Apparatus for focus beam analysis of high power lasers

An apparatus for focus beam analysis of a high power laser, comprising:

• an optical wedge prism disposed between a laser beam source and a process focusing lens;
• said process focusing lens disposed between said optical wedge prism and a workpiece;
• said optical wedge prism oriented so that it offsets a laser beam from a laser beam source axis by a few degrees;
• said process focusing lens being tilted so that it is normal to said offset laser beam, thereby compensating for the few degrees of offset caused by said optical wedge prism;
• a second surface of said process focusing lens reflecting less than one percent up to about five percent (<1 to 5%) of said laser beam to said laser beam source;
• said reflected percentage of said laser beam being incident upon a second surface of said optical wedge prism;
• a pixelated detector disposed in light-receiving alignment with said second surface of said optical wedge prism, said pixelated detector measuring said reflected percentage of said laser beam;
• said second surface of said process focusing lens reflecting less than one percent up to about five percent (<1 to 5%) of said laser beam to said laser beam source so that said less than one percent up to about five percent (<1 to 5%) of said laser beam reverses its original path through said process focusing lens to said workpiece such that the lens power is the equivalent of two process focusing lenses;
• whereby back-reflected light from the second surface of the process focusing lens is focused onto said pixelated detector in order to monitor the amount of contamination accumulating on said process focusing lens as work is performed on said workpiece.