Vector optical fields with bipolar symmetry of linear polarization

Abstract

We focus on a new kind of vector optical field with bipolar symmetry of linear polarization instead of cylindrical and elliptical symmetries, enriching members of family of vector optical fields. We design theoretically and generate experimentally the demanded vector optical fields and then explore some novel tightly focusing properties. The geometric configurations of states of polarization provide additional degrees of freedom assisting in engineering the field distribution at the focus to the specific applications such as lithography, optical trapping, and material processing.

Dynamic plasmonic beam shaping by vector beams with arbitrary locally linear polarization states

“…17 While an azimuthally polarized (AP) beam is unable to excite SPPs due to the polarization mismatch. 13 In recent years, apart from the well-known RP and AP beams, a lot of other vector beams with various space-variant state of polarization (SOP) have been reported, [18][19][20][21][22][23][24][25] for instance, vector beams with cylindrical, [18][19][20] elliptical, 21 and bipolar symmetries 22 of linear polarization. The geometric configuration of linear polarizations as an additional degree of freedom should be considered in terms of SPPs manipulation, and consequently, produces more novel phenomena with great potentials to new applications.…”

“…When it comes to the vector beams with higher order axial symmetry, we found multifoci of SPPs with the same size and uniform intensity can be obtained, the number of which is controllable depending on the polarization order n. In addition, the mechanisms and reasons for that excellent performance are also explained. Most importantly, our analytical model can be applied to investigate the behaviors of vector beams with arbitrary locally liner SOP in terms of SPPs excitation, such as vector beams with elliptical symmetry, 21 bipolar symmetry, 22 and parabolic symmetry, 25 yielding more novel phenomena with great potentials to new applications. …”

Parabolic-symmetry vector optical fields and their tightly focusing properties

“…An elliptical-symmetry vector field has also been investigated [21], for which the local linear polarizations are always along the tangential direction of concentric ellipses. Very recently, we reported other two kinds of vector fields: with linear polarization distributions modeling to field lines [22] and with bipolar symmetry of linear polarization [23].…”

“…1 is very similar to those used in Refs. [14,18,19,23]. This approach includes four key steps: (i) an input linearly polarized laser field is divided into two equiamplitude parts, which are easily achieved by use of a sine-cosine grating displayed on a spatial light modulator (SLM) in the input plane of the 4f system; (ii) the two parts must carry the space-variant phase δ(x,y); (iii) the two parts must pass through different optical paths, making the two * htwang@nankai.edu.cn; htwang@nju.edu.cn parts become orthogonally right-and left-handed circularly polarized by a pair of 1/4-wave plates behind a spatial filter (SF) in the Fourier plane of the 4f system; and (iv) the two parts are combined by the Ronchi phase grating (G) in the output plane of the 4f system.…”

“…Similarly to the generation of the cylindrical vector fields [14,18,19], in particular, of the bipolar vector fields [23], we set the space-variant phase δ as…”