{"id":382551,"date":"2024-09-12T22:07:02","date_gmt":"2024-09-12T22:07:02","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/far-field-projection-of-gaussian-beam\/"},"modified":"2024-09-12T22:07:02","modified_gmt":"2024-09-12T22:07:02","slug":"far-field-projection-of-gaussian-beam","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/far-field-projection-of-gaussian-beam\/","title":{"rendered":"far field projection of gaussian beam"},"content":{"rendered":"

<p>I’m trying to understand the far field projection of a gaussian source with NA=0.1. I calculated the far field projection from fields measured on a 2d monitor that is normal to the propagation direction. With the ‘thin lens’ option, there is a hole at the center of the beam. Is this expected\/correct? if so, why? Given that my wavelength~1 um and beam waist ~3 um, I thought I should use ‘thin lens’. I also tried applying the ‘scalar approximation’. The resulting beam cross section is qualitatively different, and more like what I expected. Does it mean I should use salar approx for this beam? Previously I also did some scattering\/force calculations using the E- and H-fields from monitors; those results are at lease qualitatively similar regardless of how I configured the gaussian source.<\/p><p>\"\"<\/p><p>\"\"<\/p><\/p>\n","protected":false},"template":"","class_list":["post-382551","topic","type-topic","status-publish","hentry","topic-tag-gaussianbeam-1","topic-tag-fdtd"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t