Xie Shangran, Tolstik Nikolai, Travers John C, Sorokin Evgeni, Caillaud Celine, Troles Johann, Russell Philip St J, Sorokina Irina T
Opt Express. 2016 May 30;24(11):12406-13. doi: 10.1364/OE.24.012406.
A more than 1.5 octave-spanning mid-infrared supercontinuum (1.2 to 3.6 μm) is generated by pumping a AsS-silica "double-nanospike" waveguide via a femtosecond Cr:ZnS laser at 2.35 μm. The combination of the optimized group velocity dispersion and extremely high nonlinearity provided by the AsS-silica hybrid waveguide enables a ~100 pJ level pump pulse energy threshold for octave-spanning spectral broadening at a repetition rate of 90 MHz. Numerical simulations show that the generated supercontinuum is highly coherent over the entire spanning wavelength range. The results are important for realization of a high repetition rate octave-spanning frequency comb in the mid-infrared spectral region.
通过用波长为2.35μm的飞秒Cr:ZnS激光器泵浦AsS-二氧化硅“双纳米尖峰”波导，产生了一个跨越超过1.5倍频程的中红外超连续谱（1.2至3.6μm）。AsS-二氧化硅混合波导所提供的优化群速度色散和极高非线性的组合，使得在90MHz重复频率下实现倍频程光谱展宽的泵浦脉冲能量阈值达到约100 pJ水平。数值模拟表明，所产生的超连续谱在整个跨越波长范围内具有高度相干性。这些结果对于在中红外光谱区域实现高重复频率倍频程频率梳具有重要意义。
