ABSTRACT
A new impetus was given to the production of the ferroelectric phase transition (KDP)-family crystals soon after the advent of lasers, when for the first time, the second harmonic of the fundamental radiation was produced at the KDP crystal using the effect of phase synchronism. At the present time, KDP-family crystals are the primary materials used in devices controlling laser radiation, its modulation, frequency conversion and scanning. They are manufactured in larger quantities than the sum total of all other crystals used in quantum electronics and all crystals grown from solutions in all their possible applications. Hundreds of papers are devoted to investigation of the physical properties of the KDP-family crystals and the number of such works does not diminish. The majority of the known data is represented in Landolt-Bornstein (1984) and in a number of reviews. The developing power optics need single-crystal elements with an aperture of 100 cm— a fantastic size for artificial single crystals.
