Microtomy with femtosecond lasers

A laser microtome comprised of a femtosecond laser source that emits light in the near-infrared range, enabling contact-free cutting of tissues. The near-infrared range is better suited for processing biological material, as most of the biological tissues have a significantly low absorption coefficient in the infrared part of the spectrum. The laser beam is tightly focused into the specimen by a high-numerical-aperture object, to cut the biological tissue. These tightly focused intensities of the laser beams lead to ionization of the illuminated material by multiphoton absorption and formation of a plasma. Mechanical and thermal side effects are reduced, limiting the range of collateral damage to diameters below 1 μm, due to low energy deposition into the tissue. The main component of a laser microtome is a high-power femtosecond oscillator, emitting ultrashort laser pulses, with a wavelength of 1030 nm.