Hartmann wave front sensor studies of dynamic organized structure in flowfields

Abstract

The results of an investigation of a one-dimensional Shack-Hartmann wave front sensor are presented for measurement of an optical wave front after passage through a round low-speed jet. The sensor has a linescan rate of 2.2 kHz that resolves the passing vortical features of the developing jet flow. After a brief summary of the principles of Hartmann sensing, results of an experimental determination of the sensitivity limits of our particular wave front sensor are presented. Noise sources in Hartmann sensing are then reviewed, and results of a simulation are presented to show the influence of noise on the resolution limits of the Hartmann sensor. The relevance of the simulation results to the design of a 2.2-kHz, multiview, tomographic system based on Hartmann sensing is also discussed.