Large-aperture, manually-poled LiNbO3 and KTP for efficient, narrowband THz generation

Large-aperture, manually-poled LiNbO
3
wafers have already been used to generate THz radiation. However, the results were limited to room-temperature operation with only a few cycles. Here, we extend the number of cycles and improve the efficiency by increasing the number of wafers and using another non-linear material, KTP, at cryogenic nitrogen temperature.