Improved Terahertz Generation Using BNA Derivatives

Terahertz (THz) frequencies generated from optical rectification have a wide range of applications, including hyperspectral imaging and security monitoring. Efficient THz generation largely hinges on the properties of the nonlinear THz generation crystal. We have found several high-quality crystals that enable improved THz generation, including the organic crystal BNA. One of the key properties that determines how well a material generates THz is the phase matching, which is essentially how well the speeds of the infrared pump pulse and generated THz are matched through the crystal. We demonstrate the ability to alter phase matching by making small changes to the BNA molecular structure. Of these BNA derivatives, fluoro BNA offers increased THz output and generation through improved phase matching of both the THz and near IR light pulses. Funding: NSF-DMR 2104317