Abstract: An optical fiber with low attenuation of light transmission comprising a core and a cladding, wherein the core is made of a polymer comprising units of deuterated methyl methacrylate containing 10 to 40% of a methacrylic ester the ester moiety of which has an alicyclic hydrocarbon group of from 6 to 20 carbon atoms, and the cladding is made of a transparent polymeric material having a refractive index of at least 3% smaller than that of the core, which optical fiber has excellent heat and humidity resistance as well as good flexibility.

Abstract: A plastic optical cable comprising a core, a cladding layer and a protective layer made of an ester type thermoplastic elastomer, which has low degree of thermal shrinkage and low attenuation of light transmission even at high temperature.

Abstract: A plastic optical fiber comprising a core and a cladding, wherein the core is made a polymer comprising units of methyl methacrylate and of a methacrylate ester, the ester moiety of which has an alicyclic hydrocarbon of 8 to 20 carbon atoms, and the cladding is made of a fluorine-containing polymer comprising units of the formula: ##STR1## wherein R.sub.1 and R.sub.2 are each hydrogen or C.sub.1 -C.sub.3 alkyl, R.sub.f1 is fluorine or trifluoromethyl, an R.sub.f2 is C.sub.2 -C.sub.10 fluoroalkyl, which units (I) are derived from fluoroalkyl .alpha.-fluoroacrylate or trifluoromethacrylate, which has short- and long-time heat and humidity resistance as well as low attenuation of light transmission.