{"id":162362,"date":"2021-09-18T13:38:44","date_gmt":"2021-09-18T13:38:44","guid":{"rendered":"\/forum\/forums\/topic\/2d-gc-inverse-design-lumerical-example\/"},"modified":"2021-09-27T22:17:29","modified_gmt":"2021-09-27T22:17:29","slug":"2d-gc-inverse-design-lumerical-example","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/2d-gc-inverse-design-lumerical-example\/","title":{"rendered":"2D GC Inverse Design Lumerical Example"},"content":{"rendered":"
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I wanted to use the inverse design provided by Lumerical. I downloaded the example for the 2D grating coupler but I was unable to run it properly such that I get the results posted on their source website. According to the online guide I should just hit the run button and get the same\/similar result as they have presented on the website. Unfortunately, I get the following message:<\/p>\n

ABNORMAL_TERMINATION_IN_LNSRCH<\/p>\n

 Line search cannot locate an adequate point after 20 function<\/p>\n

 and gradient evaluations. Previous x, f and g restored.<\/p>\n

 Possible causes: 1 error in function or gradient evaluation;<\/p>\n

         2 rounding error dominate computation.<\/p>\n

<\/p>\n<\/p>\n

I have added the log output from the optimization. I do not understand what problem causes this termination. It indicates, that the optimizing function is too flat for a gradient to be found, how could I resolve this? Maybe the bounds are too small?<\/p>\n

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\nLogOutput_InverseDesign.txt
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