Modeling of insertion loss of fiber Fabry-Perot filter with a bidirectional beam propagation method

Insertion loss caused by diffraction effects may yield low throughput in the Fabry-Perot tunable filter. A bidirectional beam propagation method (BPM) is introduced to describe the relationship between the related parameters such as length of air gap and mirror reflectivity and the insertion loss of fiber Fabry-Perot filter. The numerical simulation results indicate that the method can provide a simple and useful way for the device design.