Abstract: A filled-core optical fiber (100) spliced to conventional, solid core optical transmission fiber (175) and a related method of making the same are provided. The optical fiber (100) comprises a core region (140), a cladding ring (120) enclosing the core region (120), and an outer cladding layer (160). A fill hole (115) is formed in the optical fiber (100) which extends from an outer sidewall (110) to the core region (140). The fill hole (115) is for introducing optical material (165) into the core region (140). The optical material (165) is introduced into the core region (140) after opposing ends (121, 122) of the optical fiber (100) are spliced to the free ends (176, 176) of conventional, solid core optical transmission fiber (175). The optical material (165) is introduced into core region (140) after splicing to avoid damage to the optical material (165) due to exposure to high temperatures generated during splicing.