The design and operation of a microprocessor-based system used to record and analyze experimental data in a quantum physics laboratory are described. The current second-generation system, developed at the Technical University of Poznán, Poland, is based on an IBM PC–compatible computer system and a single-board front-end processor, and it samples up to 128 channels at 90 kHz. Once the data have been collected, the single-board computer transfers the data to the computer system for mathematical analysis of either an auto- or a cross-correlation function of photons in scattered light.

The paper includes a mathematical description of the auto-correlation function; a fairly detailed explanation of the implementation of the hardware components of the system; an overview of the system software with emphasis on the time-critical portions of the algorithm; and a description of experimental techniques that might use the system. Although the specific application discussed in the paper seems to have a fairly narrow audience, the underlying approach to developing intelligent instrumentation for mid-range data sampling rates using relatively inexpensive components could be of general interest to physical scientists working in experimental laboratories.