A new standard in high-field terahertz generation: the organic nonlinear optical crystal PNPA

We report the full characterization of a new organic nonlinear optical (NLO) crystal for intense THz generation: PNPA ((E)-4-((4-nitrobenzylidene)amino)-N-phenylaniline). We discuss crystal growth and structural characteristics. We present the wavelength dependence of THz generation, the thickness dependence of the THz spectrum for PNPA crystals, and measure the efficiency. PNPA enables intense THz generation that surpasses NLO crystals DAST and OH-1, which have been the standard in organic high-field THz generators for several years.