Analysis of abrupt bent waveguides by the beam propagation method and the conformal mapping method

In this study, we propose a simple and applicable approach to analyze the large angle (larger than 100) abrupt bent waveguides. By using the conformal mapping technique, the abrupt bent waveguide is transformed into an equivalent straight one which the conventional (paraxial) beam propagation method (BPM) can be applied to analyze it directly. The field distribution in a 20/spl deg/ microprism type abrupt bent waveguide is also demonstrated by our method.