Infrared Hyperspectral Imaging System Based on Single-Pixel Camera(1/2)

Infrared (IR) absorption spectrum can reveal the transitions between vibrational states and is known as the molecular fingerprint. Because IR light has higher eye safety and low photodamage, IR absorption spectroscopy is suitable to be combined with daily-life applications. To overcome the limitation of pricy IR array detector, in this proposal, an IR hyperspectral imaging system (IR-HSI) based on single-pixel detector (SPD) and compressive sensing (CS) technique will be built. The wavelength range of this system is 1100-2500 nm. The wavelength information is separated by different speckle distribution after a scattering media, based on the spectral decorrelation property of the scattering media. The spatial information is coded by the linear shift-invariant property of the speckle of the scattering media. The speckle patterns corresponding to both point-source and object will be recorded and reconstructed through CS technique. Performing deconvolution algorithm on the object’s speckle pattern, an IR HSI can be reconstructed. In contrast to other systems, this system requires only modulation pattern scanning of spatial light modulator but no spectral scanning. Therefore, this system has the advantages of lower complexity, higher stability and higher imaging rate. After the system is built, it will be applied to remote detection of ethanol concentration, achieved by measuring the skin IR diffuse reflection HSI. Since ethanol has several characteristic absorption bands within 1100-2500 nm, it is possible to analyze the ethanol concentration in blood through skin IR diffuse reflection spectrum. Using the spatial information provided by HSI, it is able to study the spatial distribution variation of ethanol during the metabolism process. This research aims to develop a device to detect the ethanol concentration without collecting breath and blood samples. This device can enhance the ability to prevent drunk driving and solve the safety issues resulted from drunk driving.