Abstract: A fiber optical cable is designed for good thermal stability over a broad temperature range and with low flame-spreading and low smoke-producing characteristics for interior use, such as in plenum areas. Optical fibers are each buffered with a layer of resilient polymeric material with a broad dynamic temperature range. A nonburning serving shields the buffer layer from flame, and a jacket of polymeric material surrounds the serving. The jacketed cables are bundled with a like number of strength members formed of a material with a coefficient of thermal expansion roughly matched to that of the optical fibers. The strength members and jacketed fibers are wrapped in tape, and the bundled components are tightly jacketed by a tube of polymeric material. The jackets and outer tube are formed of low flame-spreading, low smoke-producing fluorocarbons, whereby the cable meets U.S. requirements for plenum use.