Systems and methods for imaging ear tissue include: directing illumination radiation to pass through an intact biological structure and be incident on ear tissue that does not include an exogenous fluorophore, at a plurality of locations, the illumination radiation including a plurality of light pulses each having a temporal duration of 500 femtoseconds or less; for each one of the plurality of locations, using a detector to detect radiation emitted from the location that passes through the intact biological structure; and forming an image of the tissue based on the detected radiation at each of the plurality of locations, where the emitted radiation corresponds to endogenous two-photon fluorescence of the tissue.