“…Nowadays, organic crystals with a large order of nonlinear coefficients are always emerging and have been attracted for various applications that include high-speed data processing, electro-optic modulation, frequency conversion, lasers, optical limiting, terahertz generation, and terahertz detection. − Usually, the organic single crystals consist of π-conjugated electron multiple donor and acceptor groups, short multiple hydrogen bonding between donor and acceptor, and strong nonlinear optical (NLO) chromophores, which leads to the large nonlinear optical coefficients and inherent ultrafast optical response as compared with the inorganic materials. For instance, organic single crystals of N , N -dimethylamino were commercialized in optical, frequency conversion as well as detection and THz generation applications due to the existence of multifunctional properties that originated through the emphatic alignment of molecular structure. − The organic molecule is more favorable to adjust the chemical structure precisely for the intended usages including optical computing, optical limiting for the sensor fabrication, optical switching, and so on .…”