DEPSCOR-95: Development of Nonlinear Optical Materials for Optical Parametric Oscillator and Frequency Conversion Applications in the Near- and Mid-Infrared

Optical nonlinearities of small polarons in lithium niobate

“…The striking role of charged point defects is reported in several prominent oxides widely applied for frequency conversion. [43][44][45] Among the materials showing polaronic effects are KNbO 3 , 46 45 Especially, the latter three materials are technologically of utmost importance for high-power laser applications. LiNbO 3 itself, particularly periodically poled LiNbO 3 (PPLN), plays an important role for low-power, tunable frequency conversion.…”

“…142 Studies of optical nonlinearities of small polarons are supported in any of these materials by means of electron-spin resonance at low temperatures. 43,44 In conclusion, the exciting interplay between optical nonlinearities commonly assigned to continuum systems on the one side and small polarons that represent localities on the other side is surveyed. The key in closing the gap between continuum and locality is either the appearance of optical excitation from small polarons to energy levels that are resonant with bandlike states as well as the observation of ensembles of small polarons with large number density.…”