US Patent 11389241 Alignment method and tools

A laser system includes a first cavity to output a laser light along a first path, a first mirror to receive the laser light from the first cavity, and redirect the laser light along a second path that is different than the first path, a beam splitter removably located at a first position on the second path, a beam combiner removably located at a second position on the second path, and an alignment device having first and second alignment features. The first and second alignment features occupy the first position and the second position, respectively, on the second path, when the beam splitter and the beam combiner are removed from the first position and the second position.