抄録
High efficient frequency conversion of semiconductor lasers is necessary to obtain blue-green light for high dense optical memory, color display and so on. The principle for high effient frequency conversion and the properties of the promising inorganic materials such as KNbO3, KTP and LiNbO3 are described as well as newly developed organic materials. And the recently reported new techniques to get high conversion efficiency including external resonance cavity method, internal michrochip cavity method, quasi-phase matching method and so on are explained.
