A fiber-optic adapter — sometimes called a coupler or bulkhead coupler — is a passive mechanical interface that mates and aligns two terminated optical fibers (i., two fiber connectors) such that light can reliably pass from one to the other with minimal insertion loss and maximum return loss. Fiber optic adapters play a vital role in modern optical communication systems by enabling seamless connections between fiber optic cables. These small yet essential components ensure efficient data transmission, reduce signal loss, and maintain system integrity (1).
