Spectral separators & combiners are used for separating/combining different laser harmonics or different spectral ranges by transmitting one and reflecting the other. Such optics is produced with dichroic coatings which typically works at 45˚ angle of incidence and allow different response for particular spectral ranges.

Typical example could be a splitter for Nd:YAG laser application, which reflects the third harmonic at 355 nm, and transmits the first and the second at 1064 nm and 532 nm, respectively.

Separators & Combiners could be designed to work for average polarization, as well optimized for different polarizations or various incident angles in order to reach best results in specific applications.