Hello, I am trying to simulate SiN waveguide to SMF and extract the S parameters or just see the transmission into the fiber mode to get the coupling loss. <\/p>\n
I do not use ports because I break up the simulation into two parts and ports cannot export\/import sources. I followed this example to perform the export\/import: https:\/\/optics.ansys.com\/hc\/en-us\/articles\/360034383034-Using-monitor-data-to-define-the-spatial-field-profile-of-a-source-in-FDTD<\/p>\n
Part 1) The inverse taper in the SiN waveguide to convert\/expand the mode to better match MFD of the fiber. I use a mode source going towards the fiber from the nominal WG width and I export the fields just before the interface to the fiber.<\/p>\n
Part 2) The WG to SMF interface. On the PIC side, I import the source using the export from part 1. On the fiber side, I have modal expansion and DFT monitors tied together to get the transmission into the fiber mode.<\/p>\n
My original modal source for part 1 is the fundamental TE mode (it’s TE mode WG), I set wavelength from 1.5um to 1.6um, my mesh setting is “3” and I <\/p>\n
When I try to change the inverse taper to help me design the coupler and find the correct length, sometimes I get reasonably results, but mostly I don’t. See these videos:<\/p>\n
300um taper 1500nm to 250nm: https:\/\/youtu.be\/4w1wdh_IBDY<\/p>\n
200um taper 1500nm to 250nm: https:\/\/youtu.be\/cDQYOpT9qME<\/p>\n
100um taper 1500nm to 250nm: https:\/\/youtu.be\/8mfLJqDixOg<\/p>\n
The 300um one works as I expect and I get reasonable result at the end (total transmission into fiber mode ~50% or -3dB). However the 200um and 100um I get a very long simulation where a strange field grows from the PIC side. You can easily see in the videos at the end. This field can’t be physical and I must have something set incorrectly, any ideas?<\/p>\n
Also, you can see all the videos the majority of the time nothing is happening. Is there any way to speed this up and simulate only the important parts?<\/p>\n
Thank you,<\/p>\n
George<\/p>\n","protected":false},"template":"","class_list":["post-356474","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["340910","2592"],"_bbp_author_ip":["23.206.193.41"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["331"],"_bbp_topic_status":["unanswered"],"_bbp_topic_id":["356474"],"_bbp_forum_id":["27833"],"_bbp_engagement":["2592","340910"],"_bbp_voice_count":["2"],"_bbp_reply_count":["5"],"_bbp_last_reply_id":["358235"],"_bbp_last_active_id":["358235"],"_bbp_last_active_time":["2024-03-20 23:49:21"]},"test":"gnelsonsunypoly-edu"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/356474","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\/356474\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=356474"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}