The first operating laser was developed by Maiman (1) in 1960. Since that time there has been considerable interest in the scientific and biological applications of this instrument. The laser (light amplification by stimulated emission of radiation) in brief, is an instrument which emits an intense, coherent, directional beam. Because of the fact that the beam is coherent and almost parallel, extremely small focal spots are made possible. The local energy density of irradiation which is attained is therefore extremely high. As yet, the upper limits of this power are not known. The laser may have as direct source of the emitted beam a crystal, gases, or even liquids. A semi-conductor of the gallium arsenide type as a junction diode now can produce essentially coherent light from electrical energy.
[1]
A. Clark.
Eriochrome Black T as a Protein Dye
,
1962,
Nature.
[2]
E. Franke,et al.
Pathology of the Effect of the Laser Beam on the Skin
,
1963,
Nature.
[3]
L R SOLON,et al.
Ocular Lesions Produced by an Optical Maser (Laser)
,
1961,
Science.
[4]
R. Preston,et al.
Extruded basal-cell epithelioma nodules simulating molluscum contagiosum bodies.
,
1958,
A.M.A. archives of dermatology.