Nonlinear terahertz-wave radiation generated by mid-infrared dual-chirped optical parametric amplification femtosecond pulse laser excitation

TL;DR

This paper presents an efficient method for generating terahertz waves using nonlinear wavelength conversion with a mid-infrared dual-chirped optical parametric amplification laser, demonstrating high energy conversion efficiencies and reduced nonlinear effects.

Contribution

It introduces a novel terahertz-wave generation technique employing a mid-infrared pump source and compares its efficiency with a near-infrared source, highlighting improved performance and reduced nonlinear effects.

Findings

Achieved a 1.3×10^-4 efficiency with the 3.3 μm source

Demonstrated pump intensities in the terawatt/cm^2 range

Reduced undesirable nonlinear optical effects using mid-infrared pumping

Abstract

We demonstrate an efficient procedure for terahertz-wave radiation generation by applying a nonlinear wavelength conversion approach using a mid-infrared pump source. We used a 3.3 {\mu}m dual-chirped optical parametric amplification source and a 1.5 {\mu}m fiber laser for a comparison of energy conversion efficiencies. Nonlinear inorganic and organic crystals were used, and for the periodically-poled lithium niobate crystal, the efficiencies were 1.3*10^-4 and 5.6*10^-12 for the 3.3 {\mu}m source and the 1.5 {\mu}m source, respectively. We confirmed that nonlinear crystals could be pumped with tera-watt / cm^2 class by using an mid-infrared source, which reduces several undesirable nonlinear optical effects.