Although current splices and connectors are proving to be quite reliable there is definite room for improvement. The major issue in reliability is continuing quality assurance of the assembly processes. We need connectors that do not generate debris as they are coupled. Connectors must latch positively and they must retain physical contact throughout the range of environmental conditions to which they are exposed. We also need a better understanding of the processes that determine the reliability of the reflectance performance: bonding of the fibers into the ferrule, and polishing.
William W. Wood,
"Reliability of optical connectors and splices", Proc. SPIE 2074, Fiber Optics Reliability and Testing: Benign and Adverse Environments, (1 March 1994); doi: 10.1117/12.168637; https://doi.org/10.1117/12.168637