Polarization singularities of focused, radially polarized fields

Abstract

Abstract:The state of polarization of strongly focused, radially polarized electromagnetic fields is examined. It is found that several types of polarization singularities exist. Their relationship is investigated, and it is demonstrated that on smoothly varying a system parameter, such as the aperture angle of the lens, different polarization singularities can annihilate each other. For example, the evolution of a lemon into a monstar and its subsequent annihilation with a star is studied. Also, the quite rare collision of a C-line and an L -line, resulting in a V -point, is observed.

Conical refraction: fundamentals and applications

“…This behavior has been also observed in the focusing of radially polarized beams and explored in detail in Refs. [136,137] To test the validity of the obtained theoretical results, we have performed the corresponding experimental measurements. Fig.…”

Composite spectral Stokes singularities in coherent and incoherent superpositions of partially coherent nonparaxial vortex beams

“…In analogy to Refs. [7,19], if we suitably change the definition of the spectral Stokes parameters, the spectral Stokes singularities can be extended from the paraxial regime to the nonparaxial one.…”

“…The vector singularities, including U (unpolarized) lines, P (completely polarized) points of incoherently combined beams in the paraxial approximation were analyzed by Felde et al [5] and Chernyshov et al [6]. Schoonover and Visser examined the state of polarization of strongly focused radially polarized fields and observed the collision of a C-and L-lines, which results in a V-point [7]. A uniform description of polarization singularities in terms of the phase singularities of complex Stokes scalar fields was proposed by Freund et al [8].…”

Stability of polarization singularities in disordered photonic crystal waveguides

“…With the vector nature of electromagnetic fields, optics is an obvious place for the study and application of polarization singularities, and they can be found in systems ranging from tightly focused beams [2] to speckle fields [3,4] to photonic crystals [5] and others [6][7][8]. For example, at circular polarization points, the orientation of the polarization ellipse is singular, whereas along contours of linear polarization the handedness is singular.…”