Free-space optical communication with bottle vortex beam under atmospheric turbulence and finite receiving aperture

To enhance the performance of orbital angular momentum (OAM) beams in Free-Space Optical (FSO) communications under conditions of atmospheric turbulence and finite receiving aperture, we propose a design for parabolic trajectory Bottle vortex beams (BVBs) using the caustic line method. Compared to conventional OAM beams, BVBs exhibit a smaller beam diameter at the receiver while displaying enhanced resistance to turbulence. Under conditions of strong turbulence D/r
0
= 4 and a receiver aperture of 20 mm, the average received optical power of BVBs is increased by 12 dB and 40 dB compared to OAM beams, respectively.