offset / halo issues driving me mad ...

[bloq]

Hey,

i keep struggling with several issues with my laser. Today i tried to engrave an anodised alumium and acrylic. I noticed there is some kind of halo
on the left side of my object. (Please find pictures attached). I tried several positions for the laser head but it did not change a bit. I am not sure if this
is an optics issue or where to look for it. I tried a hundred different speed settings but none helped. If i keep the engraving on acrylic more shallow
the problem is barely visible but more power always leads to this.

thank you so much for any idea
tm