I agree, this lens looks like a Fresnel lens taken to microscopic extremes:
the new fisheye lens consists of a single flat, millimeter-thin piece of glass covered on one side with tiny structures that precisely scatter incoming light to produce panoramic images
It’s not. The mechanism by which it acts is quite different. The lens is a metasurface lens, which has small structures that cause the phases of light to constructively or destructively interfere. The result is caused by the fact that, by carefully picking how light interferes, one can form an image on the other side of the lens. This differs from a Fresnel lens (or other classical lenses), which essentially form images by having rays of light which emerge from one spot, on one side of the lens, converge to another spot on the other side.
(In particular, wave theory is not needed to predict the behavior of classical lenses.)
>> this lens looks like a Fresnel lens taken to microscopic extremes:
Except I don't think it is. It's probably more like a diffraction grating or a hologram. You can actually make a flat lens by creating a hologram of a real lens and it will be flat.
Wavelength specificity. You only get the original focal depth at the wavelength you used to make the hologram, and it changes proportional to the wavelength. When you consider that blue light is 2/3 the wavelength of red light, you can see that this is chromatic aberrations big brother.
Diffractive elements are very wavelength dependent so while something like this would only work for monochromatic light (like a laser), but not for multiwavelength light. For that you would need to do some colordiversity.
the new fisheye lens consists of a single flat, millimeter-thin piece of glass covered on one side with tiny structures that precisely scatter incoming light to produce panoramic images