| 摘要 |
<p>An optical element (140) having an optical axis (152) with front and rear surfaces (142, 144), and comprising a plurality of definable adjacent zones of optical material, each zone having a definable refractive index different from the refractive index of an adjacent zone and an Abbe number, the zones of optical materials being arranged parallel to each other to define a profile of refractive indices which is symmetric about a plane of symmetry along the optical axis (150) of the element (140) and parallel to the zones. In one embodiment the optical element is a spectrally invariant lens.</p> |
