Background theory of the system and detailed system design are described. Optical Time Domain Reflectometer (OTDR) is an optoelectronic integration precision instrument that makes use of Rayleigh back scattering and Fresnel reflection in optical fiber for optical fibre link chacterization, it is widely used in fiber maintenance, construction, fault location and other. An optical time-domain reflectometer (OTDR) is an optoelectronic instrument used to characterize an optical fiber. It is the optical equivalent of an electronic time domain reflectometer which measures the impedance of the cable or transmission line under test. They characterise the len th, attenuation and return loss (ov se individual events along ink: connection points (splices, connectors), te ng by particles much smaller than the wavelength of the. Electrical signal from FOCUS LWCM for various levels of optical attenuation. 10 ns pulse at 1310 nm excitation from OTDR. Output of DDG for various offset voltage settings. Compression and pulse. In high-density cabling scenarios such as FTTX, data centers, and enterprise networks, the application of MPO/MTP is becoming increasingly widespread, emerging as an important trend in the development of optical communication. Commercial OTDR's measure only the fiber in.