Benchmark tests and modelling tasks

In this chapter we describe benchmark tests and modelling tasks to mutually compare the performance of various beam propagation methods and other software developed and/or currently in use in various laboratories. Two sets of tasks for testing the behaviour of beam propagation methods applied to both lossless and lossy (absorbing) waveguide structures are described in the next section. Theoretical background required to understand the latter task is presented in Section 3.2. Then, an important problem of modelling light propagation in waveguide tapers, both symmetric and asymmetric, is discussed in Section 3.3. Comparative modelling of an example of optical waveguide devices containing thin metal films that can support propagation of surface plasmon waves is described in Section 3.4. In the last section, results of truly bi-directional modelling of light propagation in a very deeply etched Bragg waveguide grating filter are presented. The work described in this chapter was organised within the framework of the Action COST 240.