Hyperspectral imaging (HI) are generally called the techniques and devices which combine in a single data set the information coming from a digital picture with the one coming from a spectrophotometer. The obtained data set, known as "hyperspectral cube", is a 3D matrix where a 2D image is combined with a third dimension giving the spectral composition of each pixel of the same image. Most popular applications of hyperspectral imaging are in chemical analysis, fluorescence microscopy, cultural heritage, thermal imaging, and spaceborne applications like Earth survey for environment or security.

At INRiM a novel technique to obtain hyperspectral imaging has been demonstrated and an imaging device has been constructed. The device is based on a scanning Fabry-Perot interferometer where the mirrors move from contact to a maximum distance by means of piezo actuators. During the cavity length scanning, a video is captured so that the light intensity variations occurring on each pixel are recorded. The interferogram obtained for each pixel is mathematically elaborated to give the spectral composition of the light hitting the same.

With respect to hyperspectral devices based on dispersive elements that have entrance and exit slits that limit the optical troughput, hyperspectral devices based on interferometers have a higher throghuput limited by the aperture of the optical system. Another advantage (also known as Fellgett or multiplex advantage) using interferometer-based spectrometers is obtained when the noise is dominated by detector noise: in this case the improvement of the signal to noise ratio is proportional to the square root of the number of bins when compared to the other spectrometers.

The responsivity of the imaging camera and the transmittance of the imaging optics limit the application of the hyperspectral imager in the electromagnetic spectrum. For example, our prototype was applied in the visible spectrum using a Si CCD in the followig fields: cultural heritage,  colorimetry,fluorescence microscopy where more fluorescent markers can be observed and discriminated on the same biological sample. It was applied in thermography and spectroscopy in the near infrared using a detector based on a InGaAs CCD. We have worked on our prototype to extend its application to the UV where we measured the UVA content of the diffused light of the sky. We are now working to extend its application to the NIR and MIR to do remote sensing of gas.