一种新的基于最小平方逼近的广角光束传播方法

A new beam propagation method based on least-squares expansion approximating

用最小平方逼近展开传播算子 ,实现了一种新的半矢量显式高阶有限差分光束传播方法 .这种方法中不需要选择参考折射率 ,并在整个传播常数 (包括辐射模的传播常数 )分布区域进行逼近 ,解决了在泰勒展开和庞德逼近中存在的参考折射率选择和远离展开点误差增大等问题 .用这种方法对几种典型波导结构进行了数值模拟 ,模拟结果验证了算法的正确性和可靠性 .

A new finite difference wide-angle beam propagation method is developed by introducing the least-squares expansion approximant in the propagator expansion. In this new method it is not necessary to select the reference index point because of the whole region approaching the lease-square expansion. This method avoids the problems induced by error selection of the reference index in the old methods based on Taylor or Pade expansion. Several typical structures are simulated by the new method and the results prove the validity of it.