H. I. Sztul

The Poynting vector and angular momentum of Airy beams

We analyze and describe the evolution of the Poynting vector and angular momentum of the Airy beam as it propagates through space. A numerical approach is used to show the Poynting vector follows the tangent line of the direction of propagation. A similar approach is used to show that while the total angular momentum of the Airy beam is zero, the angular momentum of the main intensity peak and the Airy “tail” are non-zero.

Double-slit interference with Laguerre-Gaussian beams

The interference of Laguerre-Gaussian beams carrying orbital angular momentum was demonstrated in Youngs double-slit geometry. Double-slit interference is shown to be affected by the azimuthal phase dependence of a Laguerre-Gaussian beam. This interference provides new insight into the helical phase structure of the Laguerre-Gaussian beam and has potential applications for measuring the orbital angular momentum of an arbitrary wavefront.

Ultrashort Laguerre-Gaussian pulses with angular and group velocity dispersion compensation

Coherent optical vortices are generated from ultrashort 6.4 fs pulses. Our results demonstrate angular dispersion compensation of ultrashort 6.4 fs Laguerre-Gaussian (LG) pulses as well as what is believed to be the first direct autocorrelation measurement of 80 fs LG amplified pulses. A reflective-mirror-based 4f-compressor is proposed to compensate the angular and group velocity dispersion of the ultrashort LG pulses.

Stokes polarimetry of a hybrid vector beam from a spun elliptical core optical fiber

A hybrid vector polarization beam with a donut like intensity profile is produced at the output of a spun elliptical core optical fiber by coupling an off-axis TEM00 laser mode at the input. The local polarization states of the fiber output are analyzed using Stokes polarimetry. The Stokes parameters are measured using a combination of quarter wave plate and linear polarizer. A detailed polarization map of the hybrid beams cylindrically symmetric and varying elliptical polarization state around the beam axis is also numerically discussed.

Cylindrical vector beam generation from spun fiber

Recently there has been considerable interest in the generation of cylindrical vector beams for numerous possible applications in nano-biophotonics, optical imaging, the laser processing of materials and the generation of single photon sources among others. Cylindrical vector optical vortex beams are shown by propagating a fundamental laser mode through a spun ber. The polarization state of the output from the ber is characterized and the the process of this mode conversion will be discussed.

Propagation of a hybrid vector polarization beam in a uniaxial crystal

The propagation of a hybrid vector polarization beam is experimentally investigated in an uniaxial birefringent quartz crystal. The hybrid beam can be expressed as a superposition of two orthogonal linearly polarized Laguerre-Gaussian modes of opposite topological charge. When propagating through the crystal, the beam decomposes into the two orthogonal components traveling along the ordinary and extraordinary rays. Investigation of the beams phase and polarization structure after propagation through the crystal shows a fork fringe pattern arising from interference between the orthogonally polarized components of opposite topological charge.

Geometric phase associated with transformations of cylindrical vector beams

We present a geometric phase arising from transformations along the surface of a Poincare sphere representation for cylindrical vector beams. Cylindrical vector beams are expressed as the superposition of orthogonal circular polarized Laguerre-Gaussian modes of opposite topological charge. Two spheres are described where the poles of each sphere are circular polarized Laguerre-Gaussian modes, and points along the equator are cylindrical vector beams. A closed loop transformation on the spheres surface is carried out using combinations of wave plates and cylindrical lens mode converters, and an acquired geometric phase is experimentally measured interferometrically.

Velocity of optical Airy beams

Optical Airy beams have gained significant attention due to their parabolic trajectory, accelerating and nondiffractive behavior. The phase velocity of the Airy solution to the paraxial wave equation is described showing a unique behavior. The velocity is shown to vary spatially and in magnitude as the beam propagates through vacuum along its curved trajectory.

Momentum of optical Airy beams

We analyze and describe the evolution of the Poynting vector and angular momentum of the Airy beam as it propagates through space. A numerical approach is used to show the Poynting vector follows the tangent line of the direction of propagation. A similar approach is used to show that while the total angular momentum of the Airy beam is zero, the angular momentum of the main intensity peak and the Airy tail are non-zero. These beams have promise for applications in imaging and spectroscopy where a sample might interact with a changing momentum and spatially varying angular momentum.

The Poynting Vector and Angular Momentum of Airy Beams

We analyze and describe the evolution of the Poynting vector and angular momentum of the optical Airy beam. A numerical approach is used to show these values explain the acceleration of this beam.