What does the term Return Loss mean?
This is a measurement of light “reflected” from the Connector Face and returned back down the fibre, sometimes referred to as “Back Reflection Loss”. Return loss is measured in decibels (db) and is always quoted by the manufacturer for Single Mode Fibres as the light returned/reflected back to the origin can affect the Laser producing the light and causing “noise” problems. Typical RL values would be between 30db and 60db depending upon the Connector Type and end face finish polishing. The higher the Return Loss figure the better the Connector as this indicates the level of light returned down the fibre. Return Loss (RL) is never quoted for Multi Mode Fibres generally because the Light Sources used in MM systems are LED’s.
