1. An optical probe able to induce at least one of fluorescence light, reflectance light and Raman scattering in vivo in a target tissue, the optical probe comprising a proximal end, a distal end, at least one light emitting diode disposed at the distal end of the optical probe and operatively connected to a power source able to provide power to the light emitting diode such that the light emitting diode can emit excitation light able to induce at least one of fluorescence light, reflectance light and Raman scattering in the target tissue, and at least one collection fiber that transmits light from the distal end of the optical probe to the proximal end of the optical probe, the distal end of the optical probe comprising at least one of a plurality of light emitting diodes that emit different wavelengths of excitation light and a plurality of light filters that transmit different wavelengths of excitation light to provide a plurality of light sources, and an on and off switch to switch the light emitting diodes on and off such that the target tissue is illuminated sequentially by one of the light sources at a time.