A Fast Method to Calculate Output Energy of a Single Mode Waveguide and Its Application to Optimization of Structure
一种计算单模波导输出的快速方法及其在结构优化中的应用

A new method that can be used when coupled intensity is desired for an output waveguide is presented.One way to obtain coupled intensity is to calculate the field via beam propagation method(BPM).Another method is the overlap integral method,which is only for an unvaried waveguide.The new method combines BPM with overlapping integral method and overcomes disadvantages of both methods.It is called orthogonal filtering method.In the last section,as an example,this method is used to optimize the taper shape for on output waveguide of a star coupler.