Dewar cooler integrated MWIR spectrometer for high rates and high dynamic range measurements

There is a need for compact, hand-held, spectrometers for the measurement of spectral signatures of chemicals or objects. To achieve this goal, a new concept of Fourier-transform interferometer (FTIR) directly integrated on the infrared focal plane array (FPA) has been developed at ONERA. The fundamental properties of this key element called MICROSPOC will be recalled and we will see how those properties can be exploited to get a snapshot, compact and cryogenic MWIR spectrometer. These design rules have been applied to develop a very compact device that combines the metrological properties of a FTIR-FPA of quantum HgCdTe technology with the radiometric performances of a last generation Sofradir detection block (Infrared Detector Dewar Cooler Assembly – IDDCA). The experimental performances of the prototype will be presented, in terms of spectral resolution, acquisition rate, dynamic range and noise equivalent spectral radiance. We will discuss at the end the potential of this technology to meet the requirements of different applications.