Ln. Arkhipova, NEW OBJECTIVE SYSTEMS BASED ON GRADIENT-INDEX MATERIALS AND COMPONENTS WITH INTERNAL ASPHERICS, Journal of optical technology, 61(8), 1994, pp. 628-630
This paper discusses several versions of objectives with a diameter up
to 3 mm, either based on a material with a radial refractive-index di
stribution or using modules that consist of pairs of glasses separated
by an aspheric surface. The resulting lenses are recommended as objec
tives for endoscopy and other purposes.