{"id":393945,"date":"2024-11-15T01:25:54","date_gmt":"2024-11-15T01:25:54","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/edge-coupler-eme-example-issue\/"},"modified":"2024-11-15T01:25:54","modified_gmt":"2024-11-15T01:25:54","slug":"edge-coupler-eme-example-issue","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/edge-coupler-eme-example-issue\/","title":{"rendered":"Edge Coupler EME Example Issue"},"content":{"rendered":"<p>&lt;p&gt;Hi,&lt;\/p&gt;&lt;p&gt;I am trying to simulate edge coupler with EME, and is especially interested in evaluating the substrate leakage.&nbsp;&lt;\/p&gt;&lt;p&gt;I downloaded the simu files from this example page(https:\/\/optics.ansys.com\/hc\/en-us\/articles\/360042305354-Edge-coupler) and decided to try to reproduce the results given in the page.&lt;\/p&gt;&lt;p&gt;The FDE\/EME simulation results without substrate perfectly matches the graph given in the page (T increase as taper length increase and get Infinitely approaching 1). But the EME simulation with substrate produce very strange results (see plot atatched). The coupling is up to 80% for short taper and approach 0 on longer tapers, which doesn&#8217;t make sense and doesn&#8217;t match what&#8217;s shown in the example page.&lt;\/p&gt;&lt;p&gt;To debug, I checked the mode solver of each cell and confirmed that the interested mores can be found (along with some unphysical modes in the substrate). Also I tried to use the codes provided (setup_index_search_per_cell.lsf and sweep_length.lsf) to break down the group2 and set target mode index for each cell seperately. It gives me the same result.&nbsp;&lt;\/p&gt;&lt;p&gt;I also tried to disable the substrate and redo the propagration\/parameter sweep. It gives me correct answer, so the problem should be attribiute to the substrate. But I spent a lot of time trying to debugging and couldn&#8217;t get the same results are shown in the example page. Please help. Thanks!&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/11\/15-11-2024-1731633461-eme_edge_coupler.png\" alt=\"EME without substrate\" \/>&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-393945","topic","type-topic","status-publish","hentry","topic-tag-coupler-1","topic-tag-EME-1","topic-tag-lumerical"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["45962","473055"],"_bbp_author_ip":["206.87.146.107"],"_btv_view_count":["566"],"_bbp_topic_status":["unanswered"],"_bbp_notification_enabled":["45962","473055"],"_bbp_topic_id":["393945"],"_bbp_forum_id":["27833"],"_bbp_engagement":["45962","473055"],"_bbp_voice_count":["2"],"_bbp_reply_count":["6"],"_bbp_last_reply_id":["398338"],"_bbp_last_active_id":["398338"],"_bbp_last_active_time":["2024-12-23 15:17:10"]},"test":"mathewyuece-ubc-ca"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/393945","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":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/393945\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=393945"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}