Abstract: A method and system for making a three dimensional product wherein the size and shape of a plurality of cross-sectional segments of the three dimensional object are determined which when assembled together in a particular sequence form the desired three dimensional shape. Thin layers of material in the shape of each of the cross-sectional segments are applied in the particular sequence in which they form the three dimensional object. The application of each of the layers is much like a lithographic printing process in that a resin may be applied by a roller in the shape of the cross-sectional segments.

Abstract: A medical treatment laser is disclosed that minimizes absorption of laser energy along the beam path by using a lasing medium having a principal emission at a wavelength shifted from the absorption wavelength. In the preferred embodiment, a CO.sub.2 laser filled with the .sup.13 C.sup.16 O.sub.2 isotope is used. The .sup.13 C.sup.16 O.sub.2 isotope generates a laser beam having a principal emission wavelength near 11.2 microns. The absorption of this wavelength in the conventional CO.sub.2 purge and insufflation gases is quite small compared to the absorption of the 10.59 micron wavelength emitted by the standard CO.sub.2 isotope. The difference in absorption allows the power generated by the laser to be maximally transmitted to the medical treatment site. In addition, the 11.2 micron line has a greater coefficient of absorption in human tissue, thereby enhancing surgery.