Beamsplitter coatings are available with a choice of wavelengths corresponding to each of the harmonics of the Nd:YAG (1064nm, 532nm, 355nm, 266nm) and optimized for equal 50/50 (R/T) split of P- or S- polarization. A V-coat antireflection coating optimized for 45° angle of incidence beams is applied on the back surface to minimize ghost reflections.

UV Grade Fused Silica is synthetic amorphous silicon dioxide of extremely high purity providing maximum transmission from 195 to 2100 nm. This non-crystalline, colorless silica glass combines a very low thermal expansion coefficient with good optical qualities and excellent transmittance in the ultraviolet region. Transmission and homogeneity exceed those of crystalline quartz without the problems of orientation and temperature instability inherent in the crystalline form. It will not fluoresce under UV light and is resistant to radiation. For high-energy applications, the extreme purity of fused silica eliminates microscopic defect sites that could lead to laser damage.

Optics with perfectly parallel faces are unsuited for use as reference elements in laser setups as reflections from both surfaces would be collinear resulting in undesired large period fringes. The introduction of a slight wedge causes unwanted reflections from the second surface to be deflected from the optical path. The back surface (S2) of these beam samplers is slightly wedged and an arrow on the side points to the non-wedged side (S1).

High fluence Nd:YAG lasers may be used safely with these splitters. Extra durable multilayer coatings are used for both the front beamsplitting surface, and the AR-coated back surface. This results in typical damage threshold at 1064nm of 5 MW/cm² for CW, 5 J/cm² for 0.1–100 nsec pulses. Typical damage threshold at 532nm is 2.5 MW/cm² for CW, 2.5 J/cm² for 0.1–100 nsec pulses.

Reflection and transmission at wavelengths other than the specified wavelengths are uncontrolled and can vary significantly from the curve shown. Use of beamsplitters outside the design wavelengths is not recommended.