Journal article
Selectivity and balance of spatial filtering velocimetry of objective speckles for measuring out-of-plane motion
We probe the dynamics of objective laser speckles as the axial distance between the object and the observation plane changes. With the purpose of measuring out-of-plane motion in real time, we apply optical spatial filtering velocimetry to the speckle dynamics. To achieve this, a rotationally symmetric spatial filter is designed.
The spatial filter converts the speckle dynamics into a photocurrent with a quasi-sinusoidal response to the out-of-plane motion. Our contribution presents the technology, discusses the selectivity of the spatial filter and proposes two solutions to balance phase-stepped photocurrents. Specifically, we discuss how the selectivity of the spatial filter with regard to radial speckle motion is influenced by a concurrent in-plane speckle motion.
The spatial filter is emulated with a CCD camera and is tested on speckle acquisitions obtained from a controlled setup. Experiments with the emulated filters illustrate the performance and potential applications of the technology.
Language: | English |
---|---|
Year: | 2015 |
Pages: | 047103 |
ISSN: | 15602303 and 00913286 |
Types: | Journal article |
DOI: | 10.1117/1.OE.54.4.047103 |
ORCIDs: | Jakobsen, Michael Linde and Hanson, Steen Grüner |