{"id":424808,"date":"2025-03-09T03:35:56","date_gmt":"2025-03-09T03:35:56","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/adiabatic-vertical-taper-coupler-eme-simulation-issue\/"},"modified":"2025-03-09T03:35:56","modified_gmt":"2025-03-09T03:35:56","slug":"adiabatic-vertical-taper-coupler-eme-simulation-issue","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/adiabatic-vertical-taper-coupler-eme-simulation-issue\/","title":{"rendered":"Adiabatic Vertical Taper Coupler EME Simulation Issue"},"content":{"rendered":"
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  1. I am trying to simulate an adiabatic vertical taper coupler in EME, that couples from a 80 nm thick Silicon nitride core waveguide to a 800 nm thick silicon nitride core one. There is SiO2 cladding all around; specifically about 320 nm of it between the two silicon nitride cores. The width of the 80 nm core at the start of its taper is 6 um, while the width of the 800 nm core at the start of its taper from its end is 2 um. <\/li>\n
  2. This is paper is a good example of the structure to what I’m trying to simulate – https:\/\/opg.optica.org\/abstract.cfm?uri=iprsn-2013-IT2A.4<\/em>, but obviously the parameters in my simulation are changed.<\/li>\n
  3. The EME simulation is ran initially with a 100 um taper length; with extrapolation to longer lengths after simulation is complete. And the CVCS cell in the same region is divided into 200 subcells. The mesh step in vertical direction in taper region is 3 nm.<\/li>\n
  4. The problem I’m seeing is then that the simulation results now(image below) do not seem to agree<\/strong> with results of a similar simulation I had done about a year ago<\/strong> wherein I got more almost 100% coupling within several mm of taper coupler length. Additionally, the coupling % seems to reduce with increased length now which does not seem to be correct physics. I have though seen the results get more accurate (increase in coupling %) for longer lengths as I increase subcell count of the CVCS cell; but the RAM usage is already almost a 100 GB. Previously I did not even have to use more than 20 subcells for the results to be accurate.<\/li>\n<\/ol>\n

    <p>Q. I was wondering then what to change in the simulation now to get accurate results and find the taper length at which the coupling would go to like 99%.?<br>\"\"<\/p><\/p>\n","protected":false},"template":"","class_list":["post-424808","topic","type-topic","status-publish","hentry","topic-tag-adiabatic","topic-tag-EME-1","topic-tag-evanescent-waveguide-couplers-2","topic-tag-taper"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27833"],"_bbp_topic_id":["424808"],"_bbp_subscription":["208194","2796"],"_bbp_author_ip":["2600:8802:5113:5800:880d:cbf5:60a7:55ec"],"_bbp_last_reply_id":["426026"],"_bbp_last_active_id":["426026"],"_bbp_last_active_time":["2025-03-18 12:09:12"],"_bbp_reply_count":["3"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["208194","2796"],"_btv_view_count":["324"],"_bbp_topic_status":["unanswered"]},"test":"dboseucsb-edu"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/424808","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\/424808\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=424808"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}