Digital generation of partially coherent vortex beams

Abstract

We present an experimental technique to generate partially coherent vortex beams with an arbitrary azimuthal index using only a spatial light modulator. Our approach is based on digitally simulating the intrinsic randomness of broadband light passing through a spiral phase plate. We illustrate the versatility of the technique by generating partially coherent beams with different coherence lengths and orbital angular momentum content, without any moving optical device. Consequently, we study its cross-correlation function in a wavefront folding interferometer. The comparison with theoretical predictions yields excellent agreement.

Review on vortex beams with low spatial coherence

“…In above introduction, a RGGD has been used to generate various partially coherent vortex beams with the help of a SPP or spatial light modulator. Recently, a digital method using a SLM has been proposed to generate partially coherent vortex beams [156], and the corresponding experimental setup is shown in Figure 8. A series of complex random phase screens are loaded dynamically by the SLM to generate partially coherent vortex beams.…”

“…Experimental setup for digital generation of partially coherent vortex beams. BE, beam expander; SLM, spatial light modulator; L 1 , L 2 , thin lens; D, aperture[156].…”

Partially Coherent Vortex Beam: From Theory to Experiment

“…Here the correlation singularity is defined as the point where the value of the cross-spectral density or degree of coherence equal zero, while the corresponding phase is undefined. Recently, more and more attention is being paid to partially coherent vortex beams [60][61][62][63][64][65][66][67][68][69][70][71][72][73], more interesting and useful results are being revealed. In this chapter, we will introduce recent theoretical and experimental developments on partially coherent vortex beams.…”

Experimental determination of the azimuthal and radial mode orders of a partially coherent LGpl beam (Invited Paper)

“…More recently, it was shown in Ref. [17] that one can generate a partially coherent vortex beam with an arbitrary azimuthal index using only an SLM. Partially coherent vortex beams exhibit interesting properties, e.g., their cross-correlation function (CCF) displays correlation singularities (i.e., ring dislocations) [14] .…”