Mode volume

In fiber optics, mode volume is the number of bound modes that an optical fiber is capable of supporting. In fiber optics, mode volume is the number of bound modes that an optical fiber is capable of supporting. The mode volume M is approximately given by 4 V 2 π 2 {displaystyle 4V^{2} over pi ^{2}} and V 2 2 ( g g + 2 ) {displaystyle {V^{2} over 2}left({g over g+2} ight)} , respectively for step-index and power-law index profile fibers, where g is the profile parameter, and V is the normalized frequency, which must be greater than 5 for this approximation to be valid.