Figure 7
From: Spatio-temporal coherence mapping of few-cycle vortex pulses
Multichannel vortex generation.
The grey value map was transferred into a phase map of SLM1 for the generation of a 2 × 2 array of thin spiral phase plates (circular areas) with a period of 260 pixels (2.1 mm). To reduce the background signal in the plane of interest, a checkered pattern (2 × 2 pixels per square) was applied to the passive areas between the phase plates (inset). The dark and bright part corresponds to a higher and lower effective refractive index, respectively.
