Development of DAST-derivative crystals for terahertz waves generation

Bis[4-dimethylamino-N-methyl-4-stilbazolium] terephthanate (BDAS-TP) was newly designed as an organic nonlinear optical crystal. It is derivative of 4-dimethylamino-N-methyl-4-stilbazolium tosylate (DAST), which is well known as a novel terahertz (THz)-wave emitter. We also succeeded in growing single crystals of BDAS-TP for the first time by using a solution-slow-cooling technique. By using a femtosecond laser, we obtained a broadband THz spectrum from BDAS-TP crystal.