Light delivery by fiber can directly excite the desired region. In recent years a number of methods have been proposed for fiber-based multiphoton microscopy. Of particular interest is the type of fiber used for both excitation with femtosecond pulses and method of collection of emitted fluorescence. In our efforts towards the development of a compact multiphoton microendoscope, we have conducted a study comparing the performance of three types of fibers (single mode fiber, hollow core photonic crystal fiber, and double clad fiber) in order to provide an objective comparison between various excitation approaches. In this study, we have demonstrated the ability of multiphoton microscopy and second harmonic generation microscopy for high resolution intensity and life time imaging of the oral mucosa and submucosa in vivo based on the use of double clad photonic crystal fiber.