Optical return loss and reflectance are measured using an optical source connected to one input of a 2 X 2 fiber optic coupler. Through a fiber optic coupler, light is launched into the component under test. Reflectance (which has also been called "back reflection" or optical return loss) of a connection is the amount of light that is reflected back up the fiber toward the source by light reflections off the interface of the polished end surface of the mated connectors and air. 8, OptiFiber is able to measure optical return loss. As shown in the figures above, the OCWR Testing setup for reflectance or return loss tests of connectors or passive fiber components per industry standards (TIA FOTP-107 or IEC 61300-3-6) using a light source. Insertion loss, also known as attenuation, is the loss of optical power that occurs when light passes through a fiber optic connector.
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