INTERCONNECT straight waveguide model - difference between effective and group index


#1

The straight waveguide model in INTERCONNCT has two different properties: The effective index and the group index. What is the difference between them?


#2

The group index is related to the effective index by a derivative as function of frequency, as described in the ‘Implementation details’ section of the following page:
http://docs.lumerical.com/en/index.html?ref_primitive_elements_straight_waveguide.html

I hope this answers your question. If not, please provide a more complete description of your question.

Best regards,
Chris