Low Noise and High Gain Terahertz Parametric Amplifier

In this study, we demonstrated a low-noise, high-gain terahertz (THz) parametric amplifier (TPA). The TPA is divided into two parts: a preamplifier and a main amplifier. In this configuration, wavelength conversion to near-infrared (NIR) light is performed by the preamplifier. The NIR light has different generation angles for each wavelength to satisfy the phase-matching conditions; thus, broadband noise can be spatially removed using an iris. Converting the THz wave again in the main amplifier, an improvement in amplification is realized, while reducing noise. These improvements allowed the amplification gain to reach 98 dB at 506 zJ input (zJ = 10 ^-21 J) at 0.79 THz.