{"id":363356,"date":"2024-04-21T14:18:17","date_gmt":"2024-04-21T14:18:17","guid":{"rendered":"\/forum\/forums\/reply\/363356\/"},"modified":"2024-04-21T14:18:17","modified_gmt":"2024-04-21T14:18:17","slug":"363356","status":"publish","type":"reply","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/363356\/","title":{"rendered":"Reply To: Question regarding the auto shut off in FDTD simulation."},"content":{"rendered":"

<p>Hi Amrita,<\/p><p>Thank you for the confirmation.<\/p><p>I attempted to run a broadband simulation for 0.4 to 0.8 micrometers using mesh cells per wavelength at 6, 10, 14, and 18. I did not change the auto shutoff level for this simulation and continued to use the default auto shutoff value, which is 1e-05.<\/p><p><\/p><p>Below are the results of the simulation:<\/p><\/p>\n

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  1. Mesh cell 6:<\/li>\n<\/ol>\n

    <p><\/p><p>2. Mesh cell 10:<\/p><p><\/p><p>3. Mesh cell 14:<\/p><p><\/p><p>4. Mesh cell 18:<\/p><p><\/p><p> <\/p><p>I also tried to capture the Ey here:<\/p><p><\/p><p> <\/p><p>Furthermore, I ran simulations using a broadband spectrum (0.4 to 0.8 micrometers) with different auto shutoff levels: 1e-05, 1e-06, 1e-07, and 1e-08.<\/p><p><\/p><p>Below are the results of those simulations:<\/p><\/p>\n

      \n
    1. Auto shutoff 1e-05:<\/li>\n<\/ol>\n

      <p><\/p><p>2. Auto shutoff 1e-06:<\/p><p><\/p><p>3. Auto shutoff 1e-07:<\/p><p><\/p><p>4. Auto shutoff 1e-08:<\/p><p><\/p><p>The number of gratings, transmission, and propagation orders are almost the same for the results from different mesh cells per wavelength.<\/p><p> <\/p><p>For the broadband spectrum, I am assuming that the distribution of the light source’s spectrum is normal, based on Guilin Sun’s explanation provided in the Ansys Forum.<\/p><p><\/p><p> <\/p><p>I also obtained the results for T and Ey from the sweep.<\/p><p><\/p><p>For mesh cells per wavelength, the results are the same from mesh 6 to 18.<\/p><p> <\/p><p> <\/p><p> <\/p><p>For the auto shutoff settings from 1e-05 to 1e-08, the results are slightly different for each parameter, as shown below:<\/p><p>a. T (lambda: 8e-07) and Ey (shutoff: 1e-05)<\/p><p><\/p><p>b. T (lambda: 6.4e-07) and Ey (shutoff: 1e-06)<\/p><p><\/p><p>c. T (lambda: 5.33e-07) and Ey (shutoff: 1e-07)<\/p><p><\/p><p>d. T (lambda: 4.571e-07) and Ey (shutoff: 1e-08) <\/p><p><\/p><p>e. Lambda 4e-07<\/p><p><\/p><p> <\/p><p>The results for T sometimes decrease and sometimes increase. Is this normal?<\/p><p>Regarding the Ey, some oscillations are present, but can we assume they indicate very high or poor results? (The simulation time was 1000fs, which is the default.)<\/p><p><\/p><p> <\/p><p>From these results, does my simulation seem convergent enough to you? Or is there anything concerning about the results or my settings?<\/p><p>Best regards,<\/p><p>Miller.<\/p><\/p>\n","protected":false},"template":"","class_list":["post-363356","reply","type-reply","status-publish","hentry"],"aioseo_notices":[],"acf":[],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/replies\/363356","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\/363356\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=363356"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}