A bandwidth meter apparatus and method for measuring the bandwidth of a
spectrum of light emitted from a laser input to the bandwidth meter which
may comprise an optical bandwidth monitor providing a first output
representative of a first parameter which is indicative of the bandwidth
or the light emitted from the laser and a second output representative of
a second parameter which is indicative or the bandwidth of the light
emitted from the laser; and, an actual bandwidth calculation apparatus
utilizing the first output and the second output as part of a
multivariable equation employing predetermined calibration variables
specific to the optical bandwidth monitor, to calculate an actual
bandwidth parameter; the multivariable equation comprising a symmetry
sensitive term.