Abstract
This paper describes an optical spatial filtering velocimetry technique that converts an expanding or contracting speckle pattern into a photocurrent. This photocurrent will have a quasi-sinusoidal dependency on this specific speckle motion. The spatial filter consists of a series of concentric rings. Each ring divides the incoming light into two radial-wise, almost even contributions and directs them by refraction toward two half-rings of photodetectors. The corresponding two photocurrents are balanced and provide a differential photocurrent. In this paper the optical spatial filtering velocimetry technique is used to demonstrate real-time measurements of speckle dynamics due to out-of-plane motion.
Original language | English |
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Journal | Applied Optics |
Volume | 55 |
Issue number | 14 |
Pages (from-to) | 3858-3865 |
ISSN | 1559-128X |
DOIs | |
Publication status | Published - 2016 |