Ultrafast lasers have become a promising tool for micromachining and extremely precise ablation of all kinds of materials. Due to the low energythreshold, thermal and mechanical side effects are limited to the sub 1m range. The neglection of side effects enables the use of ultrashort laser pulses in a broad field of medical applications. Moreover, the interaction process based on nonlinear absorption offers the opportunity to process transparent tissue three dimensionally inside the bulk. We demonstrate the feasibility of surgical procedures in different fields of medical interest: In ophthalmology intrastromal cutting and preparing of cornael flaps for refractive surgery in living animals is presented. Besides, the very low mechanical side effects enables the use of fs-laser in otoralyngology to treat ocecular bones. Moreover, the precise cutting quality can be used in fields of cardiovascular surgery for the treatment of arteriosklerosis as well as in dentistry to remove caries from dental hard tissue.

No abstract

No abstract

Usually, sectioning of biological specimens is performed by mechanically operating microtomes. In order to process a tissue sample, a range of pretreatments such as fixation, dehydration, and embedding in resin or paraffin, or freezing are needed. These treatments can cause alterations inside the biological material, which may lead to artifacts. A laser microtome is a new sectioning device, which cuts tissue or other material with the help of photons instead of steel blades. The method is contact free and enables tissue to be cut in its native state. Special preparation techniques are not required.

The laser microtome (LMT) is designed to slice biological tissue and various materials with high precision. The cutting process is performed by an ultrafast laser, emitting infrared light with high repetition rate of about 10 MHz. Biological Tissue can be sliced without fixation and embedding. Therefore cutting of native tissue is possible. Due to the non contact procedure further investigations of the material like immuno histological tests can be performed. At present slices with a thickness of 5 − 100µm in different biological tissues like cartilage, kidney, lung and cornea has been shown. In conjunction with a 3D imaging system like optical coherence tomography, preparation of 3D tissue volumes is possible too.