Investigation of vacuum ultraviolet generation in a resonant four-wave mixing scheme in krypton with electromagnetically induced transparency

Abstract

Abstract We report experiments investigating a resonant sum-difference frequency mixing scheme in krypton producing coherent radiation at 123.6nm (i.e. in the vacuum ultraviolet (VUV)). Owing to the resonant nature of this scheme, electromagnetically induced transparency (EIT) plays a crucial role in the generation of this coherent radiation, resulting in a greatly enhanced conversion efficiency. This is the first time a resonant sum-difference mixing scheme involving EIT, that generates VUV radiation, has been investigated experimentally. Our results are in broad agreement with theoretical predictions. Measurements are presented of the dependence of VUV generation on laser detuning (in the range ± cm−1) and laser powers. In particular the dependence on the coupling field strength has been studied in the range of coupling field Rabi frequencies Ωc = 0.05−3 cm−1. We estimate an enhancement in the conversion efficiency, compared with the non-resonant case, of greater than 102.