This project investigates methods to model and simulate nanoscale light emitters in complex environments. Semiconductor quantum dots can be used as light sources in quantum information processing. Typical applications like secure communication or quantum-computing require integration of quantum dots into optical nanostructures. For the analysis and design of such structures and their interaction with radiation emitted by the quantum dots, numerical modeling and simulations are essential. In this project we concentrate on the specific problems arising when pointlike sources like quantum dots are interacting with nanostructures which support optical resonances. We plan to develop, extend and analyze methods for efficiently simulating coupling to optical resonators with material dispersion and for handling complex 3D setups like e.g. in the case of coupled resonators.