{"id":361384,"date":"2024-04-09T17:34:47","date_gmt":"2024-04-09T17:34:47","guid":{"rendered":"\/forum\/forums\/reply\/361384\/"},"modified":"2024-04-09T17:34:47","modified_gmt":"2024-04-09T17:34:47","slug":"361384","status":"publish","type":"reply","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/361384\/","title":{"rendered":"Reply To: FDE simulation shows negative effective refractive index"},"content":{"rendered":"<p>&lt;p&gt;Hi Victoria,&lt;\/p&gt;&lt;p&gt;I will recommend unchecking that option for now. I believe the the gain is most likely because of the PML. When you are simulating a bent waveguide, the radiation from the waveguide (a lot of which is opposite to the direction of the bend) can interact with the PML boundaries to create artificial gain\/loss. So, it is recommended to limit these as much as possible by increasing the simulation span. I will ask you to run the simulation for different simulation spans, this is also called convergence testing. Start at the current value and then increase the FDE simulation span, at some point you would see the losses converge to a single value even even when you increase the simulation span. This would be the actual loss you are looking for.&lt;\/p&gt;&lt;p&gt;Regards,&lt;br&gt;Amrita&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-361384","reply","type-reply","status-publish","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 4.9.10 - aioseo.com -->\n\t<meta name=\"description\" content=\"Hi Victoria,I will recommend unchecking that option for now. I believe the the gain is most likely because of the PML. When you are simulating a bent waveguide, the radiation from the waveguide (a lot of which is opposite to the direction of the bend) can interact with the PML boundaries to create artificial gain\/loss.\" \/>\n\t<meta name=\"robots\" content=\"max-image-preview:large\" \/>\n\t<link rel=\"canonical\" href=\"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/361384\/\" \/>\n\t<meta name=\"generator\" content=\"All in One SEO (AIOSEO) 4.9.10\" \/>\n\t\t<meta property=\"og:locale\" content=\"en_US\" \/>\n\t\t<meta property=\"og:site_name\" content=\"Ansys Learning Forum | Ansys Innovation Space\" \/>\n\t\t<meta property=\"og:type\" content=\"article\" \/>\n\t\t<meta property=\"og:title\" content=\"Reply To: FDE simulation shows negative effective refractive index | Ansys Learning Forum\" \/>\n\t\t<meta property=\"og:description\" content=\"Hi Victoria,I will recommend unchecking that option for now. I believe the the gain is most likely because of the PML. When you are simulating a bent waveguide, the radiation from the waveguide (a lot of which is opposite to the direction of the bend) can interact with the PML boundaries to create artificial gain\/loss.\" \/>\n\t\t<meta property=\"og:url\" content=\"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/361384\/\" \/>\n\t\t<meta property=\"article:published_time\" content=\"2024-04-09T17:34:47+00:00\" \/>\n\t\t<meta property=\"article:modified_time\" content=\"2024-04-09T17:34:47+00:00\" \/>\n\t\t<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n\t\t<meta name=\"twitter:title\" content=\"Reply To: FDE simulation shows negative effective refractive index | Ansys Learning Forum\" \/>\n\t\t<meta name=\"twitter:description\" content=\"Hi Victoria,I will recommend unchecking that option for now. I believe the the gain is most likely because of the PML. When you are simulating a bent waveguide, the radiation from the waveguide (a lot of which is opposite to the direction of the bend) can interact with the PML boundaries to create artificial gain\/loss.\" \/>\n\t\t<script type=\"application\/ld+json\" class=\"aioseo-schema\">\n\t\t\t{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/reply\\\/361384\\\/#breadcrumblist\",\"itemListElement\":[{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum#listItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/reply\\\/361384\\\/#listItem\",\"name\":\"Reply To: FDE simulation shows negative effective refractive index\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/reply\\\/361384\\\/#listItem\",\"position\":2,\"name\":\"Reply To: FDE simulation shows negative effective refractive index\",\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum#listItem\",\"name\":\"Home\"}}]},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/#organization\",\"name\":\"Ansys Learning Forum\",\"description\":\"Ansys Innovation Space\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/\"},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/reply\\\/361384\\\/#webpage\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/reply\\\/361384\\\/\",\"name\":\"Reply To: FDE simulation shows negative effective refractive index | Ansys Learning Forum\",\"description\":\"Hi Victoria,I will recommend unchecking that option for now. I believe the the gain is most likely because of the PML. When you are simulating a bent waveguide, the radiation from the waveguide (a lot of which is opposite to the direction of the bend) can interact with the PML boundaries to create artificial gain\\\/loss.\",\"inLanguage\":\"en-US\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/#website\"},\"breadcrumb\":{\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/reply\\\/361384\\\/#breadcrumblist\"},\"datePublished\":\"2024-04-09T17:34:47+00:00\",\"dateModified\":\"2024-04-09T17:34:47+00:00\"},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/#website\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/\",\"name\":\"Ansys Learning Forum\",\"description\":\"Ansys Innovation Space\",\"inLanguage\":\"en-US\",\"publisher\":{\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/#organization\"}}]}\n\t\t<\/script>\n\t\t<!-- All in One SEO -->\n\n","aioseo_head_json":{"title":"Reply To: FDE simulation shows negative effective refractive index | Ansys Learning Forum","description":"Hi Victoria,I will recommend unchecking that option for now. I believe the the gain is most likely because of the PML. When you are simulating a bent waveguide, the radiation from the waveguide (a lot of which is opposite to the direction of the bend) can interact with the PML boundaries to create artificial gain\/loss.","canonical_url":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/361384\/","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"BreadcrumbList","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/361384\/#breadcrumblist","itemListElement":[{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum#listItem","position":1,"name":"Home","item":"https:\/\/innovationspace.ansys.com\/forum","nextItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/361384\/#listItem","name":"Reply To: FDE simulation shows negative effective refractive index"}},{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/361384\/#listItem","position":2,"name":"Reply To: FDE simulation shows negative effective refractive index","previousItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum#listItem","name":"Home"}}]},{"@type":"Organization","@id":"https:\/\/innovationspace.ansys.com\/forum\/#organization","name":"Ansys Learning Forum","description":"Ansys Innovation Space","url":"https:\/\/innovationspace.ansys.com\/forum\/"},{"@type":"WebPage","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/361384\/#webpage","url":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/361384\/","name":"Reply To: FDE simulation shows negative effective refractive index | Ansys Learning Forum","description":"Hi Victoria,I will recommend unchecking that option for now. I believe the the gain is most likely because of the PML. When you are simulating a bent waveguide, the radiation from the waveguide (a lot of which is opposite to the direction of the bend) can interact with the PML boundaries to create artificial gain\/loss.","inLanguage":"en-US","isPartOf":{"@id":"https:\/\/innovationspace.ansys.com\/forum\/#website"},"breadcrumb":{"@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/361384\/#breadcrumblist"},"datePublished":"2024-04-09T17:34:47+00:00","dateModified":"2024-04-09T17:34:47+00:00"},{"@type":"WebSite","@id":"https:\/\/innovationspace.ansys.com\/forum\/#website","url":"https:\/\/innovationspace.ansys.com\/forum\/","name":"Ansys Learning Forum","description":"Ansys Innovation Space","inLanguage":"en-US","publisher":{"@id":"https:\/\/innovationspace.ansys.com\/forum\/#organization"}}]},"og:locale":"en_US","og:site_name":"Ansys Learning Forum | Ansys Innovation Space","og:type":"article","og:title":"Reply To: FDE simulation shows negative effective refractive index | Ansys Learning Forum","og:description":"Hi Victoria,I will recommend unchecking that option for now. I believe the the gain is most likely because of the PML. When you are simulating a bent waveguide, the radiation from the waveguide (a lot of which is opposite to the direction of the bend) can interact with the PML boundaries to create artificial gain\/loss.","og:url":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/361384\/","article:published_time":"2024-04-09T17:34:47+00:00","article:modified_time":"2024-04-09T17:34:47+00:00","twitter:card":"summary_large_image","twitter:title":"Reply To: FDE simulation shows negative effective refractive index | Ansys Learning Forum","twitter:description":"Hi Victoria,I will recommend unchecking that option for now. I believe the the gain is most likely because of the PML. When you are simulating a bent waveguide, the radiation from the waveguide (a lot of which is opposite to the direction of the bend) can interact with the PML boundaries to create artificial gain\/loss."},"aioseo_meta_data":{"post_id":"361384","title":null,"description":null,"keywords":null,"keyphrases":null,"primary_term":null,"canonical_url":null,"og_title":null,"og_description":null,"og_object_type":"default","og_image_type":"content","og_image_url":null,"og_image_width":null,"og_image_height":null,"og_image_custom_url":null,"og_image_custom_fields":null,"og_video":null,"og_custom_url":null,"og_article_section":null,"og_article_tags":null,"twitter_use_og":true,"twitter_card":"default","twitter_image_type":"default","twitter_image_url":null,"twitter_image_custom_url":null,"twitter_image_custom_fields":null,"twitter_title":null,"twitter_description":null,"schema":{"blockGraphs":[],"customGraphs":[],"default":{"data":{"Article":[],"Course":[],"Dataset":[],"FAQPage":[],"Movie":[],"Person":[],"Product":[],"ProductReview":[],"Car":[],"Recipe":[],"Service":[],"SoftwareApplication":[],"WebPage":[]},"graphName":"","isEnabled":true},"graphs":[]},"schema_type":"default","schema_type_options":null,"pillar_content":false,"robots_default":true,"robots_noindex":false,"robots_noarchive":false,"robots_nosnippet":false,"robots_nofollow":false,"robots_noimageindex":false,"robots_noodp":false,"robots_notranslate":false,"robots_max_snippet":null,"robots_max_videopreview":null,"robots_max_imagepreview":"large","priority":null,"frequency":null,"local_seo":null,"limit_modified_date":false,"created":"2024-10-28 16:49:38","updated":"2026-08-20 16:34:00","ai":null,"breadcrumb_settings":null,"seo_analyzer_scan_date":null},"aioseo_breadcrumb":"<div class=\"aioseo-breadcrumbs\"><span class=\"aioseo-breadcrumb\">\n\t\t\t<a href=\"https:\/\/innovationspace.ansys.com\/forum\" title=\"Home\">Home<\/a>\n\t\t<\/span><span class=\"aioseo-breadcrumb-separator\">&raquo;<\/span><span class=\"aioseo-breadcrumb\">\n\t\t\tReply To: FDE simulation shows negative effective refractive index\n\t\t<\/span><\/div>","aioseo_breadcrumb_json":[{"label":"Home","link":"https:\/\/innovationspace.ansys.com\/forum"},{"label":"Reply To: FDE simulation shows negative effective refractive index","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/361384\/"}],"acf":[],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/replies\/361384","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/replies"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/types\/reply"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/replies\/361384\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=361384"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}