Beam combiners are partial reflectors that combine two or more wavelengths of light– one in transmission and one in reflection– onto a single beam path. Since the 10.6 micron laser is invisible, in the actualprocess of laser marking, we often need to know where the focus of the laser is, so as to determine if the position of markingis correct or not. By the beam combiner,we combine the red light of the visible 650nm emitted by the diode with the 10.6 micron laser into one beam of light, so thatwhere the 650nm red light is pointing is the position of 10.6 micron laser, thus achieving the purpose of using the red light of 650nm to indicate the 10.6 micron laser
