Efficient Terahertz Parametric Source Using Flat Pump Beam

A flat pump beam was used to improve efficiency and miniaturize an injection-seeded terahertz-wave parametric generator (is-TPG). The improved power density of the pump beam and interaction length of the terahertz-wave reduced the required pump beam energy by > 85% compared with the conventional system. The reduced generation threshold made it possible to construct is-TPG spectroscopic systems with pump beams of ≤ 3 mJ.