Simulation of electromagnetic waves is increasingly driving innovation in R&D of laser optical and 5G systems. Depending on the ratio of device size/wavelength, excitation and material COMSOL offers solutions that approach every problem as efficiently as possible. Beyond the classical frequency domain method, the beam-envelope method is used to efficiently calculate propagation along fibers across large distances. Alternatively, the boundary-elements method can be used to simulate 5G scattering field interaction across large omnidirectional distances. Finally, the propagation of optical pulses can be simulated and resolved in time using the transient or time explicit method, completing the holistic optics simulation tool set.