Selection of coupling focal length for an elliptical beam
Determination of the effective coupling diameter
In order to find the best coupling focal length in case of an elliptical beam use the effective beam diameter Øeff which is calculated from the small and the large diameters Ø|| and Ø⊥ of the collimated elliptical laser beam:
Definition of the effective beam diameter Øeff.
Selection of focal length
After determining the effective beam diameter Øeff. The best focal length can be determined. This is done by replacing the diameter Øbeam with Øeff in the corresponding formula.
Measures to increase the coupling efficiency for elliptical beams
Coupling efficiency can be increased by converting the elliptical laser beam to a circular beam using anamorphic beam-shaping optics.