You could use OptiFiber to calculate these values over a range of wavelengths quite easily. Generally the mode diameter is defined for Gaussian-like modes as the radius at which the intensity drops to 1/e^2 of the initial value.
You could use OptiFiber to calculate these values over a range of wavelengths quite easily. Generally the mode diameter is defined for Gaussian-like modes as the radius at which the intensity drops to 1/e^2 of the initial value.