Mangini F, Ferraro M, Zitelli M, Kalashnikov V, Niang A, Mansuryan T, Frezza F, Tonello A, Couderc V, Aceves A B, Wabnitz S
Department of Information Engineering (DII), University of Brescia, Via Branze 38, 25123, Brescia, Italy.
Department of Information Engineering, Electronics and Telecommunications (DIET), Sapienza University of Rome, Via Eudossiana 18, 00184, Rome, Italy.
Sci Rep. 2021 Jun 22;11(1):13030. doi: 10.1038/s41598-021-92313-w.
We demonstrate a new practical approach for generating multicolour spiral-shaped beams. It makes use of a standard silica optical fibre, combined with a tilted input laser beam. The resulting breaking of the fibre axial symmetry leads to the propagation of a helical beam. The associated output far-field has a spiral shape, independently of the input laser power value. Whereas, with a high-power near-infrared femtosecond laser, a visible supercontinuum spiral emission is generated. With appropriate control of the input laser coupling conditions, the colours of the spiral spatially self-organize in a rainbow distribution. Our method is independent of the laser source wavelength and polarization. Therefore, standard optical fibres may be used for generating spiral beams in many applications, ranging from communications to optical tweezers and quantum optics.
我们展示了一种生成多色螺旋形光束的新实用方法。它利用标准石英光纤，结合倾斜的输入激光束。光纤轴向对称性的破坏导致螺旋光束的传播。相关的输出远场具有螺旋形状，与输入激光功率值无关。而使用高功率近红外飞秒激光时，会产生可见的超连续螺旋发射。通过适当控制输入激光耦合条件，螺旋的颜色在空间上自组织成彩虹分布。我们的方法与激光源波长和偏振无关。因此，标准光纤可用于许多应用中生成螺旋光束，从通信到光镊和量子光学。
