Recent Updates to the Optical Propagation Code OPC

In order to understand and design free-electron lasers (FELs), simulation codes modeling the interaction of electrons with a co-propagating optical field in the magnetic field of an undulator are essential. However, propagation of the optical field outside the undulator is equally important for evaluation of the optical field at the location of the application or to model FEL oscillators.
The optical propagation code OPC provides such capabilities and can interface with FEL gain codes like GENESIS 1.3, MEDUSA and MINERVA. Here we present recent additions and modifications to the code that improves the speed of the code and extends the modeling capabilities. These include amongst other, inline diagnostics that results in considerable faster runtimes, the ability to convert from free-space modes to guided modes (currently only cylindrical waveguides), and the possibility to determine the spectrum at each transverse location. The latter opens the possibility to include dispersion in the optical propagation.