Terahertz parametric detection using a lithium tantalate

Opt Lett. 2025 Jan 15;50(2):527-529. doi: 10.1364/OL.544632.

Abstract

Terahertz (THz) parametric detection is a highly sensitive method that upconverts a THz wave into a near-infrared beam for detection. Lithium niobate has primarily been used as the nonlinear optical crystal in this approach. However, the frequency band with high parametric gain is limited, leading to increasing interest in other nonlinear optical crystals. Here, we demonstrate that lithium tantalate provides high-sensitivity detection at low frequencies, achieving a maximum improvement of 15 dB over the 0.8-1.5 THz band.