Type of fiber – Most single mode fibers have a loss factor of between 0. Fiber optic loss, also known as optical attenuation, refers to the light loss between the transmitter and receiver. Factors causing fiber loss are various, such as intrinsic material absorption, bending, connector loss, etc. Loss is expressed in decibels (dB) and accumulates across all elements of the optical path. In practical networks, total link loss is composed of. This is similar to the single-ended loss measurement of terminated cables, but uses the splice instead of connectors at the source end and a bare fiber adapter to connect the fiber to the power meter.