The sampler doesn’t have any effect on close to 99% of the intensity of the input beam. This major component can be called the main beam that travels through it as if it was a regular Ar/Ar coated window. However the sampler deflects a small percentage of the intensity to higher order beams, i.e. it projects a copy of the beam at well-defined angles. Each copy takes a small portion of the input beam energy. The deflected beams take a fixed percentage of the power and have the same beam shape as the input beam.
Each of the 2 orders +1 and –1 contain the ratio mentioned in the selected products table. Other orders with useful energy maybe the +3 and –3 at an angle about 3 times as large as the 1st order. The portion of the energy in each of these orders is about 10% of that in the 1st orders, depending on the type. The element is highly wavelength dependent. For more details you can contact Holo/Or.
Figure 1: Conceptual lay-out of beam sampler.