磷化镓高功率太赫兹共线差频源的研究

Investigation of high power terahertz emission in gap crystal based on collinear difference frequency generation

在众多实现太赫兹辐射的方法中,非线性光学共线差频能够实现高功率、宽波段、连续可调谐的太赫兹波辐射.理论分析表明,各向同性磷化镓晶体,在1064nm附近波长激光共线差频下具有毫米量级的相干长度,能够满足高功率宽波段的太赫兹辐射条件.实验证明,磷化镓晶体共线差频实现高功率宽波段的太赫兹光辐射,其太赫兹光波长调谐范围为95.9—773.4μm(0.39—3.13THz),最高峰值功率7W位于频率2.0THz处.该实验结果与理论计算基本保持一致.

Among many terahertz wave generation methods, nonlinear optical collinear difference frequency generation （CDFG） is always regarded as a promising way to achieve the high power, broadband, continual tunable terahertz wave emission. Theoretical analysis shows that a big coherent length （on millimeter scale） in isotropic GaP crystal could be realized by the laser wavelength near 1064 nm in the CDFG process, which meets the condition of high power and broadband terahertz generation. In the experiment, a high power and broadband terahertz wave is achieved from GaP crystal, with its tunable terahertz range 95.9-773.4 μm （0.39-3.13 THz） and the highest terahertz peak power 7 W at 2 THz. The experimental result is generally consistent well with its theoretical calculation.