Low insertion-and high return-loss optical connectors with spherically convex-polished end

PC connectors with spherically convex-polished ends, whose fibre ends make close contact, have recently been developed. This connector features extremely low insertion-and high return-loss characteristics, and is also easily produced with good environmental performance. For a single-mode PC connector, the average insertion loss is measured to be as small as 0.17 dB with a return loss of 28 dB. Detailed evaluation of this connector is now under way for use in a trial optical transmission system.