Optical loop attenuator simulating an optical system

A loop attenuator shaped to be interchangeable with a complementary connector that intermates with an optical connector having an optical emitter and an optical detector, the loop attenuator comprising;

• a body of solid material and being dimensioned with an exterior that matches the exterior of the complementary optical connector, thereby to intermate with the optical connector,
• the body having an exterior surface,
• the body having a reflective surface at the exterior surface and formed by moulding a portion of the exterior surface, and
• the reflective surface is constructed to receive optical emission from the emitter and reflect a selective portion of the optical emission for receipt by the detector, and thereby simulate an optical signal of reduced intensity, which optical signal is attributed to an optical system in which the emitter and the detector are installed.