An optical loop-back attenuator (2) includes a frame (22), a cover (21)
attached to the frame, an optical fiber (24), an optical fiber fixture
(23) retaining and fixing the optical fiber, and two SC plug connectors
(25) receiving and retaining opposite ends of the optical fiber therein.
The frame and the cover cooperate to fittingly receive the optical fiber,
the optical fiber fixture and portions of the SC plug connectors therein.
The optical fiber has a bent part (242) which is configured to be
semicircular or to have another suitable shape that achieves a desired
attenuation.
