Fluorinated dihydroxy phosphine oxide monomers were synthesized via chlorination, Grignard, and demethylation techniques. The prepared monomer was successfully polymerized with each of the three perfluorinated monomers (decafluoro-biphenyl, decafluorobenzophenone, and pentafluorophenylsulfide) by nucleophilic aromatic substitution. The average molecular weight ranged between 7800 and 14,900 g/mol. The glass-transition temperatures of the polymers were registered in the range of 185-235 degreesC, and all the polymers exhibited high thermal stability up to 326-408 degreesC. The results of the refractive-index measurements indicated control of the refractive index between 1.5181 and 1.5536 and an optical loss of 0.53 dB/cm at 1550 nm. (C) 2003 Wiley Periodicals,