Filling factor

Filling factor,   F   {displaystyle ~F~} , is a quantity measuring the efficiency of absorption of pump in the core of a double-clad fiber. Filling factor,   F   {displaystyle ~F~} , is a quantity measuring the efficiency of absorption of pump in the core of a double-clad fiber. The efficiency of absorption of pumping energy in the fiber is an important parameter of a double-clad fiber laser. In many cases this efficiency can be approximated with