A Comparison of Confocal and Two-Photon Microendoscopy

Within this paper a microscopic probe for use in confocal and two-photon microendoscopy is proposed. This miniaturized probe simply consists of a fiber bundle and an adapted custom-made micro-optical system. In addition the overall setup used permits to switch between different linear and nonlinear laser sources for this probe leading to directly comparable images of any sample. First preliminary results show, that for fiber based systems two-photon excitation of exogenously applied fluorescent contrast agents is not only favorable due to the greater penetration depth in tissue and the possible integral signal detection, yet also because of improved axial resolution using real life optical systems.