THz spectral imager based on three-dimensional phase grating and aperture segmentation technology

Abstract

The invention discloses a THz spectral imager based on a three-dimensional phase grating and aperture segmentation technology. The THz spectral imager is constituted by a front lens, a front visual field diaphragm, a front collimating mirror, a three-dimensional phase diaphragm, a rear converging mirror, a rear visual field diaphragm, a rear collimating mirror, a sub-aperture imaging mirror, a detector, a detector control processing system, and a control acquisition processing computer. The detector is used to acquire light intensity information of N zero-order diffraction light diffracted by N cells of a three-dimensional phase grating in a target scene by a adopting an aperture segmentation way, and according to N optical path differences corresponding to the N cells of the three-dimensional phase grating, data of corresponding relation between N optical path differences and light intensities is acquired. By adopting Fourier transform, the THz spectrums and the THz images of the target are acquired in a real-time manner, and the THz spectral imager is suitable for the THz spectrum detection, analysis, and other related fields.

Description

technical field [0001] The invention relates to a terahertz spectrum imager, in particular to a spectrum imager capable of acquiring target THz spectrum and image information in real time. The THz spectral imager consists of a front mirror, a front field of view diaphragm, a front collimator, a stereoscopic phase grating, a rear converging mirror, a rear field of view diaphragm, a rear collimation mirror, and a sub-aperture imaging mirror. , detector, detector control processing system and control acquisition processing computer. The detector simultaneously acquires the light intensity information of N zero-order diffracted lights of the target scene diffracted by the N cells of the stereoscopic phase grating in an aperture division manner, according to the N optical paths corresponding to the N cells of the stereoscopic phase grating Obtain the corresponding relationship data between N groups of optical path difference and light intensity, and obtain the THz spectrum and ima...

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Problems solved by technology

[0005] The shortcomings of the above two kinds of prior art are mainly reflected in the following aspects: one, Fourier spectrometer and THz-TDS, it takes a long time to complete the imaging process of the object, which is not suitable for complex and changeable environmental conditions, and the target is too large. The real-time detection and imaging requirements of the Hertz spectrum; 2. THz-TDS is used to measure the transmittance and reflectance characteristics of materials in the THz band in the laboratory environment, and is not suitable for the THz spectrum detection and detection of limited-distance targets in the field environment. Imaging applications; 3. Fourier spectrometer and THz-TDS, which are bulky and not easy to carry

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