Objective: Frequency doubling inside the resonator of a Nd:YAG laser
Materials often change their optical properties in strong electromagnetic fields. For instance, it is possible for the frequency of high-intensity laser light passing through such materials to be doubled. In this experiment, a KTP (potassium titanyl phosphate) crystal is used to generate green light with a wavelength of 532 nm from the 1064-nm infra-red radiation output by an Nd-YAG laser by means of frequency doubling. The crystal is suitable in a number of respects, such as its strongly non-linear optical characteristics, and its low absorption of radiation at the original frequency and double the frequency.