초록 |
Terahertz (THz) photonics with broadband spectral region have great potential for various applications such as THz imaging and THz time domain spectroscopy. Compared to inorganic standard crystals, organic electro-optic (EO) crystals, having a large macroscopic EO response and optimal crystal characteristics, exhibit larger optical nonlinearity and excellent optical-to-THz conversion efficiency. In this work, we develop new EO crystals based on acentric core structure OHQ (2-(4-hydroxystyryl)-1-methylquinolinium) cation with electron rich naphthalene sulfonate anions for OHQ-N2S and OHQ-N1S. OHQ-N2S crystals, possessing optimal molecular packing for maximizing EO response, exhibit high THz generation efficiency at near-infrared wavelengths. We also successfully investigate crystal engineering technic to obtain large-area and suitable thickness of highly efficient EO HMQ-TMS crystal. The large area HMQ-TMS exhibits higher amplitude of generated THz wave than small area HMQ-TMS crystal. |