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Multi-speckle diffusing wave spectroscopy with a single mode detection scheme

P. Zakharov·F. Cardinaux·F. Scheffold
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Abstract

We present a detection scheme for diffusing wave spectroscopy (DWS) based on a two cell geometry that allows efficient ensemble averaging. This is achieved by putting a fast rotating diffuser in the optical path between laser and sample. We show that the recorded (multi-speckle) correlation echoes provide an ensemble averaged signal that does not require additional time averaging. We find the performance of our experimental scheme comparable or even superior to camera based multi-speckle techniques that rely on direct spatial averaging. Furthermore, combined with traditional two-cell DWS, the full intensity autocorrelation function can be measured with a single experimental setup covering more than 10 decades in correlation time.

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P. Zakharov, F. Cardinaux, F. Scheffold. 2005-09-27. Multi-speckle diffusing wave spectroscopy with a single mode detection scheme. https://doi.org/10.1103/physreve.73.011413

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