Formation of polarized beams in chains of dielectric spheres and cylinders

Abstract

Using numerical modeling, it is shown that chains of dielectric spheres and cylinders act as polarizers. The mechanism is based on gradual filtering of periodically focused modes with a certain polarization propagating with minimal losses due to Brewster angles conditions, whereas orthogonally polarized modes are strongly attenuated. It is shown that chains of cylinders filter linearly polarized beams, whereas chains of spheres filter radially polarized beams. In the geometrical optics limit, we show that in a range of sphere refractive indices 1.68-1.80 a degree of radial polarization in excess of 0.9 can be obtained in 10-sphere-long chains.

Spectrally resolved resonant propulsion of dielectric microspheres

“…Besides coupling between WGMs, microspherical arrays support a different type of optical mode termed photonic "nanojet-induced" [66][67][68] or "periodically focused" [69] modes. Due to these modes, the chains of spheres can operate as polarization filters [70], lowloss waveguides with focusing capability [66][67][68] and laser surgical devices [71][72][73][74]. Arrays of microspheres can also be used in super-resolution imaging applications [75][76][77].…”

Biological super-resolution imaging by using novel microsphere-embedded coverslips

“…However, for micronscale spheres, the super-resolution strength can be additionally enhanced due to "photonic nanojet" properties of microspheres [1,5]. Focusing properties of microspheres, such as "photonic nanojets" [6] and "periodically focused modes" [1,7,8] have motivated their application in light focusing and imaging devices [7][8][9][10][11][12].…”

Super-resolution imaging by arrays of high-index spheres embedded in transparent matrices

“…Fundamentally, a connection between the super-resolution strength of the microspheres and their ability to focus light into sub-diffraction limited dimensions has also been noted [1]. These tightly focused beams have been termed "photonicnanojets" [8][9][10] and corresponding "nanojet-induced modes" [11][12][13][14][15][16][17][18][19] have experimentally been observed in single spheres and chains of spheres, respectively.…”