A Terahertz Wave Parametric Amplifier With a Gain of 55 dB

We report a terahertz (THz) wave amplifier based on optical parametric processes in magnesium-oxide-doped lithium niobate (MgO:LiNbO
₃
) crystals. The amplifier operates at room temperature and has a gain of 55 dB. The non-linear crystals used for the purposes of emission and amplification of the THz waves are pumped separately using a microchip laser, which leads to an enhancement of the gain in comparison with existing approaches.