Narayanan T, Cheung C, Tong P, Goldburg WI, Wu XL. Measurement of the velocity difference by photon correlation spectroscopy: an improved scheme.
APPLIED OPTICS 1997;
36:7639-7644. [PMID:
18264279 DOI:
10.1364/ao.36.007639]
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Abstract
Homodyne photon correlation spectroscopy is used to measure the velocity difference delta v (l) over varying distance l. Different length scales are probed when the magnification factor M and the width S of a slit in the collecting optics are varied. The measured intensity autocorrelation function is found to be of scaling form for different values of M, provided S is kept at a value below the critical width S (c). A new convenient collecting optics is devised to expand the variable range of l up to 2 decades, over which delta v (l) can be accurately measured. The new scheme is useful for the study of turbulent and other self-similar flows.
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