Boosting efficiency and accurate modeling of parametric down-conversion processes

摘要

Conversion efficiency is boosted by using tandem crystal optical parametric amplifier geometry. We have undertaken comprehensive numerical modeling of the optical systems, where the output beam for the first stage are calculated and then propagated to the second stage. As a concrete example periodically poled lithium niobate crystals are experimentally examined. The phase and amplitude information about the pump and signal beams were retrieved using the Fresnel phase retrieval method and used as input in the theory. This enabled real laboratory conditions to be modeled. Subsequently, the amplitude and phase of the complex pump and signal beam from the crystal was calculated and the results were validated by experiments. Non-collinear interactions in the second stage also yielded an efficient idler output over a broad range of temperatures. ZnGeP_2 crystals were used in the numerical simulations with first and second stage amplification. We predicted an idler energy increase by a more than a factor of 3.