Polymer clad quartz optical fiber cord
 A polymer clad quartz optical fiber cord comprising a core of quartz glass, a clad of an organic polymer surrounding said core, a protective layer surrounding said clad and a covering layer surrounding said protective layer, and an organic polymeric tension fiber disposed between said protective layer and said covering layer characterized in that the cross-sectional structure of said cord satisfies the following formula: ##EQU1## where D3 represents the outer diameter (in mm) of said protective layer, D4 represents the inner diameter (in mm) of the covering layer, d represents the denier number of the tension fiber and is an integer from 1,000 to 5,000, and .rho. represents the relative density of the tension fiber. 
Toray Industries, Inc.
G G
G02B G02B
inventional inventional
Masanori Hidekazu
Takeuchi Kunieda