Hello, I made a 2D model for a single slit diffraction using EM waves and frequency domain. There seems to be some irregularity in the planar wave before the slit. Is this due to some reflection that I am not aware of or is it interference from the many source points along the bottom boundary?
https://www.youtube.com/watch?v=XnT45kzu53c This is the video I was basing my work off of and they seem to have a similar problem.