This Fiber Optic Attenuator Coupler, Fixed - ST/UPC 5dB is necessary to prevent over saturating an optical receiver when the optical power is too high. read more This Fiber. ARTIC offers a wide variety of collimation and coupling components that can be used to effectively collimate or couple light out of and into FC/PC, FC/APC, or SMA terminated fiber. Fiber couplers, WDMs, combiners, circulators, and optical switches provide fundamental building blocks for fiber-based. Get low-loss fiber optic adapters/couplers with good repeatability and durability for precisely mating two ends of a fiber optic cable. Multiple connector options available. L-com offers an extensive line of dual wavelength (1310/1550nm) Singlemode fiber optic attenuators. Help others learn more about this product by uploading a video! Amazon.