How do you distinguish between coherent and incoherent illumination simulations?
Lumerical’s optical solvers are based on Maxwell’s equations and are therefore fundamentally coherent. There are various ways to introduce incoherent effects, and are described here.
Below is a summary of how OpticStudio handles coherence in different modes:
Sequential – in general, coherence isn’t taken into account for basic sequential tracing, however we do have some analysis features which will model coherence. One of these is partially coherent image analysis, which allows the modeling of coherent, incoherent, or partially coherent systems. (http://www.zemax.com/os/resources/learn/knowledgebase/performing-partially-coherent-image-analysis)
POP – this is what we use for ZBF files. POP is a fully coherent simulation, and we don’t currently offer anyway to view the results incoherently. (http://www.zemax.com/os/resources/learn/knowledgebase/exploring-physical-optics-propagation-in-opticstud)
Non-sequential – in non-sequential mode, each ray that is traced keeps track of its phase, which can then be added either coherently or incoherently on a detector. If you choose to view the coherent data, each pixel will look only at the rays hitting it, and sum their phases independently from all of the other pixels.