{"id":395568,"date":"2024-11-27T14:36:23","date_gmt":"2024-11-27T14:36:23","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/metasurface-fdtdreflectivity-and-transmittance-is-greater-than-1-and-big-noise\/"},"modified":"2024-11-27T14:36:23","modified_gmt":"2024-11-27T14:36:23","slug":"metasurface-fdtdreflectivity-and-transmittance-is-greater-than-1-and-big-noise","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/metasurface-fdtdreflectivity-and-transmittance-is-greater-than-1-and-big-noise\/","title":{"rendered":"Metasurface FDTD:reflectivity and transmittance is greater than 1 and big noise"},"content":{"rendered":"<p>&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/11\/27-11-2024-1732717592-mceclip0.png\" \/>&lt;\/p&gt;&lt;p&gt;I made Silicon metasurface and top silicon is for resonance and bottom silicon is for substrate.&lt;\/p&gt;&lt;p&gt;I simulate with 1100nm ~ 2200nm wavelength and I want to check about reflectivity and transmittance.&lt;\/p&gt;&lt;p&gt;Top Simulation PML &#8211; transmittance monitor &#8211; device &#8211; source &#8211; reflectivity monitor &#8211; bottom simulation PML -&gt; each interval is 10um&lt;br&gt;But, when I simulate it, reflectivity and transmittance was greater than 1. And there was big noise.&lt;br&gt;So, I increase simulate time and decrease auto shutoff and add PML layers to 32 with steep angle.&lt;br&gt;But, result was not change. And mesh was 10nm.&lt;br&gt;Can you help me about this problems?&lt;br&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/11\/27-11-2024-1732717992-mceclip1.png\" \/>&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/11\/27-11-2024-1732718003-mceclip2.png\" \/>&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/11\/27-11-2024-1732718016-mceclip3.png\" \/>&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/11\/27-11-2024-1732718062-mceclip5.png\" \/>&lt;\/p&gt;&lt;p&gt;blue line is transmittance, green line is reflectivity.&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-395568","topic","type-topic","status-publish","hentry","topic-tag-reflection-2","topic-tag-simulation","topic-tag-transient"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27833"],"_bbp_topic_id":["395568"],"_bbp_author_ip":["2406:5900:1111:d863:3df6:665:bcee:5a2a"],"_bbp_reply_count":["3"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["453235","473055"],"_btv_view_count":["423"],"_bbp_topic_status":["unanswered"],"_edit_lock":["1732811120:473055"],"_bbp_subscription":["473055","453235"],"_bbp_notification_enabled":["473055"],"_bbp_last_reply_id":["397925"],"_bbp_last_active_id":["397925"],"_bbp_last_active_time":["2024-12-18 22:41:27"]},"test":"yjpeterparknaver-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/395568","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\/395568\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=395568"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}