Experimental measurements are reported of the rotation rates superpositions higher-order Bessel beams. Digitally generated phase masks two annular rings, were imprinted on a spatial light modulator and used to obtain beams same order but opposite topological charge. Such superposition field carries average zero orbital angular momentum, yet exhibits in intensity pattern: resultant rotates at constant rate about optical axis as it propagates. The fields measured for different orders various...

We introduce an effective optical system to produce beams with arbitrary, inhomogeneous polarization states. Using our system, we are capable of generating vector discretionarily chosen transverse complex fields in a straightforward way. generate several different instances well-known and the less common spirally polarized beams, as well full Poincaré beam. visually show continual transition between azimuthally radially via collection beams. experimentally determine states generated...

We present the experimental generation and characterization of each one four fundamental families Helmholtz-Gauss beams: cosine-Gauss beams, stationary helical Mathieu-Gauss traveling parabolic-Gauss Bessel-Gauss beams. Both transverse intensity profile power spectrum that beams exhibits upon propagation is observed compared to theoretical model with good quantitative agreement. Emphasis made on fact HzG complete orthogonal, thus relevance.

We demonstrate that nondiffracting beams can be generated with an arbitrary transverse shape. In particular, we show the azimuthal complex modulation of angular spectra Helmholtz-Gauss wave fields constitutes a degree freedom sufficient to tailor intensity pattern choice.

Propagation invariant light fields such as Bessel beams are of interest in a variety current areas micromanipulation atoms and mesoscopic particles, laser plasmas, the study optical angular momentum. Considering superposition conical waves, we discuss how coherence properties play key role their formation. As an example, show that can be created from temporally incoherent broadband sources including halogen bulb. By using supercontinuum source elucidate beam behaves function bandwidth incident field.

Phase-only spatial light modulators are now ubiquitous tools in modern optics laboratories, and often used to generate so-called structured light. In this work we outline the use of a phase-only modulator achieve full complex amplitude modulation light, i.e., phase. We theoretical concept, then illustrate its with example laser beam shaping Gaussian beams into flat-top beams. quantify performance approach for creation such fields, compare results conventional lossless approaches generation.

We present a simple experimental procedure for producing computer-generated hologram of good quality. As an example, the transverse intensity and phase structure nondiffracting beams is investigated.

We present the use of optical fibers to form a counter-propagating trap as means manipulating both solid and liquid aerosols. explore single multimode achieve trapping various particles in air, properties different fiber types compare observed trends those predicted by theory. Using fibers, we are able hold suspended for extended periods time precisely manipulate them over distances several hundred microns. discuss difficulties advantages each configuration conclude with demonstration that...

The vortex emergence process as an integer order Bessel field progresses continuously onto the contiguous higher is studied in detail. We assess progressive migration of phase singularities and explain predicted increase fractional orbital angular momentum content beam terms this gradual process.

A new experimental setup is demonstrated to produce high-order Bessel beams. It based on the field decomposition of beam into its even and odd components. The implementation performed over spectral components with a Mach-Zehnder interferometer that synthesizes desired beam. main advantage our required annular transmittances have only discrete phase changes pi radians instead continuous change phase.

Degenerate four-wave mixing is demonstrated using an artificial Kerr medium and evidenced by directly observing the phase conjugation of a vortex signal beam. The nonlinear susceptibility produced refractive index grating created in suspension dielectric microscopic particles optically confined intensity distribution two interfering laser beams.

Optical trapping forces depend on the difference between trap wavelength and extinction resonances of trapped particles. This leads to a wavelength-dependent force, which should allow for optimization optical tweezers systems, simply by choosing best given application. Here we present an tweezer system with tunability, study resonance effects. With this system, stiffness is measured single particles that exhibit either or multiple resonances. We include discussions effects, such as changes...

We present a novel optical method, to our knowledge, measure the refractive index of liquids by means images produced an optofluidic lens. In addition we propose new method make lenses.

We report the use of light from a thermal source for optical guiding microscopic particles. demonstrate successful dielectric spheres using high-pressure gas lamp shaped into an ad hoc Bessel wavefield with enhanced transverse gradient and long focal depth. The broadband is spectrally characterized potential applications our observations are outlined.

We observe the transfer of orbital angular momentum to trapped particles in azimuthally asymmetric transverse intensity distribution a helical Mathieu beam. The average rotation rate, instantaneous displacement and terminal velocity are measured experimentally. dependence these parameters is found be good agreement with variation optical gradient force, OAM from wavefield Stokes drag force.

We present a generalization of the known spirally polarized beams (SPBs) which we will call generalized (GSPBs). characterize in detail both theoretically and experimentally streamline morphologies GSPBs their transformation by arbitrary polarization optical systems described complex Jones matrices. find that description passage through system is equivalent to stability theory autonomous ordinary differential equations. While streamlines GSPB exhibit spiral geometry, output field may...

We investigate theoretically and experimentally the propagation characteristics of Helical Hermite-Gauss beams corresponding to helical Ince-Gauss in limit infinite ellipticity. Particular attention is paid transverse irradiance structure, orbital angular momentum density, vortex distribution.

Laguerre-Gaussian (LG) beams have been extensively studied due to their unique structure, characterized by a phase singularity at the center of beam. Common methods for generating such include use diffractive optical elements and spatial light modulators, which although offering excellent versatility, suffers from several drawbacks, including in many cases low power damage threshold as well complexity expense. This paper presents simple, cost method generation high-fidelity LG using rapid...

This special issue of Optics & Photonics News (OPN) highlights the most exciting peer-reviewed optics research to have emerged over past 12 months. The areas covered in 2011 include bio-optics, detection, diffraction, imaging, interferometry, nonlinear optics, photonic structures, plasmonics, quantum terahertz technology, transformation ultrafast and 3-D recording display.

The ability to confine flows and focus particle streams has become an integral component of the design microfluidic systems for analysis a wide range samples. Presented here is implementation 3D nozzle capable both focusing particles as well dynamically positioning those in selected flow lamina within downstream channel. Through independent adjustment three sheath inlet flows, controlled size focused stream 6, 10, 15 μm polystyrene microparticles. Additional allowed position specific area...

A beam shaping method based on the superposition and <i>unwinding</i> of vortex beams is proposed. This allows for continuous tuning orbital angular momentum content longitudinal intensity distribution beam. We provide with a closed expression general find its relation to functional parameters beams. compare our theoretical predictions experimental results excellent fidelity.

We present a method to calculate the 2-dimensional complex angular spectrum required produce Helmholtz- Gauss (HzG) beam with an arbitrary intensity profile. Using iterative Fourier transform algorithm, we find numerical solutions for several instances of spectra and reproduce corresponding beams by encoding resulting on spatial light modulator. verify experimental results compare them computer model their propagation excellent agreement. quantitatively asses fidelity produced expected...