Clamping glass

The pressure tool from the top must not only exert the necessary force on the weld seam, but also allow the laser to pass through.
Ideal is the pressing with a clamping glass, because it does not obstruct the laser beam nor the heat radiation for pyrometry.

However, if the upper part has protrusions, a flat glass plate can no longer be applied. A possible solution is a mechanically machined clamping glass.
As such a machined glass is relatively expensive and tricky because of possible breakouts of the glass edges. An alternative solution is to insert a machined acrylic glass as an intermediate plate between the upper part and the clamping glass.