A fiber-optic adapter β sometimes called a coupler or bulkhead coupler β is a passive mechanical interface that mates and aligns two terminated optical fibers (i. It plays a key role in maintaining core-to-core alignment, allowing optical signals to pass through with minimal insertion loss and stable performance. Consequently, they ensure that the precious data, transmitted as pulses of light, continues its journey with minimal loss and maximum integrity. β What Are Fiber Optic Adapters? Fiber optic. Fiber optic adapters, also known as couplers, play a crucial role in fiber optic networks by providing a connection point between two fiber optic connectors. A fiber optic coupler works by precisely.