Colloidal optomagnetic dimmer.
We demonstrate a colloidal optomagnetic dimmer based on the interaction between micrometer-sized paramagnetic colloidal spheres and a magnetic film. The colloidal particles undergo Brownian motion, which when exposed to light results in characteristic intensity fluctuations, and we demonstrate that weak magnetic fields that are typically 200 A/m (2.5 G) can be used to control both the average intensity and the intensity fluctuations. The system can be used as a colloidal optical dimmer in microfluidic systems.
School of Physical and Mathematical Sciences, Division of Physics and Applied Physics, Nanyang Technological University, Singapore, Nanyang Crescent, Singapore.
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Helseth
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Wen
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Fischer