Multiple optical trapping by means of diffractive optical elements

Dan Cojoc*, Valentina Emiliani, Enrico Ferrari, Radu Malureanu, Stefano Cabrini, Remo Zaccaria Proietti, Enzo Di Fabrizio

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

34 Scopus citations


In this paper we report multiple optical trapping of microscopic dielectric particles using diffractive optical elements implemented on twisted nematic liquid crystal spatial light modulators. The particles are trapped in arrays disposed in plane or in volume and can be moved independently in x-y-z by changing the configuration of the diffractive optical element. We show also multiple trapping using Laguerre-Gaussian and Gaussian beams simultaneously. The orbital angular momentum of the Laguerre-Gaussian beam is transferred to the particle, making it to move on a circular trajectory defined by the intensity pattern specific to this beam. We use sample cells built with two microscope slides separated by 120 μm with a sticky tape. The space between the two slides is filled with 2 μm diameter silica spheres diluted in water (concentration 0.026% wt). We show that optical trapping is also possible in a small glass capillary with a diameter of 100 μm.

Original languageEnglish (US)
Pages (from-to)3910-3915
Number of pages6
JournalJapanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
Issue number6 B
StatePublished - Jun 2004
Externally publishedYes


  • Diffractive optical elements
  • Instrumentation measurement and metrology
  • Optical trapping and manipulation
  • Programmable spatial light modulators

ASJC Scopus subject areas

  • General Engineering
  • General Physics and Astronomy


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