• Larsen, Mads Nibe
• Jørgensen, Bjarke
• Jørgensen, Anders Løchte
• Kjelstrup-Hansen, Jakob
• Petrunin, Victor

Abstract

Fourier Transform Infrared spectroscopy (FTIR spectroscopy) is a valuable technique used to identify and characterize many kinds of materials based on their infrared reflectance/absorbance/transmittance spectra. This can be combined with a microscope and a programmable translation stage to enable hyperspectral imaging of small samples. However, this technique is ill-suited for capturing hyperspectral images of samples too large to fit under the microscope, and is usually restricted to the laboratory, as the equipment is impractical to move around.<br/><br/>This poster illustrates the working principle of a hyperspectral imaging system that combines a scanning Fabry-Pérot interferometer (SFPI) and a traditional thermal camera sensitive to wavelengths ranging from ≈ 8−15 µm.The transmission through the SFPI is determined by the distance between the interferometer mirrors, and since this distance can be controlled, the SFPI essentially functions as a variable band pass filter. It is then possible to construct a hyperspectral image cube by capturing images while sweeping the mirror separation distance. The acquired spectra are measured as a function of the mirror separation distance and not wavelength. It is possible to estimate the initial wavelength dependent spectra to make comparisons with FTIR libraries easier. <br/>Thanks to the camera’s 1024×768 pixel microbolometer sensor, the camera is capable of capturing the available spatial information at once, while scanning the spectral axis. This makes the camera ideal for performing standoff hyperspectral imaging, and the camera is portable such that it can be brought along in the field.

Topics

• impedance spectroscopy
• positron annihilation lifetime spectroscopy
• Photoacoustic spectroscopy
• Fourier transform infrared spectroscopy