A micro Fresnel tens1,2 is a useful device for optical pickup and laser printer heads because of its small structure, light weight, high diffraction efficiency, and diffraction-limited focusing characteristics. A micro-Fresnel lens fabricated by electron-beam (EB) lithography3 has achieved high diffraction efficiency (65%). A collimated laser light source has been produced using the micro-Fresnel lens. However, the lens replicating technique necessary for practical use of the lens has not been established. Photopolymerization (2P) Is the conventional method. Replica lenses fabricated by the 2P method have poor temperature and humidity characteristics because the lens material is polymeric, furthermore lack of a lens pattern is caused by air vesicles.
© 1989 Optical Society of AmericaPDF Article