Hello Konstantina,
I notice that you originally began asking about this back in July of last year. Have you attempted to build any of these structures and are running into issues?
I would like to clarify something, are you looking to model the evanescent coupling or are you looking at modeling the entire laser system that is shown in image-1-1? OptiFDTD, either the 32-bit or the current release could model the general optical properties of the system but would not model the electrical system or lasing as this is not something included in the FDTD algorithms we have implemented.
Please note that while the 32-bit version of OptiFDTD is free it is a dated version of the software and does not include any of the improvements or upgrades that exist within the current release. There is no support for the the free product other than here in the forums.
Regards,
Scott