They can be fabricated in a wide range of materials viz. DOEs have enabled the development of some products that could not be produced with previous optical technologies. The focal length and aberration characteristics of a diffractive element vary with wavelength. Several different optical elements can share the same substrate without interfering with one another. Thus, a single DOE can be used as a lens, beam splitter and spectral filter simultaneously.
Diffractive elements are very light, as they are formed in thin films of a few um thickness only.
Because DOEs can generate unique optical functions that are not possible by conventional reflective or refractive optical elements, they provide greater flexibility in system configuration. At least one surface of a conventional glass lens is curved, whereas for a diffractive lens there is no such requirement. A diffractive element can be fabricated on any arbitrary shape of the substrate. They can be made to operate over a narrow wavelength band. The fabrication and replication of DOEs are relatively easy and cheap because no precision shaping of a surface is required.