Adaptive optics in an optical trapping system for enhanced lateral trap stiffness at depth
Müllenbroich, Caroline and McAlinden, Niall and Wright, Amanda (2013) Adaptive optics in an optical trapping system for enhanced lateral trap stiffness at depth. Journal of Optics, 15 (7). 075305. ISSN 0972-8821 (https://doi.org/10.1088/2040-8978/15/7/075305)
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Abstract
In optical trapping systems the trap stiffness, or spring constant, deteriorates dramatically with trap depth due to optical aberrations and system misalignment. This can severely hamper studies that employ optical tweezers to make accurate quantitative measurements. Here, a deformable membrane mirror is used, in conjunction with a random search algorithm, to correct for these aberrations by optimizing on a merit factor that is directly proportional to the trap stiffness. Previous studies have sought to address this issue but none have used a merit factor that is directly proportional to the trap stiffness. We demonstrate that the lateral trap stiffness, measured with and without aberration correction at increasing depths, improves throughout the trapping range of a conventional trap and allows us to extend the maximum depth at which we can trap from 136 to 166 μm. At a depth of 131 μm, trap stiffness improved by factors of 4.37 and 3.31 for the x- and y-axes respectively. The aberration correction resulted in deformable membrane mirror shapes where a single shape could be applied throughout a wide range of trap depths, showing significant improvement, and had the added benefit of making the lateral trapping forces more uniform in x and y.
ORCID iDs
Müllenbroich, Caroline, McAlinden, Niall ORCID: https://orcid.org/0000-0002-0369-8788 and Wright, Amanda;-
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Item type: Article ID code: 44287 Dates: DateEvent2 July 2013PublishedSubjects: Science > Physics Department: Faculty of Science > Physics > Institute of Photonics Depositing user: Pure Administrator Date deposited: 04 Jul 2013 10:11 Last modified: 02 Sep 2024 00:43 Related URLs: URI: https://strathprints.strath.ac.uk/id/eprint/44287