Methods and devices for an optical assembly for a laser generator comprise: a laser source producing a first beam of light and an optical assembly. The optical assembly comprises a prism. The prism has a bottom surface configured to receive a first beam at an incoming angle of incidence relative to a first surface normal, and a hypotenuse surface configured to transmit, at an exit angle relative to a second surface normal, a second beam having a second aspect ratio. The optical assembly further comprises a plano-convex lens configured to transmit the second beam to a coupler. The coupler comprises a first coupling plane at a first distance from the plano-convex lens and a second coupling plane at a second distance from the plano-convex lens. The combination of the prism and the plano-convex lens is configured to change the beam divergence, so that the first coupling plane has a third aspect ratio and the second coupling plane has a fourth aspect ratio.
