A controllable energy method, which considers the undersampling issue of transfer function and valid spectral a source signal, is proposed to implement angular spectrum diffraction calculation in near far fields. The method provides an optimized frequency boundary fCE within it always keeps be diffracted. significantly reduces number samples while having same accuracy as previous methods, imply...

We implement an interferometric method using two angular slits to measure the orbital-angular-momentum (OAM) mode spectrum of a field with partial angular coherence. As the angular separation of the slits changes, an interference pattern for a particular OAM mode is obtained. The visibility of this interference pattern as a function of angular separation is equivalent to the angular correlation...

Gaussianity and statistical isotropy of the universe are modern cosmology's minimal set of hypotheses. In this work we introduce a new statistical test to detect observational deviations from this minimal set. By de ning the temperature correlation function over the whole celestial sphere, we are able to independently quantify both angular and planar dependence (modulations) of the CMB temperat...

We will present an interactive computer-generated hologram technique using spherical angular spectrum. The spherical angular spectrum consists of the frequency spectrum of the object wave in all-around directions. The spherical angular spectrum is computed by a formula of the Fourier coefficients of point light source. Given a spherical angular spectrum, one can generate a planar hologram at a ...

The notion of a spherical angular spectrum leads to the decomposition of the field amplitude on a spherical emitter into a sum of spherical waves that converge onto the Fourier sphere of the emitter. Unlike the usual angular spectrum, the spherical angular spectrum is propagated as the field amplitude, in a way that can be expressed by a fractional order Fourier transform.

The angular spectrum approach is evaluated for the simulation of focused ultrasound fields produced by large thermal therapy arrays. For an input pressure or normal particle velocity distribution in a plane, the angular spectrum approach rapidly computes the output pressure field in a three dimensional volume. To determine the optimal combination of simulation parameters for angular spectrum ca...

We introduce the concept of quasi-intrinsic angular momentum to denote fields for which the mean value of the angular momentum is unaltered by a lateral shift of the rotation axis but the spectrum changes. This property is exemplified by the orbital angular momentum of a beam of light about its propagation direction. We propose an interferometric experiment to measure efficiently the exact angu...