Low-Power, Long-Wavelength Infrared Lasers for Planetary Science Spectrometers
Following the success of the tunable laser spectrometer aboard the Mars Curiosity rover, laser-based spectroscopy instruments are expected to play a vital role in future planetary science missions. By selectively targeting absorption lines of key atmospheric gases and their less abundant isotopologues, next-generation instruments can provide valuable information on the composition and origins of bodies throughout the solar system. Lasers emitting in the long-wavelength infrared regime can probe strong absorption lines of many compounds relevant to planetary science. However, at wavelengths beyond 6 µm, commercial lasers are not presently available with the low power consumption required for in situ instrument payloads. MDL is building single-mode quantum cascade (QC) lasers with emission wavelengths in the 7 to 10 µm range and power consumption below 1 W. These devices will enable the development of tunable laser spectrometers designed for important measurements, including studies of the abundance and isotopic composition of sulfur dioxide in the atmosphere of Venus as well as ammonia and phosphine in the atmospheres of the outer planets.