Abstract: An efficient method has proposed for evaluating the splice loss between two nonidentical arbitrarily graded-index singlemode planar optical waveguides.The power transmission coefficients are expressed as the sum of Hermite-Gaussian functions, and then the overlap integrals can be calculated analytically. Numerical examples have been given and the influence of waveguide parameters and the individual misalignment on splice loss is discussed. We have checked the accuracy of approximating the load due to both defects by adding the losses due to each individual defect.

Key words: planar optical waveguide, splice loss, overlap integral