Figure 1
Diffraction of a radiation beam that strikes the inclined surfaces of the grooves of a diffraction grating with periodicity p with an angle of grazing incidence γ. The trajectory of the incident beam is parallel to the grooves and the diffraction takes place off-plane. Then the incident beam at a position angle α and all diffracted orders are found on cones with identical opening angle γ. The specularly reflected beam from the grating surface will be found at position angle −α. The grating inclination with respect to the vertical plane is approximately drawn such that the diffracted beam at position angle β progresses in the horizontal direction. The diffraction will take place at blaze maximum when β = α = δ, where δ is the grating blaze angle as shown in the inset at the bottom. |