Holographic optical tweezers were used to show the interaction between a strongly focused laser beam and magnetic nanoparticles in ferrofluid. When the light intensity was high enough, magnetic nanoparticles were removed from the beam center and formed a dark ring. The same behavior was observed when focusing vortex or Bessel beams. The interactions between two or more separated rings of magnetic nanoparticles created by independent optical traps were also observed.
© 2013 Optical Society of America
Atomic and Molecular Physics
Original Manuscript: June 11, 2013
Revised Manuscript: August 22, 2013
Manuscript Accepted: August 30, 2013
Published: September 30, 2013
Jan Masajada, Marcin Bacia, and Sławomir Drobczyński, "Cluster formation in ferrofluids induced by holographic optical tweezers," Opt. Lett. 38, 3910-3913 (2013)