Attenuation in fiber optics is the gradual loss of light signal strength as it travels through a fiber cable. A standard single-mode fiber operating at 1550 nm loses. It focuses on decibels (dB), decibels per milliwatt (dBm), attenuation and measurements, and provides an introduction to optical fibers. There are no specific requirements for this document. This document is not restricted to specific software and hardware versions. This is a rather advanced discussion concerning the field of optical fiber. Optical fiber is our first. Present communications use HFs (high-frequencies), thus the mediums which have a smooth-attenuation in all frequencies like fiber optics are employed instead of normal copper circuits.