We present gapless, high-resolution absorption and dispersion spectra obtained with quantum cascade laser frequency combs covering 55 cm⁻¹. Using phase-sensitive dual comb design, the comb lines are gradually swept over 10 GHz, corresponding to the free spectral range of the laser devices, by applying a current modulation. We show that with interleaving the spectral point spacing is reduced by more than four orders of magnitude over the full spectral span of the frequency comb. The potential of this technique for high-precision gas sensing is illustrated by measuring the low pressure (107 hPa) absorption and dispersion spectra of methane spanning the range of 1170 cm⁻¹ - 1225 cm⁻¹ with a resolution of 0.001 cm⁻¹.

中文翻译：

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电流调谐量子级联激光器的高分辨率和无间隙双梳光谱

我们提出了覆盖55 cm ^-1的量子级联激光频率梳获得的无间隙，高分辨率吸收光谱和色散光谱。使用相敏双梳设计，通过施加电流调制，梳线逐渐扫过10 GHz，对应于激光设备的自由光谱范围。我们表明，通过交织，频谱点间隔在频率梳的整个频谱范围内减少了四个数量级以上。这种技术用于高精度气体感测的电位通过测量低压（107百帕）吸收图示和甲烷跨越1170 cm的范围内的分散体光谱^-1 - 1225厘米^-1，0.001厘米的分辨率^-1。