Correlation optical velocimetry with a compact disk pickup

The compact disk pickup is a consumer electronics component that can be purchased for a low price owing to the great number of units produced every year. A typical three-beam head contains, enclosed in a tiny case, a quite complete sample of what can be found in an optoelectronics laboratory: a coherent source, a grating, a polarizing beam splitter, a fourth-wave plate, solid-state detectors, and much more. Exploiting the unique features of such a device for scientific aims is intriguing from many points of view. We present a straightforward application of a compact disk pickup to optical correlation velocimetry and show how a rather complicated discrete setup can be replaced successfully by this highly integrated component.