Based on the measurement of dispersion characteristic and birefractive index of the fluorinated polyimide film, a statistical optimum design method is proposed and used to realize the design of 32- and 36-wavelengths optical waveguide wavelength - interleave coupler (i, e., interleaver) with the optimization of polarization fluctuation and wavelength interval of 0. 8 nm at 1 550 nm. The largest cross coupling ratios of the two interleavers are respectively less than 1. 8% and 3. 5%, while the least through coupling ratios are respectively greater than 98.2% and 96.5%. The output differences due to polarization fluctuation are less than ±1.7% and ±3.2%.