100$ mHz about a single horizontal axis. The device consists o