论文标题
通过准CW差异生成激光源在11.6-15μm范围内的高分辨率光谱法
High-Resolution Spectroscopy in the 11.6-15 μm Range by a Quasi-cw Difference-Frequency-Generation Laser Source
论文作者
论文摘要
我们报告了一种使用分子指纹区域中发出的可调激光发射的高分辨率光谱法的方法。激光基于非线性方向图案GAAS晶体中的差异频率产生（DFG）。信号激光器（一种CO2气体激光器）以KHz脉冲模式进行操作，而泵激光器（一种外部腔量子级联激光器）是无用模式的调谐。惰轮辐射的光谱范围为11.6-15μm，激光线宽为2.3 MHz。我们通过解决长波长中红外的几种混合物的吸收特征来展示开发DFG激光源的分子指纹的多功能性和潜力。此外，利用光谱仪的广泛可调节性和分辨率，我们解决了13-14.2μm的乙烯（C2H4）的宽带吸收光谱，并量化某些选定光谱线的自大系数。
We report an approach for high-resolution spectroscopy using a widely tunable laser emitting in the molecular fingerprint region. The laser is based on difference-frequency generation (DFG) in a nonlinear orientation-patterned GaAs crystal. The signal laser, a CO2 gas laser, is operated in a kHz-pulsed mode while the pump laser, an external-cavity quantum cascade laser, is finely mode-hop-free tuned. The idler radiation covers a spectral range of 11.6 - 15 μm with a laser linewidth of 2.3 MHz. We showcase the versatility and the potential for molecular fingerprinting of the developed DFG laser source by resolving the absorption features of a mixture of several species in the long-wavelength mid-infrared. Furthermore, exploiting the wide tunability and resolution of the spectrometer, we resolve the broadband absorption spectrum of ethylene (C2H4) over 13 - 14.2 μm and quantify the self-broadening coefficients of some selected spectral lines.
