Study of THz Generation from DAP:NP Crystals by Femtosecond Laser Pulses
Luo, Chih Wei
|關鍵字:||兆赫波;有機非線性光學材料;THz;organic nonlinear optical materials|
DAP:NP(2,6-diaminopyridine-4-nitrophenolate-4-nitrophenol) crystals are the new organic nonlinear optical materials. In this study, we have firstly generated the THz radiation from DAP:NP crystals by using femtosecond laser pulses. The amplitude of THz radiation is strongly dependent on the azimuthal angle of DAP:NP crystals and show the six-fold symmetry with the configuration of P-polarized pump and P-polarized probe (Ppump-Pprobe), two-fold symmetry with the configuration of S-polarized pump and P-polarized probe (Spump-Pprobe). These results indicate that the THz generation mechanism is optical rectification, which is also consistent with the theoretical calculations. Moreover, the crystal structure and optical properties of DAP:NP crystals were also studied by the x-ray diffractometer, UV-VI-NIR spectrometer, and second harmonic generation system.