Hardware and software solutions to noise in resonance measurements

Resonance measurements have the benefit that the system itself is a natural signal amplifier with a gain proportional to the quality factor (Q) of the resonator. However, even this small respite from Murphy’s law is not always enough to coax weak resonance signals out of a noisy background. In this talk I will discuss several aspects of improving signal to noise ratios in resonant ultrasound spectroscopy measurements using both hardware and software based solutions such as custom low-noise preamplifiers, lock-in amplifiers, dynamic averaging during data acquisition, and nonlinear fitting of noisy and overlapping (low-Q) peaks to an analytical model. Some particular issues of signal transmission across high-thermal gradients will also be discussed.