The invention is directed to a method and an arrangement for high-resolution microscopic imaging in laser endoscopy based on laser-induced object reaction radiation and for performing microscopic cuts in biological tissue. In using multiphoton processes for endoscopic applications in biological materials with an accuracy of under one millimeter, radiation of a pulsed femtosecond laser is focused into an object by means of a transmission focusing optics unit comprising a transmission system and miniature focusing optics having a high numerical aperture greater than 0.55 to trigger a local object reaction radiation in the micrometer to nanometer range, and the distal end of the transmission focusing optics unit is moved in at least two dimensions for highly spatially resolved scanning of the object and for transmitting object reaction radiation which is scanned in a locally progressive manner to an image-generating system with a photon detector. In an other embodiment the femtosecond laser radiation is energy enhanced is applied to the same transmission focusing optics unit to perform microendoscopic surgery in biological tissue.
