Variable Attenuators (VA) enable a continuous variation of laser energy in a range of two or four orders of magnitude by tilding dielectric edge filters from AOI 0° to 45°without change of beam quality.
Beam displacement can be compensated by using Variable Attenuators and Inversely Variable Attenuators a second plate or two filters simultaneously.
Inversely Variable Attenuators (IVA) reflect the laser wavelength at normal incidence and have their full transmissionat ± 40°.
IVA's have higher damage thresholds and better thermal stability than VA's. Due to a flat characteristic of the 50% coatings, attenuation is more sensitive.
All Attenuators have an antireflection coating on the second side, ensuring highest transmission.