Share Email Print
cover

Optical Engineering

Selectivity and balance of spatial filtering velocimetry of objective speckles for measuring out-of-plane motion
Author(s): Michael Linde Jakobsen; Hal T. Yura; Steen Grüner Hanson
Format Member Price Non-Member Price
PDF $20.00 $25.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

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.

Paper Details

Date Published: 9 April 2015
PDF: 9 pages
Opt. Eng. 54(4) 047103 doi: 10.1117/1.OE.54.4.047103
Published in: Optical Engineering Volume 54, Issue 4
Show Author Affiliations
Michael Linde Jakobsen, DTU Fotonik (Denmark)
Hal T. Yura, The Aerospace Corp. (United States)
Steen Grüner Hanson, DTU Fotonik (Denmark)


© SPIE. Terms of Use
Back to Top