MEASUREMENT OF LASER BEAM PROFILE AFTER PROPAGATION THROUGH UNTWISTED AND TWISTED SILICA MICROSTRUCTURED OPTICAL FIBERS WITH A HOLLOW RING CORE DOPED WITH GeO₂. Eureka Journal of Computing Science & Digital Innovation, [S. l.], v. 2, n. 4, p. 12–20, 2026. Disponível em: https://eurekaoa.com/index.php/10/article/view/790. Acesso em: 9 may. 2026.