Novel, adaptive, scanning laser vibrometer for measurements on rotating propellers in water

This Small Business Innovation Research Phase I project will investigate a novel alternative to the laser Doppler vibrometer for measurements on rotating propellors in water. Specifically, we will investigate a vibrometer based on photo-emf detection, in conjunction with conventional rotational tracking. The vibrometer incorporates a reference-beam interferometer to provide optical signals to the photo-emf detector. We believe that this type of vibrometer is significantly less susceptible to undesirable signals and added noise that compromise the performance of conventional Doppler vibrometers. We will describe preliminary experiments which support this point of view. During the program we will characterize and optimize our interferometer, leading to a direct side-by-side comparison with a Doppler instrument. At the conclusion of the Phase I effort we plan to demonstrate the feasibility and advantages of our approach, which should result in a robust, low-cost scanning device which can interrogate diffuse surfaces with minimum impact from the beam rotation process.