The principle of spectrometry, which has numerous applications (medicine, astronomy, dangerous gas detection, water quality monitoring, and so on), is the accurate measurement of the wavelengths emitted or absorbed by an object, to determine its exact composition. The only problem is that spectrometers are sometimes bulky. For instance in medicine, the study of cancer cells is done with a spectrometer that fits in a shoe box. Therefore, the procedure for taking a patient's sample is sometimes painful. In astronomy, too, current spectrometers are very bulky. Thus, it is easy to see why SWIFTS (Stationary-Wave Integrated Fourier Transform Spectrometer) has a edge: it is a high resolution compact spectrometer, the smallest one ever designed. Indeed French researchers headed by Etienne le Coarer of the Astrophysics Laboratory of Grenoble (CNRS-Joseph Fourier University) engineered SWIFTS, which measures 750 x 22 x 50 micrometers.
Swifts is the outcome of a unique combination between an interferometry technique devised by Nobel Physics Laureate Gabriel Lippmann in the late Nineteenth Century and microelectronics. It involves generating wave interference in an optic according to two feasible configurations: either by setting a mirror at fiber tip (the Lippmann effect), or by separating incident light into two waves that are injected into the fiber in both propagation directions. The resulting interferogram is then measured and processed before using nanodetectors to deduce the intensity according to the wavelengths in the incident beam. As the required nanodetectors did not exist yet, they were simulated thanks to a series of gold nanowires arranged next to the fiber. The first results are encouraging. With SWIFTS miniaturization, medicine, astronomy, telecommunications, imaging and harmful gas detection should make huge strides.
