We discussed the analysis procedure of planar optical waveguide devices using the pseudo-spectral time domain(PSTD) method.The uni-anisotropic perfectly matched layer(UPML) has been introduced into the PSTD method.A compact twin wave sources has been used to excite the guided wave devices.Utilizing these techniques in this work,a distributed feedback grating has been simulated.The result shows good agreement with the traditional finite difference time domain(FDTD) method,moreover this work shows much higher efficiency in computational requirements.