Schematic top-down view of a Bragg grating as an optical component and its effect on a beam. A collimated input beam with a flat spectrum enters the Bragg grating from the left. The grating diffracts the beam into the zeroth and first orders transmission orders. Inside the Bragg grating the refractive index modulation is visualized by the black and white stripes. The Bragg angle θ_B, grating thickness d, and grating pitch σ are also visualized. Based on Fig. 2 from Haffert et al. (2019b).