A super-luminescent light emitting diode (SLED) operating around 1300nm is simulated. This edge-emitting device is grown on an InP substrate and comprises multiple quantum wells. For the simulation the focus is put on the amplified spontaneous emission (ASE) spectra for different input currents as well as on the output power vs. current curves (light vs. current---LI). Simulated ASE spectra agree very well with measurements over a large wavelength range (more than 80nm). Regarding the LI-characteristics good agreement between simulations and measurements is obtained for input currents from 10mA up to 150mA. The simulated electrical characteristics of the device are obtained by solving drift-diffusion equations, the optical problem is solved by decomposing the vectorial (3D) Helmholtz equation into a transverse and into a longitudinal part.