Nonlinear optical materials are generally applied in high-tech fields such as laser, communication, medical equipment, electronic facility. Studying on chiral organic materials which structure can be changed by purpose is becoming a focus in optical material fields. Now this study is still in the starting phase. Among these studies the Urea, an organic crystal, had been successfully applied in second harmonic generation of ultra-violet. However, because of the easily deliquescence crystal, strict growth con...