Investigation On Self-bending Beams’ Property And Pixilated- Micropolarizer-array Camera’s Application In Light’s Phase Measurement

In recent years, self-bending beams are becoming a hot research topic of optic science. Such beams have special traits like curved trajectory and self-healing during their propagation, which are regarded as great candidates to be applied in fields of nonlinear optics, optical tweezers, signal transmission and the like. A lot of interesting and meaningful work is also booming, which is associated with the generation, diffraction features and potential applications of self-bending beams. However, as there is no efficient and convenient measurement tool, recent studies about self-bending beams are focused on numerical modeling and experimental measurement of their intensity patterns. There barely exist useful experimental research about phase distribution of self-bending beams, let alone the role of evolving phases in beam’s structure during its propagation. In consideration of mentioned situations above, we produced a CCD camera attached with a 640x320 pixilated micropolarizer array (PMA) based on former work our group did before, and utilize it in interference path with polarization phase-shifting method to measure the phase information of self-bending beams in real time.Besides that, we combined the numerical modeling and experimental method to study the intensity patterns and phase structures of self-bending beams, and the influence of the evolving phases in the spacial structures during beams’propagation. Based on these aspects, we carried out relevant researches mainly in the sections below:(1) We determine the processing parameters by theoretical analysis and reference paper. The processing effects of PMA are evaluated through the observation by optical microscope and scanning electron microscope (SEM). The extinction ratios and maximum transimission were measured in the polarization detection system.(2) According to the restraint equations of the modulated phases to generate the generalized polygon beams (GPA), we obtained the mathematical form of GPA’s modulated phases with arbitary integer sides by polar-coordinate analysis. We use Matlab to operate the numerical modulation of diffraction of beams imposed with such modulated phases, a consistent result is achieved in the diffraction experiment with a spatial light modulator, which is used to modulate the phases of incident beam.(3) We used the PMA camera to measure the evolving phases of GPA, the experimental results we got matched the numerical ones perfectly. Besides that, we reconstructed the GPA by the numerical evolving phases without the high-frequency part, which successfully explained the self-healing property of GPA.(4) The topological charges of Airy-vortex beam and non-integer beam are real-timely measured by PMA camera in the interference path based on polarization phase-shifting method. The meaured results are highly consistent with the theoretical values.