The Research On The Terahertz Image Restoration And Detection Technology

Terahertz time-domain spectroscopy imaging technology is widely used in various detection fields,since the terahertz wave has excellent characteristics such as strong penetration to non-polar substances and high sensitivity to water.But usually,the terahertz imaging resolution is not high enough because the wavelength is from micron to millimeter magnitude,which greatly influences the effect of its application to some extent.The deconvolution image restoration algorithm is introduced in this paper,.The terahertz image is restored by using the point spread function constructed by the physical characteristics of the terahertz beam,and the image resolution is improved.Based on the construction of the point spread functions at different penetration depths in the sample,this algorithm also has the ability to obtain the chromatographic image of the sample.Subsequently,the terahertz imaging technology and the deconvolution image restoration algorithm are used to detect the internal failure of various types of electronic packaging and the water content of three leaves with different veins(wintersweet,ginkgo and bamboo)in this paper.The spatial location of the pins,the internal chip and the defect can be obtained through the restored images,besides,a variety of failure defects can be analyzed,the error of the restored image is less than 1% compared to the actual size.The terahertz image based on transmission intensity signals clearly shows the horizontal spatial distribution of the leaf water content,and reveals that the amount of water loss at the basal end is much larger than that at the distal end in the process of natural water loss.And a good agreement is reached between the terahertz imaging method and gravimetric moisture measurement.What's more,it is potential that the longitudinal distribution of leaf water content can be quantitatively analyzed through further using the deconvolution image restoration algorithm.The above results determine that the terahertz image restoration and detection technology has wide application prospects.