Summary form only given. Optical coherence tomography (OCT) has proven over the past few years to be a powerful new optical imaging modality. OCT uses interferometric detection and a short-coherence-length light source to achieve high sensitivity, high-dynamic range, and high resolution (1-10 /spl mu/m). Biomedical applications include ophthalmology, microscopy, endoscopy, laproscopy, dermatology, developmental biology, dentistry etc. One of the key components in OCT systems is the optical source. This paper presents preliminary results on the use of spectrally flattened rare-earth-doped fiber ASE source in OCT systems. Rare-earth-doped fibers are a very promising candidate for future OCT systems. The authors expect spectrally shaped rare earth-doped fiber ASE sources to play an important role in future OCT systems. In the near future, source powers in excess of 100 mW and coherence lengths under 10 cm should be available at a variety of wavelengths. The authors review some of the design details on this Nd source, quantify its optical parameters power, bandwidth, blindness, etc.), and present its application in tomographic biomedical imaging (e.g. skin and bone structure). The authors also compare its performance with other types of sources such as: semiconductor sources (light-emitting diodes, edge-emitting diodes, superluminescent diodes), model-lock lasers, and supercontinuum sources.