ABSTRACT
Potassium titanyl phosphate is one of the most common non-linear optical materials, but susceptibility to damage limits usage to low- and mid-powered lasers. The tendency of some optical materials to behave in a non-linear manner is responsible, for example, for the production of green 532nm radiation from the 1064nm YAG laser. The non-linear effect is easily understood when the nature of light in a medium is considered. Normally, atoms possess space-charge neutrality—with a strong positive charge in the center and the negative charge distributed evenly in the electron cloud surrounding it; there is no “positive” or “negative” end. Aside from the non-linear coefficient, which dictates the efficiency of a material from a “quantum” perspective, the efficiency of conversion to harmonic radiation, from an implementation perspective, depends on the inverse of the area of the beam—the smaller the area, the higher the intensity and so the larger the non-linear effect that will be observed.
