Patent ID: 7450300
Filing Date: 2008-11-11
Classification: G02B,G03F

Abstract:
1. A high resolution objective lens assembly formed with refractive components that are substantially free from image-distorting intrinsic birefringence effects of a kind exhibited by calcium fluoride operating at 157 nm and cooperate to provide a high numerical aperture lens assembly operating with a specified deep ultraviolet wavelength of light carrying a subject image, comprising: first and second lens groups including optical components formed of high index of refraction lens element substrate material and cooperating to form a magnified, aberration-corrected image at an image plane, all of the optical components of the first and second lens groups formed of refractive lens materials; the first lens group including an aberration correction and compensation lens element positioned to receive nonconverging light rays of a specified wavelength, the light rays carrying a subject image; and the second lens group including a converging lens clement positioned to receive light rays propagating from the first lens group and converge the light rays carrying the subject image to form the magnified, aberration-corrected image at the image plane, the second lens group including a final lens element having a piano exit surface and a liquid interface film resident at the plano exit surface to provide for the lens assembly a numerical aperture of greater than 1.0.