High resolution heterodyne spectroscopy for studies of planetary atmospheres
We present a review of activities of the Applied Infrared Spectroscopy lab (AIRS) on high resolution heterodyne spectroscopy targeting sensitive studies of structure, composition, and dynamics of planetary atmospheres. Heterodyne method allows for unprecedented spectral resolution \(\lambda / \delta \lambda \approx 10^8\) and signal-to-noise ratio close to the quantum limit. Its implementation in ground-based astronomy by several research groups in the US, Germany, and Japan has already provided valuable information about dynamics and composition of the atmospheres of terrestrial planets. New ideas implemented at AIRS resulted in the development of a series of instruments whose scientific objectives vary from greenhouse gas monitoring to in situ sounding of the Martian atmosphere from landing platform in the near-infrared spectral range by direct Sun observation. In addition, a novel instrument for ground-bsed astronomy is being developed. The instrument employs quantum cascade lasers as heterodyne and broadband mixer based on superconducting hot electron bolometer with optical antenna. Coupling local oscillator with the signal received from a telescope is provided by a single mode fiber coupler based on fused halcogenide optical fiber. Future development will allow to implement these technologies and engineering solution onboard Earth orbiting satellites and interplanetary spacecraft.