Chinese Optics Letters, 2013, 11 (5): 052601, Published Online: Apr. 2, 2013
Polarization and amplitude hybrid modulation of longitudinally polarized subwavelength-sized optical needle Download: 818次
Abstract
We present a method of both polarization and amplitude modulations on an incident beam to obtain a longitudinally polarized subwavelength-sized optical needle. A 4-f system with a spatial light modulator is used to generate experimentally a two-mode alternate cylindrical vector beam by polarization modulation, enhancing performance and facilitating implementation. We optimize the beam focusing properties after passing the beam through an annular aperture to obtain amplitude modulation by the simulated annealing algorithm. Numerical results indicate that a sharp focal spot (0.417\lambda) with a long focal depth (8\lambda) and a strong longitudinally polarized field can be easily achieved.
Lijiao Guo, Changjun Min, Shibiao Wei, Xiaocong Yuan. Polarization and amplitude hybrid modulation of longitudinally polarized subwavelength-sized optical needle[J]. Chinese Optics Letters, 2013, 11(5): 052601.