{"id":219344,"date":"2022-07-21T14:16:35","date_gmt":"2022-07-21T14:16:35","guid":{"rendered":"\/forum\/forums\/topic\/why-the-kerrnonlinear-model-cause-energy-loss-in-pulse-propagation\/"},"modified":"2022-07-21T14:16:35","modified_gmt":"2022-07-21T14:16:35","slug":"why-the-kerrnonlinear-model-cause-energy-loss-in-pulse-propagation","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/why-the-kerrnonlinear-model-cause-energy-loss-in-pulse-propagation\/","title":{"rendered":"Why the kerrnonlinear model cause energy loss in pulse propagation ?"},"content":{"rendered":"

Hello!I am trying to study the influence of kerr effect on optical pulse propagation in a SOI waveguide by using the <\/span>“<\/span>kerrnonlinear<\/span>”<\/span>material plugin that Lumerical provide. Strangely,the simulation result shows about 45% of energy loss that shouldn<\/span>’<\/span>t have appeared(kerr effect only change the refractive index).I<\/span>’<\/span>m wondering where the loss derived from, here are the simlulation details: <\/span><\/p>\n

The parameters of kerrnonlinear model are specified below: Permittivity equals the square of 3.48(the refractive index of silicon in 1550nm), and Chi3 value is derived from<\/span>“<\/span>FDTD Analysis of Two-Photon Absorption and Free-Carrier Absorption in Si High-Index-Contrast Waveguides<\/span>”<\/span><\/p>\n

 <\/p>\n

The SOI waveguide is 450nm*220nm and surrounded by SiO2,the propagation length is 25 micrometers.At 0.1 and 25 micrometers away from the TE mode source I set point and 2D timemonitors to check the spectrum and pulse power:<\/span><\/p>\n

 <\/p>\n

The pulse length is 200fs at 1550nm. In order to see the broadened spectrum, the source amplitude is set to 3e9V\/m:<\/span><\/p>\n

Here are the results:<\/span><\/p>\n

The <\/span>“<\/span>power_in<\/span>”<\/span>and <\/span>“<\/span>power_out<\/span>”<\/span>are the transmitted power calculated by integrating the Poynting vector, which shows 45% loss of pulse energy.the intensity of E on XOY plane also gradually decreased.<\/span><\/p>\n

Thank you and looking forward to your reply!<\/span><\/p>\n","protected":false},"template":"","class_list":["post-219344","topic","type-topic","status-closed","hentry","topic-tag-fdtd","topic-tag-non-linear"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["253916","2592"],"_bbp_author_ip":["23.218.93.53"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["702"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["219344"],"_bbp_forum_id":["27833"],"_bbp_engagement":["2592","253916"],"_bbp_voice_count":["2"],"_bbp_reply_count":["5"],"_bbp_last_reply_id":["223044"],"_bbp_last_active_id":["223044"],"_bbp_last_active_time":["2022-08-02 15:45:16"]},"test":"qza0505stu-xidian-edu-cn"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/219344","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\/219344\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=219344"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}