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