Limitations

The Fourier grating concept works best for low order gratings. If the grating is required to only produce a number of high diffraction orders, the phase structure within the unit cell oscillates very fast, and a large number of Fourier coefficients is required to model it. This makes it difficult to optimize and to manufacture the gratings. However, this is a fundamental limitation and is shared with other grating types like the Dammann grating.