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. 2010 Optical Society of America.
Mari E., Anzolin G., Tamburini F., Prasciolu M., Umbriaco G., Bianchini A., et al. (2010). Fabrication and testing l = 2 Optical Vortex phase masks for coronography. OPTICS EXPRESS, 18(3), 2339-2344 [10.1364/OE.18.002339].
Fabrication and testing l = 2 Optical Vortex phase masks for coronography
Umbriaco G.;
2010
Abstract
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. 2010 Optical Society of America.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
