Optical Trapping in a Dark Focus

Path integrals and nonlinear optical tweezers

“…The yellow curves are Lorentzian fits, which reveal a dependence approximately of the form f c ∝ √ D √ a. This dependence could be used, for instance, to calibrate purely cubic forces, such as the ones generated in bottle beams optical traps [18]. The parameters used in this simulation were the same as the ones used for Fig.…”

“…Trapping the particle with beams that have complex intensity profiles is also an interesting possibility, and various optical potentials have been studied in the literature, such as the double-well landscape [15,16], structured light beams with pattern revivals [17], bottle beams [18], frozen waves [19] and cylindrical vector beams [20]. The optical potentials generated by these structured light optical traps are generally not harmonic, and the Brownian particle is subject to nonlinear force terms.…”

Singular Warped Beams Controlled by Tangent Phase Modulation

“…However, according to [30] with a similar configuration they can observe trapping of 2 µm particles using a 7 µm camera pixel size. For particles that have a refractive index lower than the surrounding medium, the dark spots can also be converted to trapping regions [31]. In this case by observing Figure 6f,g,h, there were at least six singular dark points that were rotating around the center while the beam passed through the focal point.…”

Precise measurement of trapping and manipulation properties of focused fractional vortex beams

“…Optical tweezers, known as a single-beam gradient force trap, have raised lots of interest since Ashkin et al developed them in 1986, 1 and they have been applied in many fields, such as bioscience, [2][3][4] nano fabrication, 5,6 and enatioselection of nanoparticles. [7][8][9][10] Considering their excellent performances in manipulating particles ranging from tens of nanometers to tens of micrometers, it's convenient to apply them to explore the exotic trapping or manipulation characteristics of structured light fields, to mention but a few, such as Laguerre-Gaussian beams, [11][12][13][14][15][16] Bessel beams, 17,18 Airy beams, 19,20 partially coherent beams, 21,22 cylindrical vector beams, 23,24 and perfect vortex beams. 25,26 Recently, Otte and Denz provided a timely overview on recent advances in advanced optical trapping and future perspectives in optical manipulation with structured light fields.…”