Possibilities of using inhomogeneity in light energy distribution for estimating the degree of coherence of superposing waves

Abstract

The paper presents a new method for determining the degree of coherence of superposing plane linearly polarized waves converging at the angle of 90°. The spatial modulation of polarization, which causes the spatial modulation of the averaged values of the Poynting vector, presets the modulation of the volume energy density. Such an inhomogeneous optical field can affect nano-sized particles randomly caught in this field. The paper shows that the maximum velocity of "trapping" the particles into the regions of maximum averaged values of the Poynting vector determines the degree of coherence of interacting waves.

The Use of New Approaches to Estimating the Coherence Properties of Mutually Orthogonal Beams

“…The modulation of polariza- The superposition of plane waves of equal amplitudes linearly polarized at the incidence plane, with interference angle of 90°. Periodical spatial modulation of polarization [21,22,30] takes place in the plane of incidence.…”

“…m ) are the values of the dielectric permittivity of a gold particle (a surrounding me-dium) correspondingly. Taking into consideration that for golden particles in water n = 0.32 + 2.65i [30], the real and imaginary parts of the dielectric permittivity are calculated using the Kramers-Kronig relation. As it was obtained in [31]…”

Use of motion peculiarities of test particles for estimating degree of coherence of optical fields

“…Using the methods suggested in the studies [18,22,25], one can illustrate the motion of particles of various sizes in the optical fields formed by superpositions of coherent or partially coherent beams. For receiving a more complete and vivid picture of the particle motion, it is also necessary to take into consideration a set of forces resulted from the liquid in which the particles are maintained in suspension.…”

“…1). These waves would determine the averaged electric (magnetic) energy density and the normal propagation direction of the resulting wave [18,25]. [19][20][21] takes place in the plane of incidence.…”

A new method for estimating the degree of coherence of mutually orthogonal linearly polarized interacting waves

“…Let us consider the superposition of two plane waves W1, W2 of equal amplitudes polarized in the plane of incidence (Fig. 1), and determine the averaged value of the electric (magnetic) energy density and the direction of the resulting wave propagation 13,14 . …”