{"id":167616,"date":"2022-03-23T03:37:13","date_gmt":"2022-03-23T03:37:13","guid":{"rendered":"\/forum\/forums\/topic\/how-to-get-farfield-projection-for-periodic-structure\/"},"modified":"2022-05-03T21:18:03","modified_gmt":"2022-05-03T21:18:03","slug":"how-to-get-farfield-projection-for-periodic-structure","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/how-to-get-farfield-projection-for-periodic-structure\/","title":{"rendered":"How to get farfield projection for periodic structure?"},"content":{"rendered":"<div class=\"Item-Body\">\n<div class=\"Message userContent\">\n<p>Hi,<\/p>\n<p>According to <a href=\"https:\/\/support.lumerical.com\/hc\/en-us\/articles\/360034914793-Understanding-the-Assume-Periodic-option-in-far-field-projections\" rel=\"nofollow\">this page<\/a>, using farfield3D on a single unit cell of a periodic structure will result in significant diffraction artifacts. It states that, if the structure is infinitely periodic, then &#039;Grating Projection&#039; functions should be used. However, it is not clear to me which grating functions one should use to get a 2D field intensity profile for the far field. &#039;grating&#039; only returns fraction of power in each beam, so cannot be used to get a 2D color plot of the field profile. Could you let me know which grating functions are equivalent to the &#039;farfield3D&#039; function, which can be used to plot a 2D color map of the field intensity together with farfieldux and farfielduy? Or is the only option to include several periods within the FDTD region rather than just 1 and use the farfield3D function then? Thank you in advance.<\/p>\n","protected":false},"template":"","class_list":["post-167616","topic","type-topic","status-closed","hentry","topic-tag-farfield-2","topic-tag-fdtd","topic-tag-gratings-farfield-2","topic-tag-LumericalFDTD-1","topic-tag-photonics"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_btv_view_count":["1006"],"_bbp_likes_count":["0"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["167616"],"_bbp_forum_id":["27833"],"_bbp_engagement":["707","2592","220285","255193"],"_bbp_voice_count":["4"],"_bbp_reply_count":["7"],"_bbp_last_reply_id":["209269"],"_bbp_last_active_id":["209269"],"_bbp_last_active_time":["2022-05-03 21:18:03"]},"test":"mfoleycaltech-edu"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/167616","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\/167616\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=167616"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}