Lasers (initial letters of the English words for Light Amplification by Stimulated Emission of Radiation - light amplification stimulated emission of radiation; synonym quantum generators) - devices for obtaining the narrow beams of light energy of high intensity.

the scheme solid state laser
The scheme solid state laser: 1 - and 4 - reflecting mirror of the cavity (4 mirror, semi - transparent) ; 2 - flash lamp pump; 3 - ruby pin; 5 - condenser; - power supply.

One of the possible concepts laser are presented in the figure. The basis of such a laser is a ruby rod surrounded by a gas-discharge lamp (the so-called lamp pumping). Radiation lamp leads to an excited state, the electrons in the atoms ruby rod. Returning to the previous state, the electrons emit energy in the form of a very narrow beam of light.
In medicine is used mainly for heat, coagulating (clotting) effects of lasers. Machines of this kind are called svetogorov. Narrow light beam of high power allows svetamaytala fabrics for fractions of a second.
Lasers are used in Oncology (therapy of superficial tumors of the skin), stomatology. They are also used in various studies in histology, Cytology (for operations on individual cells), etc., In ophthalmology laser Sotomayor is used in the treatment of some types of retinal detachment, to prevent detachment in some forms of dystrophic changes in the retina.
With the help of a laser beam cannot destroy, small tumor in the fundus, in the iris. Svetamaytala can be used for the formation of the hole in the iris or in the film secondary cataract with the purpose of reception of patients subject of view.