Efficient broadband terahertz generation from organic crystal BNA using near infrared pump

Abstract

We report on terahertz (THz) generation from organic crystal N-benzyl-2-methyl-4-nitroaniline using a 1.15–1.55 μm near infrared pump. We observed a very large emission spectrum extending up to 7 THz, compared to 2.5 THz from a Ti:Sa pump in previous reports. The maximum optical-to-THz conversion efficiency in our experiment was 0.8% at a repetition rate of 1 kHz and without saturation, leading to a peak electric field of 1 GV/m. Our results show pronounced phase matching privilege for intense terahertz generation using a pump in the 1.15–1.25 μm range where high energy near infrared pump sources operate.