group index (
N
)
group index (
N
):
In
fiber optics
, for a given
mode
propagating in a
medium
of
refractive index
, the velocity of
light
in vacuum, c, divided by the group velocity of the mode. (
188
)
Note:
For a
plane wave
of
wavelength
, the group index may also be expressed,
where
n
is the
phase
index of wavelength
.
This HTML version of FS-1037C was last generated on Fri Aug 23 00:22:38 MDT 1996
, the velocity of light in vacuum, c, divided by the group velocity of the mode. (188) Note: For a plane wave of wavelength 
, the group index may also be expressed, .