Highly efficient generation of narrowband terahertz radiation driven by a two-spectral-line laser in PPLN

We demonstrate record similar to 0.9% efficiencies for optical conversion to narrowband (<1% relative bandwidth) terahertz (THz) radiation by strongly cascaded difference frequency generation. These results are achieved using a novel, to the best of our knowledge, laser source, customized for high efficiencies, with two narrow spectral lines of variable separation and pulse duration (>= 250 ps). THz radiation generation in .5% MgO-doped periodically poled lithium niobate (PPLN) crystals of varying poling period was explored at cryogenic and room temperature operation as well as with different crystal lengths. This work addresses an increasing demand for high-field THz radiation pulses which has, up to now, been largely limited by low optical-to-THz radiation conversion efficiencies. Published by Optica Publishing Group under the terms of the Creative Commons Attribution 4.0 License.

Automated summary

In this study, a novel laser source was used to achieve efficient conversion of light to terahertz (THz) radiation, with a record efficiency of 0.9%. The generation of THz radiation in magnesium-doped periodically poled lithium niobate (PPLN) crystals was explored under different conditions. This work addresses the problem of low optical-to-THz radiation conversion efficiencies, which has limited the demand for high-field THz radiation pulses.