Preparation of Poincaré beams with a same-path polarization/spatial-mode interferometer

Abstract

Abstract. We present a same-path polarization interferometer that uses two spatial light modulators to encode the most general type of Poincaré beam. We demonstrate this design by presenting new results on the encoding of symmetric C-point polarization singularities using spatial modes with high-order topological charges. We also present new results on composite C-points. These are cases where there are multiple C-points in a single beam obtained by combining two modes with composite optical vortices in orthogonal states of polarization. The measurements show good agreement with the simulations.

High-order disclinations in space-variant polarization

“…Before the camera we placed a set of polarization filters to perform imaging polarimetry [8,35]. The images obtained by passage through six polarization filters (horizontal, vertical, diagonal, antidiagonal, right circular and left circular) were used to obtain the Stokes parameters of each imaged point.…”

“…However, the ellipticity of the patterns in the far field is not the same for distinct values of ( ) ℓ ℓ , 1 2 . This is because diffraction reshapes the amplitude of the modes according to the value of the topological charge, yielding ellipticities with distinct radial dependencies [8]. and b=90°.…”

“…The singular point in the dislocation is also known as the C-point [2]. Experimentally, these beams can be produced either by superposition [1,[3][4][5][6][7][8][9]; or by passage through optical elements: spatially variable birefringent plates [10], liquidcrystals with spatially variable birefringence [11][12][13], optical elements with stress birefringence [14], optical fibers [15][16][17], or subwavelength gratings [18]. These beams are increasingly finding applications in classical communications [19] and in quantum information [20].…”

“…The spatial mode with right-circular polarization in equation (1) has two phase vortices of the same absolute value but opposite sign. We have considered previously the case of two phase vortices of distinct absolute value and sign, and imaged them in the far field [8]. This gives rise to a pattern of composite C-points that consists of several disclinations in the same beam.…”

Polarization-based control of spin-orbit vector modes of light in biphoton interference

“…The generation, measurement, and control of vector beams of light, whose transverse spatial and polarization degrees of freedom are nonseparable, have been the subject of a considerable amount of recent attention [1][2][3][4][5][6][7][8][9][10][11][12]. Applications of vector beams in classical optics include polarimetry [13,14], optical communication [15,16], kinematic sensing [17], and optical trapping [18][19][20][21].…”