利用Ti宝石激光器生成的飞秒激光脉冲入射高非线性双零色散光子晶体光纤, 进行非线性光谱实验.抽运脉冲的中心波长为800 nm, 位于接近零色散点的反常色散区, 在正常色散区观测到双零色散光子晶体光纤产生的超宽带连续光谱输出, 相对于单零色散光子晶体光纤, 转换效率更高、谱带稳定而平滑, 不仅获得了高效宽带蓝移色散波, 还获得了长波段正常色散区的宽带红移色散波.实验结果与理论分析的相位匹配条件一致, 阐明了色散波产生的物理机理.随泵浦功率的增大, 长波段红移色散波发生明显红移, 可见波段蓝移色散波强度显著增长, 当泵浦功率为0.68 W时, 泵浦光几乎全部转化, 蓝移色散波与残余泵浦的输出功率之比大于257∶1, 光谱转换效率极高, 达到99.6%以上.蓝移色散波的宽带达到了309 nm, 近红外波段的红移色散波与孤子波相连, 形成超连续谱, 带宽可达628 nm.实验结果对超短脉冲激光频率转换和宽带光源的研究具有参考价值.

The nonlinear spectroscopic experiments were carried out that femtosecond laser pulses generated by Ti: sapphire laser are used to pump high nonlinear double zero dispersion photonic crystal fibers. When the central wavelength of the pump pulse is 800 nm, in the anomalous dispersion region, the ultra-wide bandwidth continuous spectral output from the double zero dispersive photonic crystal fiber is observed. Compared with that of the single zero dispersive photonic crystal fiber, double zero dispersive photonic crystal fiber has higher conversion efficiency, stable and smooth spectral band. Both the high efficiency blue shifted dispersive waves and the broadband red shifted dispersion wave in the normal dispersion region at long wavelength are obtained. Consistent with the phase matching condition of theoretical analysis, the physical mechanism of the phase matching is clarified. With the increase of pump power, the long-band dispersion wave has a significant shift to long-wave band and the short (visible) band dispersion wave intensity increases significantly. When the pump power is 0.68 W, the pump is almost completely converted. The ratio of blue shift dispersion wave to residual pump output power is 257∶1, and the efficiency of spectral conversion is as high as 99.6%. The blue shift dispersive waves has a wide band of 309 nm, and the red shift dispersive waves in near infrared band is connected with the soliton wave to form a supercontinuum spectrum with a bandwidth of 628 nm. The experiment results have reference value for the study of ultrashort pulse laser frequency conversion and broadband light source.