What is all the fuss about diffractive optics? Why the diffractive lenses are deemed so resourceful? They may not be more than Fresnel lenses entailing smaller features. You may wonder about the magic they create. Let us delve on it.
Diffractive elements are best described as a thin phase element operating through interference and diffraction. It would help produce random distribution of light or help in designing of the optical systems. You should rest assured that diffractive optics is not magic. They are just another important tool used for designing the optical system. They could do various kinds of things that refractive optics may be unable to produce. Moreover, diffractive optics is relatively light in weight and smaller than refractive optics.
You should remember that the benefits of a diffractive optical element would not be free of charge. The diffractive optical element or DOE would work under certain restrictions. They would be tough to produce and provide the desired results under specific conditions only. For instance, if you were looking forward to producing a circular laser beam having a uniform intensity profile, you would make use of a refractive expander to expand the beam. It would mask everything without hampering the center of the beam. You would receive a uniform beam but may waste plenty of light.
You may also have the option of choosing a relatively complicated refractive design inclusive of a micro lens array. It would be relatively difficult to engineer along with producing undesired results. Nonetheless, you would have a decent job at your hands under various kinds of conditions. The intensity of the beam could be made uniform over a large distance. It would not be wrong to suggest that the input beam to the micro lens array does not need to be parallel. It would work decently across the broad range wavelength.
You would be able to design the DOE beam shaper for providing any intensity profile. Nonetheless, it may not be easier to produce. It may bring forth specific drawbacks of DOEs. Despite being very sensitive to errors, you may be able to produce the desired intensity profile over a small distance.
When you consider diffractive optics as mere Fresnel lens entailing smaller features, you should rest assured it is imperative to gain knowledge about the Fresnel lens is a diffractive optic. When you have an in-depth understanding of diffraction, you would realize that all lenses are diffractive optics. You could also design one producing a simple focal point. It would result in simple lens design.