Influence of gain or absorption media on transmission of partially coherent vortex beams.

Abstract

The results show that the larger the real part of the wave number is, the farther the transmission of PCVBs with hollow distribution will be. The expression of partially coherent vortex beams passing through a gain/absorption medium is derived in this paper based on the generalized Huygens-Fresnel principle. The influences of the refractive index (related to the real part of the wave number) and the gain/absorption characteristics (related to the imaginary part of the wave number) on the transmission of partially coherence vortex beams are investigated. The results show that the larger the real part of the wave number is, the farther the transmission of PCVBs with hollow distribution will be. In gain media, the light power keeps increasing; on the other hand, in absorption media, the light power keeps decreasing. The diffraction effect of the media on the intensity distribution also is mentioned. We discover that, during the transmission, the evolutions of the spectral degree of coherence relate to the real and imaginary parts of the wave number, and the coherence vortices can split and generate. We believe the results of this study are important to the fields of singular optics and optical communications.