Generation of doughnut laser beams by use of a liquid-crystal cell with a conversion efficiency near 100%

Abstract

We present a novel technique for producing a doughnut laser beam by use of a liquid-crystal cell. It is demonstrated that the liquid-crystal cell exhibits an efficiency in energy conversion near 100%. One of the main advantages of this method is its capability of dynamic switching between a Gaussian mode and a doughnut mode of different topological charges. The liquid-crystal cell is also dynamically tunable over the visible and near-infrared wavelength range. These advantages make the device appealing for laser trapping methods used in single-molecule biomechanics and for optical guiding of cold atoms.

Focal patterns of higher order hyperbolic-cosine-Gaussian beam with one optical vortex

“…In practice, this condition is very common, especially in life science (Gao et al 2004). Therefore, construction of dark focal spot is very important and attracts many researchers (Arlt and Padgett 2000;Gbur and Visser 2003;Ganic et al 2002). From evolution process in Fig.…”

Single‐Molecule Detection and Manipulation in Nanotechnology and Biology

“…These CGH patterns acted as a diffractive optical element (DOE) in the beam path to produce the desired mode, which could then be selected and used. This same dislocation can be created by helically shifting the wavefront [114]. When focused down by a high-NA objective, the beam maintains its dark core (Fig.…”

Calculating the torque of the optical vortex tweezer to the ellipsoidal micro-particles

“…We select the TEM 01 n Doughnut beam as the incident light [16], whose radial intensity distribution can be written as:…”