HiResCombs · High Resolution Molecular Spectroscopy with Quantum Cascade Laser Frequency Combs

High Resolution Molecular Spectroscopy with Quantum Cascade Laser Frequency Combs

Infrared spectroscopy provides a detailed view into the structure and bonds of molecules. It allows unambiguous identification and quantification of molecules, and can provide detailed insights into the strength of chemical bonds. Scientists can use this information to study chemical reactions in the atmosphere, the composition of the atmosphere of exoplanets, and much more. To study the energy landscape of a molecule at the level of rotational and vibrational quantum states requires instrumentation with high spectral resolution, typically based on lasers. Lasers typically only cover a very small range of the infrared spectrum, resulting in a trade off between spectral coverage and spectral resolution. Optical frequency combs are an emerging new class of lasers that have been recognized with a Nobel prize in physics. Theses laser sources emit light over a broad spectral range at exactly defined intervals, resulting in a spectrum resembling a comb. IRsweep, the beneficiary of the HiResCombs project, has developed the first commercial spectrometer based on quantum cascade laser frequency combs in the mid-infrared spectral region. The spectral resolution of the spectrometer of 0.3 cm-1 is well suited for measurements of liquid and solid samples, but insufficient for advanced studies of gases that require a high spectral resolution better than 0.001 cm-1. During the HiResCombs project, this spectral resolution will be achieved by tuning of the laser center wavelength. With this development, we want to make a turn-key spectrometer for high-resolution mid-infrared spectroscopy available to researchers of divers fields, allowing them to perform measurements over a broad spectral range with high resolution in minutes.

Data: CORDIS, © European Union