A single wavelength V-coating will provide reflectance less than 0.25% for 0° incidence or 0.5% for 45° incidence at the chosen wavelength. Dual wavelength coatings will approach the performance of V-coats for two selected wavelengths. They are useful for optics which must transmit a visible alignment laser as well as a near IR process beam or for transmission of fundamental and first harmonic wavelengths.

Dual wavelength AR coating allows two center wavelengths radiation pass through the substrate with high transmission. This coating is often used in frequency doubling systems or the other muti-laser output systems, as the Nd: YVO4 laser (1064nm) and its second harmonic generation (532nm) green laser.