This book focuses on the instrumentation aspect of biomedical imaging with the use of optical fiber probes across three different disciplines. This includes the design and development of novel fiber optic based techniques and instruments in fields of optical coherence tomography (OCT), bioremediation and optical mapping of cardiac action potentials. A prototype all-fiber OCT system was subsequently constructed to meet the design requirements of combined fluorescence-OCT probes. A novel spectroscopic technique that can monitor bacterial species in-situ was developed. Its capabilities and limitations were demonstrated through a series of laboratory controlled experiments which showed promising preliminary results. A fluorescence setup was developed to make spectroscopic measurement of cardiac action potentials. This technique offered more insights into the complex process of spectral modulation which is usually associated with membrane potential and mechanical activity.