Transfer of orbital angular momentum from a super-continuum, white-light beam

Transfer of orbital angular momentum from a super-continuum, white-light beam.

Beams with helical phasefronts described by exp(ilphi) carry an orbital angular momentum equivalent to lh per photon. Using diffractive optics this helical phase structure can be applied to every spectral component of the beam such that a spatially coherent white-light beam can carry orbital angular momentum without any chromatic distortion. This achromatic property can be hard to achieve in sp...

Observation of the rotational Doppler shift of a white-light, orbital-angular-momentum- carrying beam backscattered from a rotating body

We observe the rotational Doppler shift of an orbital angular momentum (OAM)-carrying white-light beam after it is backscattered from a rotating object. Unlike the well known linear shift, this rotational shift is independent of the optical frequency, and hence each spectral component of the scattered light is shifted by the same value. Consequently, even a white-light source can give rise to a...

Generation of a White-Light Super Continuum

Orbital angular momentum and nonparaxial light beams

The simple relationship between total angular momentum and energy and the seemingly natural separation of the angular momentum into spin and orbital components in the paraxial approximation, are investigated for a general nonparaxial form of monochromatic beam with near cylindrical symmetry.

Orbital Angular Momentum Density of a Hollow Vortex Gaussian Beam

Here the hollow vortex Gaussian beam is described by the exact solution of the Maxwell equations. By means of the method of the vectorial angular spectrum, analytical expressions of the electromagnetic fields of a hollow vortex Gaussian beam propagating in free space are derived. By using the electromagnetic fields of a hollow vortex Gaussian beam beyond the paraxial approximation, one can calc...