Generation of controllable nondiffracting beams using multimode optical fibers

A method of generating nondiffracting beams using multimode optical fibers is reported. When a large-core multimode fiber is spliced onto a piece of single-mode fiber, only linearly polarized (LP(0,n)) modes are excited inside the multimode fiber segment because of mode orthogonality and on-axis excitation. Since the excited LP(0,n) modes are actually Bessel fields with different transverse wave vectors truncated by the core of the multimode fiber, the beam exiting the multimode fiber facet can form a variety of readily controllable and nearly nondiffracting optical patterns resulting from interference of apertured Bessel fields.