Wavefront spacing and Gouy phase in presence of primary spherical aberration

We study the Gouy phase of a scalar wavefield that is focused by a lens suffering from primary spherical aberration. It is found that the Gouy phase has different behaviors at the two sides of the intensity maximum. This results in a systematic increase of the successive wavefront spacings around the diffraction focus. Since all lenses have some...

Dynamic Beam Steering from a Subwavelength Slit by Selective Excitation of Guided Modes

Dynamic control of the direction of radiation of the light emanating from a subwavelength slit carved out of a thin metal film is experimentally demonstrated. This is achieved by selective excitation of the individual guided modes in the slit by setting the phase of three coherent laser beams. By changing the voltage across a piezoelement, we...

Manifestation of the Gouy phase in strongly focused, radially polarized beams

The Gouy phase, sometimes called the focal phase anomaly, is the curious effect that in the vicinity of its focus a diffracted field, compared to a non-diffracted, converging spherical wave of the same frequency, undergoes a rapid phase change by an amount of ?. We theoretically investigate the phase behavior and the polarization ellipse of a...

Topological reactions of correlation functions in partially coherent electromagnetic beams

It was recently shown that so-called coherence vortices, singularities of the two-point correlation function, generally occur in partially coherent electromagnetic beams. We study the three-dimensional structure of these singularities and show that in successive cross sections of a beam a rich variety of topological reactions takes place. These...

Correlation singularities in partially coherent electromagnetic beams

We demonstrate that coherence vortices, singularities of the correlation function, generally occur in partially coherent electromagnetic beams. In successive cross sections of Gaussian Schell-model beams, their locus is found to be a closed string. These coherence singularities have implications for both interference experiments and correlation...

Plasmon switching: Observation of dynamic surface plasmon steering by selective mode excitation in a sub-wavelength slit

We report a plasmon steering method that enables us to dynamically control the direction of surface plasmons generated by a two-mode slit in a thin metal film. By varying the phase between different coherent beams that are incident on the slit, individual waveguide modes are excited. Different linear combinations of the two modes lead to...

Coherence converting plasmonic hole arrays

Simulations are presented that demonstrate that the global state of spatial coherence of an optical wavefield can be altered on transmission through an array of subwavelength-sized holes in a metal plate that supports surface plasmons. It is found that the state of coherence of the emergent field strongly depends on the separation between the...

Generalized Gouy phase for focused partially coherent light and its implications for interferometry

The Gouy phase, sometimes called the phase anomaly, is the remarkable effect that in the region of focus a converging wave field undergoes a rapid phase change by an amount of ?, compared to the phase of a plane wave of the same frequency. This phenomenon plays a crucial role in any application where fields are focused, such as optical coherence...

The Gouy phase of Airy beams

The phase behavior of Airy beams is studied, and their Gouy phase is defined. Analytic expressions for the idealized, infinite-energy type beam are derived. They are shown to be excellent approximations for finite-energy beams generated under typical experimental conditions.

Experimental demonstration of an intensity minimum at the focus of a laser beam created by spatial coherence: Application to the optical trapping of dielectric particles

In trying to manipulate the intensity distribution of a focused field, one typically uses amplitude or phase masks. Here we explore an approach, namely, varying the state of spatial coherence of the incident field. We experimentally demonstrate that the focusing of a Bessel-correlated beam produces an intensity minimum at the geometric focus...

Effects of Spatial Coherence on the Angular Distribution of Radiant Intensity Generated by Scattering on a Sphere

In the analysis of light scattering on a sphere it is implicitly assumed that the incident field is spatially fully coherent. However, under usual circumstances the field is partially coherent. We generalize the partial waves expansion method to this situation and examine the influence of the degree of coherence of the incident field on the...

Observation of linear, nonlinear and singular behavior of the Pancharatnam-Berry phase

Creating polarization singularities with an N-pinhole interferometer

Recent studies of singularities in scalar wave fields in Young’s classic experiment are extended to electromagnetic fields diffracted by an N-pinhole interferometer. Linearly polarized fields whose direction of polarization may be different at each pinhole are examined. It is shown that for two pinholes, only surfaces of linear polarization are...

Coherence singularities in the field generated by partially coherent sources

We analyze the coherence singularities that occur in the far field that is generated by a broad class of partially coherent sources. It is shown that for rotationally symmetric planar quasihomogeneous sources the coherence singularities form a two-dimensional surface in a reduced three-dimensional space. We illustrate our results by studying the...

Plasmon-assisted two-slit transmission: Young's experiment revisited

Connection between phase singularities and the radiation pattern of a slit in a metal plate

Light transmission through a subwavelength slit: Waveguiding and optical vortices

Reflection-induced spectral changes of the pulsed radiation emitted by a point source