Principles of Endoscopic Laser Surgery
Electrons orbit in the atom at different distances from the nucleus. When an atom is “excited” by an external energy (in the form of a photon), electrons are shifted to an orbit further from the nucleus. The more energy absorbed by the atom, the higher the resulting orbit level of its electrons. This excited state lasts approximately a few millionths of a second until the electron drops down (decays) to its usual level to maintain thermodynamic equilibrium. During this decay the energy absorbed by the electron is emitted in the form of a photon, a process termed spontaneous emission. If an atom is in the excited state and is struck with another photon of the same energy as the one already absorbed, the decay process is accelerated. When this happens, two photons of identical energy, frequency, and direction are released, in a process termed stimulated emission. This principle is the basis for the production of LASER (Light Amplification Stimulated Emission of Radiation) light. The energy released by an atom during spontaneous or stimulated emission represents the difference between the initial and final energy of that atom, which in turn depends on the particular species of atom and its various electron orbits. Thus, different materials will produce lasers of different wavelenghts or energy (Fig. 6.1).
KeywordsTitanium Quartz Dioxide Welding Argon
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- 5.Daniell JF, Meisels S, Miller W, et al. Laparoscopic use of the KTP/532 laser in nonendometriotic pelvic surgery.Colposcopy Gynecol Laser Surg. 1986;2:107–111.Google Scholar
- 9.Sutton CJ, Ewen SP, Whitelaw N, Haines P. Prospective, randomized, double-blind, controlled trial of laser laparoscopy in the treatment of pelvic pain associated with minimal, mild, and moderate endometriosis.Fertil Steril. 1994;62: 696 –700.Google Scholar