{"id":436936,"date":"2025-07-15T18:06:38","date_gmt":"2025-07-15T18:06:38","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/modal-overlap-for-far-field-projection-farfieldexact3d\/"},"modified":"2025-07-31T13:21:09","modified_gmt":"2025-07-31T13:21:09","slug":"modal-overlap-for-far-field-projection-farfieldexact3d","status":"answered","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/modal-overlap-for-far-field-projection-farfieldexact3d\/","title":{"rendered":"Modal overlap for far field projection (farfieldexact3d)"},"content":{"rendered":"<p>&lt;p&gt;&lt;p&gt;Hello,&lt;\/p&gt;&lt;p&gt;I am using Lumerical MODE software to find the coupling efficiency between two single-mode waveguides as a function of the air gap in between. For the no gap case, I would simulate one of the mode and save it into d-card and apply Mode Overlap analysis after simulating the second mode with Position Optimization function.&nbsp;&lt;\/p&gt;&lt;p&gt;If you add a gap, I would consider propagating the mode into air for a known distance before using the same analysis. The propagation in air can be done using Planar Far-Field analysis tab but then there is then no way to use Mode Overlap analysis on such a generated mode section. I found the script equivalent as the farfieldexact3d function and I managed to use overlap between a mode from FDE solver and one generated by farfieldexact3d.&lt;\/p&gt;&lt;p&gt;My issue is that there is no way of using Optimizeposition function as it works only with a mode saved into the d-card and it is impossible to import anything generated by farfieldexact3d function as a d-card mode.&lt;\/p&gt;&lt;p&gt;Could you please suggest a way to perform a mode overlap with position optimisation, or an alternative analysis, between a mode from far-field projection and a standard FDE mode?&lt;\/p&gt;&lt;p&gt;Thanks for your help&lt;\/p&gt;&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-436936","topic","type-topic","status-answered","hentry","topic-tag-far-field-1","topic-tag-MODE-1","topic-tag-overlap"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27833"],"_bbp_topic_id":["436936"],"_bbp_subscription":["242609","473055","2796"],"_bbp_author_ip":["130.209.178.213"],"_bbp_last_reply_id":["437550"],"_bbp_last_active_id":["437550"],"_bbp_last_active_time":["2025-07-23 11:55:19"],"_bbp_reply_count":["7"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["3"],"_bbp_engagement":["242609","473055","2796"],"_btv_view_count":["473"],"_bbp_topic_status":["answered"],"_bbp_notification_enabled":["473055"],"_edit_last":["473055"],"_bbp_revision_log":["a:1:{i:437383;a:2:{s:6:\"author\";i:473055;s:6:\"reason\";s:0:\"\";}}"]},"test":"eugenio-digaetanoglasgow-ac-uk"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/436936","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":1,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/436936\/revisions"}],"predecessor-version":[{"id":437383,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/436936\/revisions\/437383"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=436936"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}