Hyperspectral imaging (HSI) acquires a three-dimensional dataset called hypercube, with two spatial dimensions and one spectral dimension. HSI is an emerging imaging modality for various medical applications, especially in disease diagnosis of early and biomedical research based on their unique spectral signatures. A visible-near-infrared HSI for microspectroscopy is designed, the measured spectrum is from 450 nm to 900 nm, which is sampled by 256 spectral channels. The spatial resolution is 1.25μm.The modulation transfer function (MTF) value of full spectrum and full field of view is close to the diffraction limit. At last, this microspecroscopy have been fabricated and preliminary tests have been implemented. The results indicated this visible-near-infrared hyperspectral microscopy optical systems have excellent optical performances. This hyperspectral microscopy will be well developed and used in the life sciences fields.
Doppler asymmetric spatial heterodyne spectroscopy (DASH) with its high stability and feasibility of synchronized calibration highly suit for the wind field observation. By applying the synchronized calibration, the thermal phase distortion of observation emission line could be corrected greatly based on the similarity of thermal effects between observation emission line and calibration line. While, the correction residual which could be called relative thermal phase distortion still influence the wind measurement precision significantly. In this manuscript, we discuss and analyze the relative phase distortion of DASH theoretically and practically based on the DASH retrieval theory and the experiment. Firstly, based on the retrieve theory of DASH, we analyze the relationship between the relative phase distortion and the precision of the wind measurement. It is found that 1.528mrad phase error equal to 1m/s wind measurement error for the DASH developed by our research group. Secondly, based on the DASH developed by our research group, laser of 632.8nm and Ne lamp are employed as input source to test relationship between relative phase distortion and internal temperature of interferometer. According to the experiment result, the relative phase distortion change weekly with the variation of temperature between 25.14°C and 25.67°C. While, the relative phase stability decrease rapidly in other else temperature range. Lastly, according to the experiment result, we analyze the major source of relative phase distortion which could make contribution to reducing the relative phase error, which could increase the wind measurement precision, in the future research.