{"id":253571,"date":"2023-03-13T07:46:34","date_gmt":"2023-03-13T07:46:34","guid":{"rendered":"\/forum\/forums\/topic\/understanding-mode-expansion-monitor-in-fdtd-to-measure-propagation-loss\/"},"modified":"2023-03-13T07:46:34","modified_gmt":"2023-03-13T07:46:34","slug":"understanding-mode-expansion-monitor-in-fdtd-to-measure-propagation-loss","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/understanding-mode-expansion-monitor-in-fdtd-to-measure-propagation-loss\/","title":{"rendered":"Understanding Mode Expansion monitor in FDTD to measure propagation loss"},"content":{"rendered":"<p>Hi, i try to find propagation loss using Mode Expansion monitor in FDTD module. but i gotten 0 loss so far.<\/p>\n<p>i am running a simple straight waveguide with the parameters as below:<\/p>\n<p>design size: 100um x 100um<\/p>\n<p>SU8 &#8211; core (width 4um, height 4um)<\/p>\n<p>Air &#8211; cladding<\/p>\n<p>SiO2 &#8211; buffer &#8211; 1um<\/p>\n<p>Si substrate &#8211; 5um<\/p>\n<p>&nbsp;<\/p>\n<p><img decoding=\"async\" title=\"straight waveguide mode expansion monitor\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2023\/03\/13-03-2023-1678693320-mode expansion monitor fdtd.jpg\" alt=\"\"><\/p>\n<p>is there a proper way to place the monitor? i tried putting at the input or in the middle, it gave the same result = ZERO loss.<\/p>\n<p>or i should i should MODE Eigenvalue solver to get the loss reading?<\/p>\n<p>but i wanted to check loss at a certain waveguide area eg. at input vs output<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"template":"","class_list":["post-253571","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["273443","33648"],"_bbp_author_ip":["23.192.164.18"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["1108"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["253571"],"_bbp_forum_id":["27833"],"_bbp_engagement":["33648","273443"],"_bbp_voice_count":["2"],"_bbp_reply_count":["3"],"_bbp_last_reply_id":["274951"],"_bbp_last_active_id":["274951"],"_bbp_last_active_time":["2023-03-15 15:35:54"]},"test":"azarulsaniunimap-edu-my"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/253571","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\/253571\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=253571"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}