A Novel Faint Signal Processing Method for Sensitivity Improvement of Pump/Probe-Based LG/LD SAW Spectroscopy System

A novel faint signal processing method based on phase-lock amplification principle is developed to enhance the sensitivity of pump/probe-based laser generated and laser detected surface acoustic waves (LG/LD SAW) spectroscopy system. This novel method involves a “dead zone” filter located before a common phase-lock amplification unit, which wipes off most of the noise stacked on SAW signal. This paper explored the working principle of this novel signal processing method based on the knowledge of the characteristics of the system noise and the signal. The experiment result shows that the detection system’s sensitivity has been dramatically improved by this new signal processing method.