Two types of polymer ridge optical waveguide are prepared using new fluorinated polyimides with excellent transparency and refractive index controllability. One has a polyimide core with a refractive index n of 1.573 and an SiO/sub 2/ undercladding layer. The other has a polyimide core (n=1.521) and a polyimide undercladding layer (n=1.520). These waveguides exhibit a low loss of 0.3 dB/cm at 1.3 mu m. In addition, they have high thermal stability because of high temperature curing (above 350 degrees C).<<ETX>>