Monday, May 16, 2016
Abstract-Improvement of Measurement Resolution of Depth Distribution in Cross-Sectional Imaging Using Terahertz Wave
Time-resolved reflection measurement using broadband, short terahertz pulses can provide cross-sectional images of dielectric materials at different depths. Low-frequency components which have responses over a wide time range may result in inclusion of spurious signals which arise from strong reflections at other depths. Model calculations showed that such spurious signals can be suppressed by application of a frequency filter of an appropriate center frequency. The effect of frequency filtering was investigated in cross-sectional imaging of an IC card. Cross-sectional images were obtained at depth intervals of 0.18 mm, which provided images at five different depth intervals. As a result of frequency filtering, spurious signals resulting from strong reflections at different depths could be reduced in intensity, which resulted in improvement of the measurement resolution of the depth distribution.