本文通过对耦合棱镜中反射光束强度变化的测量，给出了平板波导的全部折射率参数，包括波导表面、波导模以及衬底的折射率，由此可以精确的得到平板波导的折射率分布，为波导的设计提供了可靠的参数.

In prism-waveguide coupling experiment we found that the reflected light through the prism carried all information of waveguide refractive indices. According to the intensity variation of the reflected light, the refractive indices of optical waveguide,including effective indices of waveguide modes and substrate index, can be measured precisely. Then the refractive indices at different depths can be determined by curve fitting.