In this study, we have simulated the effect of light sources with different spectral output functions on the generation of A-scans in optical coherence tomography using a fundamental physics-based interferometric model. Many different source function were examined, and compared to a standard Gaussian source. These sources included truncated Gaussians, multiple Gaussians, other non-Gaussian, Lorentzian, square and triangular sources. Only the pure Gaussian source produced A-scans without false artefacts such as satellite peaks, that could produce misinterpretation of real OCT images that may be used for patient diagnosis. A triangular source produces the next best response with small extraneous peaks, whereas all other sources have significant false artefacts present in their A-scans.