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Chen Y.,Soochow University of China | Chen Y.,Key Laboratory of Advanced Optical Manufacturing Technologies of Jiangsu Province | Chen Y.,Key Laboratory of Modern Optical Technologies of Jiangsu Province | Chen Y.,Key Laboratory of Modern Optical Technologies of Education Ministry of China | And 16 more authors.
Guangxue Xuebao/Acta Optica Sinica | Year: 2014

Optical compressive spectral imaging method is a novel spectral imaging technique that draws in the inspiration of compressed sensing, which has the features such as reducing acquisition data amount, realizing snapshot imaging for certain scenery, increasing signal to noise ratio and so on. Considering the influence of the sampling quality on the ultimate imaging quality, matching the sampling interval with the modulation interval in the former reported imaging system, while the depressed sampling rate leads to the loss on the original spectral resolution. To overcome that technical defect, the demand for the matching between sampling interval and modulation interval is disposed and the spectral resolution of the designed experimental device increases more than threefold comparing with that of the previous method. Optimization method is improved and a variation term that represents the spectral-dimension continuousness of the data is added to the regularization function, which enhances the controllability and reliability for the data reconstruction. Result proves that the spectral channel number increases to a great extent effectively, the average spectral resolution reaches 1 nm, and the spectral images and curves are able to perform the spatial and spectral character of the target accurately.


Chen X.,Soochow University of China | Chen X.,Key Laboratory of Advanced Optical Manufacturing Technologies of Jiangsu Province | Chen X.,Key Laboratory of Modern Optical Technologies of Education Ministry of China | Shen W.,Soochow University of China | And 2 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

In this paper, we propose an aberration retrieval method for annular pupils using proposed parametric model of point spread function (PSF). With this model, the diffraction integral for annular pupils is expressed with Bessel-series representation and annular Zernike coefficients. Conjugate gradient algorithm is used to retrieve aberration coefficients of annular pupil from the corresponding spot intensity images. The iterative calculations of objective function and its gradient function are required for this algorithm. These calculations are accelerated by using the parametric model's analytical expression instead of Fourier transforms. Numerical simulation and experiment are performed to validate this aberration retrieval method. © 2012 SPIE.


Chen X.,Soochow University of China | Chen X.,Key Laboratory of Advanced Optical Manufacturing Technologies of Jiangsu Province | Chen X.,Key Laboratory of Modern Optical Technologies of Education Ministry of China | Shen W.,Soochow University of China | And 2 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014

Phase retrieval method can determine pupil phase directly from image formed by the optical system with no extra hardware. This method has attracted more and more attentions for its unique advantage, and has been successfully applied in many domains such as large telescope alignment, X-ray imaging and so on. In this paper, we propose a hybrid phase retrieval method for annular pupil, which is composed of two steps. In the first step, the estimated spot images is computed with analytic expression, while fast Fourier transform is used in the second step. This method can achieve high retrieval speed without sacrificing the retrieval accuracy. Numerical simulation is performed to validate this phase retrieval method. © 2014 SPIE.


Zhou J.,Soochow University of China | Zhou J.,Key Laboratory of Advanced Optical Manufacturing Technologies of Jiangsu Province | Zhou J.,Key Laboratory of Modern Optical Technologies of Education Ministry of China | Chen X.,Soochow University of China | And 11 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014

The radiometric calibration of imaging spectrometer plays an import role for scientific application of spectral data. The radiometric calibration accuracy is influenced by many factors, such as the stability and uniformity of light source, the transfer precision of radiation standard and so on. But the deviation from the linear response mode and the polarization effect of the imaging spectrometer are always neglected. In this paper, the linear radiometric calibration model is constructed and the radiometric linear response capacity is test by adjusting electric gain, exposure time and radiance level. The linear polarizer and the sine function fitting algorithm are utilized to measure polarization effect. The integrating sphere calibration system is constructed in our Lab and its spectral radiance is calibrated by a well-characterized and extremely stable NIST traceable transfer spectroradiometer. Our manufactured convex grating imaging spectrometer is relative and absolute calibrated based on the integrating sphere calibration system. The relative radiometric calibration data is used to remove or reduce the radiometric response non-uniformity every pixel of imaging spectrometer while the absolute radiometric calibration is used to construct the relationship between the physical radiant of the scene and the digital number of the image. The calibration coefficients are acquired at ten radiance levels. The diffraction noise in the images can be corrected by the calibration coefficients and the uniform radiance image can be got. The calibration result shows that our manufactured imaging spectrometer with convex grating has 3.0% degree of polarization and the uncertainties of the relative and absolute radiometric calibrations are 2.4% and 5.6% respectively. © 2014 SPIE.

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