Development of the external cavity for IR heterodyne spectroscopy

我们开发的外腔系统在中红外波长作为本机振荡器的外差接收机的火星大气甲烷和相关物种的观测。使用Littrow光栅设置证明了超过20 cm-1的调谐，并且其允许甲烷和过氧化氢的分子跃迁的良好覆盖。我们表明，它的光谱稳定性和边模抑制是优秀的红外外差测量。

We develop the external-cavity system at mid-infrared wavelengths as a local oscillator in a heterodyne receiver for observations of Martian atmospheric methane and related species. Tuneability over 20cm-1 was demonstrated using a Littrow-grating setup, and which allows for good coverage of molecular transitions of methane and hydrogen peroxide. We show that its spectral stability and side mode suppression are excellent for IR heterodyne measurements.