St. Petersburg Polytechnic University Journal: Physics and Mathematics Научно-технические ведомости СПбГПУ. Физико-математические науки 2304-9782, 2618-8686, 2405-7223 18 The intensity distributions of the light near the output end of the optical fiber in the presence of optical vortices Распределения интенсивности света вблизи выходного торца волоконного световода при наличии оптических вихрей Kiesewetter Dmitry Ilin Nikita 10 09 2013 3 177 151 155

The effect of rotation of speckle of multimode optical fiber has been confirmed experimentally when moving plane observations along the fiber axis near the surface of the output end. Using the calculation of cross correlation function between the distributions of intensity the angular speed of rotation of speckle was determined.

 optical fiber optical vortex speckle intensity distribution of light output end of optical fiber