Project: Mid-infrared frequency comb Fourier transform (FT) absorption spectrometer for time-resolved diagnostic of single events

Background information:_x000D_Fourier transform spectroscopy (FTS), also known as Fourier transform infrared spectrometry (FTIR), has assumed a position of dominance in the field of vibrational spectroscopy for more than three decades, as the versatility of this technique and the relatively low cost of the instrumentation proved much appropriate for the determination of the structure of molecules, the quantitative analysis of complex mixtures, the investigation of dynamic systems, biomedical spectroscopy, micro-spectroscopy and hyperspectral imaging, and the study of many types of interfacial phenomena. Because of the remarkable advances made in the performance of FT spectrometers, infrared spectrometry has matured to the point that it is used for the solution of a variety of problems from the research lab to the manufacturing floor, and sales of infrared spectrometers are at an all-time high. Today many companies (e.g. Bruker Optics, ABB Bomem, Thermo Nicolet, Horiba, Jasco, Perkin Elmer, Shimadzu, Varian) manufacture affordable and easy to use FT spectrometers, all based around variations of the Michelson interferometer design._x000D_However FT spectrometer design has encountered little evolution since its early breakthroughs. Current FT spectrometers are large and usually hardly transportable. The recording times are mostly limited by the speed of a moving mirror, which rarely exceeds a few centimetres per second and by the use of low-brightness incoherent light sources. For vibrational spectroscopy (i.e. 10 GHz resolution or worse), the recording times often exceeds several minutes, which is several orders of magnitude too long for the various applications linked to real-time diagnostic._x000D__x000D_Project goals:_x000D_Project COMB-SPECTRO has two objectives. _x000D_The first one is the development of mid-infrared (MIR) laser frequency comb sources. Beside their interest as the central part of the spectrometer which is targeted as the CO objective of this project, standalone turn-key MIR frequency combs hold much promise for various applications such as frequency metrology, calibration of astronomical spectrographs, ophthalmology, dermatology, femtochemistry and may even find application in Xray generation and attosecond science. _x000D_The second and CO objective of the project addresses the high versatility of frequency comb sources to develop a motionless FT MIR absorption spectrometer, with recording times of the order of a few microseconds instead of the traditional tens of seconds presently affordable in vibrational spectroscopy. The spectrometer will rely on a recently implemented concept based on the time-doCO monitoring of interferences between two frequency combs having slightly different repetition frequencies. Presently, only research proof-of-principle experiments have been demonstrated, mostly in the near-infrared region of the spectrum which is unsuitable for sensitive diagnostic. Here, the targeted spectral region is 2.5-4.5µm, where gases, liquids and solids have tell-tale absorption features associated with molecular vibrations. It is also an important window where the atmosphere is relatively transparent. The targeted development of mid-infrared spectrometers based on nonlinear mixing of the radiation of Ytterbium-doped fiber femtosecond lasers and appropriate data acquisition schemes should result in a new generation of reliable instruments, providing revolutionary vibrational spectroscopic tools for real-time broadband diagnostics. A unique feature of the analyser will indeed be its ability to measure time-resolved sequences of broadband spectra reporting the evolution of a source every 20 µs could be measured, opening new opportunities for the real-time monitoring of dynamic single-events. _x000D_The resulting compact, robust and economical analysers can be deployed in a large number of roles, such as minimally invasive medical diagnostics, environmental and workplace monitoring, industrial real-time process control and even security applications. Furthermore, the analyser could be used to assess the quality of nutrition, pharmaceutical and food products in addition to facilitating process control during production to evaluate the effectiveness of resource use._x000D__x000D_Consortium : _x000D_The consortium is formed around an industrial P, Menlo Systems GmbH and two research institutes: the Laboratoire de Photophysique Moléculaire (CNRS) and the Max-Planck Institut für Quantenoptik (MPG). The consortium brings together the world’s leading and pioneering company in optical frequency comb sources and world’s leading research institutions in the areas of frequency metrology and Fourier transform spectroscopy. The Ps represent a vertically integrated consortium, spanning from basic research to application development and production. The Ps have complementary expertise in laser source and spectrometric technique development and ruggedization and present an optimum balance of know-how to meet the challenges of the project.

Acronym COMB-SPECTRO (Reference Number: 5133)
Duration 01/01/2010 - 01/01/2013
Project Topic The COMB-SPECTRO project consortium will aim at achieving a major technological leap by developing a compact, widely applicable motionless FT-spectrometer module based the emerging technology of laser frequency comb, for time-resolved spectroscopy of rapidly-evolving chemical and biological systems.
Project Results
(after finalisation)
The project has consisted in the development and characterization of mid-infrared frequency comb laser sources based on nonlinear frequency conversion of near-infrared combs. Motionless comb-based Fourier-transform spectrometers have been conceived and implemented to interrogate fundamental vibrations of molecules in the gas and liquid phase. Such spectrometers cover a broad spectral region and measure the spectra within a very short measurement time, on the microsecond scale._x000D_Our results have been reported in scientific peer-reviewed publications and invited and contributed talks at international conferences.
Network Eurostars
Call Eurostars Cut-Off 3

Project partner

Number Name Role Country
3 Max Planck Gesellschaft zur Förderung der Wissenschaften e.V. Partner Germany
3 Menlo Systems GmbH Coordinator Germany
3 Centre National de la Recherche Scientifique Partner France