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Axial position detection for optical tweezers based on Moiré Deflectometry

Khorshad, A. A ; Sharif University of Technology | 2019

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  1. Type of Document: Article
  2. DOI: 10.1016/j.optcom.2019.03.065
  3. Publisher: Elsevier B.V , 2019
  4. Abstract:
  5. Optical tweezers are indispensable instruments for applying and measuring Pico-Newton range forces. The magnitude of the exerted force is determined by measuring the displacement of the trapped bead from the center of the trap. Recently, we developed a new detection system for optical tweezers based on Moiré Deflectometry (MD). In this work, we show, both theoretically and experimentally, that the introduced method can be used for detection in the axial direction, as well, with a significantly larger sensitivity compared to the commonly used QPD method. As an example, for a 2.17μm polystyrene bead this method could provide a sensitivity 285% larger than that of the QPD method. © 2019 Elsevier B.V
  6. Keywords:
  7. Detection ; Diffraction theory ; Moiré techniques ; Optical tweezers or optical manipulation ; Error detection ; Laser theory ; Photodiodes ; Axial direction ; Axial positions ; Deflectometry ; Detection system ; Laser trapping ; Optical manipulation ; Polystyrene beads ; Optical tweezers
  8. Source: Optics Communications ; Volume 446 , 2019 , Pages 33-38 ; 00304018 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S0030401819302779#!