If the non-sequential mode has been used recently, on the light source, select LD light source, with relevant parameter settings (in the lens data editor). If sequential mode is used, paraxial Gaussian beam analysis, that is, physical optical analysis, is needed. Its related parameter settings can be set in Analysis/Physical Optics/Paraxial Gaussian Beam Analysis (shortcut key Ctrl+B), but this function may only be available in zemax ee version.
I just started to learn, and I don't know much about it. Please give me some advice.