Mari Elettra, Anzolin Gabriele, Tamburini Fabrizio, Prasciolu Mauro, Umbriaco Gabriele, Bianchini Antonio, Barbieri Cesare, Romanato Filippo
CISAS G Colombo, University of Padua, Via Venezia 15 35131, Padova, Italy.
Opt Express. 2010 Feb 1;18(3):2339-44. doi: 10.1364/OE.18.002339.
In this paper we present the fabrication process and tests of two different types of l = 2 spiral phase plates (SPPs), designed for an Optical Vortex Coronagraph (OVC) in the visible wavelength regime. Each phase mask is realized dividing the spirals area in sectors respectively of 8 and 512 of levels using lithographic nanofabrication approach. The SPPs produces different optical vortices (OVs) with topological charge l that depends on the number of steps and on the wavelength. We found that the residual light in the central dark region of the OV tends to zero as the number of steps increases.
在本文中，我们展示了两种不同类型的l = 2螺旋相位板（SPP）的制造工艺和测试结果，这些螺旋相位板是为可见光波段的光学涡旋日冕仪（OVC）设计的。每个相位掩模通过光刻纳米制造方法，将螺旋区域分别划分为8级和512级的扇区来实现。螺旋相位板产生具有不同拓扑电荷l的不同光学涡旋（OV），拓扑电荷l取决于级数和波长。我们发现，随着级数增加，光学涡旋中心暗区的残余光趋于零。
