Development of new gradient index glasses for optical imaging systems.

摘要

Previous research has shown that many imaging systems can benefit from the use of gradient index (GRIN) materials. The required number of lens elements can often be reduced or the system performance can be improved. The use of gradient index lenses has not become widespread, however, largely due to three major problems. The first is that there is a lack of available gradient index materials. Lens designers require glasses with a wide range of refractive index and dispersions in both homogeneous and gradient index systems. Very few GRIN glasses have been developed and only small diameter (1-3 mm) gradient index rods are commercially available, leaving virtually nothing for the lens designer. The second problem is that adequate control of the index of refraction profile must be achieved. This is necessary in order to control the aberrations of the systems in question. The last problem is that the mathematical representation of the index of refraction profile is not currently linked to the fabrication parameters, thus making it difficult to manufacture a lens once it has been designed.;This work concentrates largely on the first of these problems. Several new glasses have been developed which are suitable for fabricating both axial and radial gradients by Ag;The usefulness of these glasses in optical systems is assessed and a procedure for designing lenses with manufacturable index profiles is also demonstrated.