RT Journal Article T1 Evolution of the vortex and the asymmetrical parts of orbital angular momentum in separable first-order optical systems A1 Alieva Krasheninnikova, Tatiana A1 Bastiaans, Martin J. AB We analyze the evolution of the vortex and the asymmetrical parts of orbital angular momentum during its propagation through separable first-order optical systems. We find that the evolution of the vortex part depends on only parameters a(x), a(y), b(x), and b(y) of the ray transformation matrix and that isotropic systems with the same ratio b/a produce the same change of the vortex part of the orbital angular momentum. Finally, it is shown that, when light propagates through an optical fiber with a quadratic refractive-index profile, the vortex part of the orbital angular momentum cannot change its sign more than four times per period. PB Optical Society of America SN 0146-9592 YR 2004 FD 2004-07-15 LK https://hdl.handle.net/20.500.14352/51280 UL https://hdl.handle.net/20.500.14352/51280 LA eng NO © 2004 Optical Society of America. T. Alieva thanks the Spanish Ministry of Science and Technology for financial support of this research (Ramon y Cajal grant and project TIC 2002-01846). M. J. Bastiaan’s e-mail address is m.j.bastiaans@tue.nl. T. Alieva’s e-mail address is talieva@fis.ucm.es. NO Ministry of Science and Technology DS Docta Complutense RD 8 abr 2025