Fabrication and Testing of the Nova 77 cm F/4 Focus Lens

Abstract

As the optical industry is changing, based on the demands of our ever moving technology and responding to these new requirements, innovation and the development of greater control and entirely new fabrication and test techniques are necessary for any successful organization. Optical fabrication techniques formerly left entirely to the skill and personal innovation of the optical craftsman are now moving away from traditional practices and are getting more engineering attention than ever before. The emergence of readily available electronic technology in convenient numerical control devices and the use of the laser as a light-source in test applications, have brought about an, as yet slow, but definite revolution. This does not by any means curtail the role of the optical craftsman, quite to the contrary, he now has at his disposal more control and more metrology to better apply his masterly skills to achieve the sophisticated accuracy demands imposed so routinely on our industry today. Aspheric surfaces, only a few years ago, applied refractively only in illumination systems, are now moving rapidly into universal optical applications. Designers are enjoying more freedom in being able to utilize this tool with the confidence that the more sophisticated optic they design can indeed be manufactured. The application presented here is an attempt to show current manufacturing approaches for a high accuracy single element aspheric focus lens for the LLNL laser fusion program.