Patent Number: 050420593
Section: abstract

Optical elements for radiation comprising a graphite film obtained from a film of a polymer such as polyphenylene oxadiazole, polybenzothiazole, polybenzobisthiazole, polybenzooxazole, polybenzobisoxazole, polypyromellitimide, polyphenylene isophthalamide, polyphenylene benzoimidazole, polyphenylene benzobisimidazole, polythiazole or poly-p-phenylene-vinylene. The graphite film is obtained by pyrolysis of the polymer film at 2800.degree. C. or higher at a pressure of not lower than 4 kg/cm.sup.2 in vacuum or in an inert gas. Alternatively, the element may be made of a graphite film obtained from the polymers mentioned above and intercalated with a metal halide. The intercalated films are readily bonded by pressing in the form of a thick sheet or block. Still alternatively, the graphite films and the intercalated films may be superposed alternately and bonded by pressing, or the intercalated films may be sandwiched between the graphite films and bonded together to form a thick sheet or block. The optical element has application as a lens, monochromater, filter or analyzer for radiations.