The refractive indices, absorption coefficients and complex dielectric constants spectra of paraffin-embedded brain
glioma and normal brain tissues have been measured by a terahertz time domain spectroscopy (THz-TDS) system in the
range of 0.2 – 2.0 THz. The spectral differences between glioma and normal brain tissues were obtained. Our results
indicate that, compared with normal tissue, glioma had higher refractive index, absorption coefficient, and dielectric
constant. Based on these results, the suitable frequency components for different methods of glioma imaging (intensity
imaging, coherent imaging and terahertz pulsed imaging) are analyzed.
Optical rectification of laser pulses in LiNbO3 by tilted-pulse-front pumping (TPFP) is a powerful way to generate
terahertz(THz) pulses. However, comprehensive theoretical analysis is still lack. In this work, we first established and
presented a detailed theoretical model for TPFP scheme, which then was used to analyze the pump beam polarization
dependent terahertz pulses generated by this scheme. The results indicate that one can change the polarization state of the
terahertz pulse by changing the pump beam polarization. A scheme using tilted-pulse-front pumping was also set up, and
the generated terahertz pulses have maximal conversion efficiency when the pump beam electric field vector is parallel
to the crystal axis, which is consistent with theoretical model.
The refractive indices, absorption coefficients, and complex dielectric constants of paraffin-embedded brain glioma and normal brain tissues have been measured by a terahertz time-domain spectroscopy (THz-TDS) system in the 0.2- to 2.0-THz range. The spectral differences between gliomas and normal brain tissues were obtained. Compared with normal brain tissue, our results indicate that paraffin-embedded brain gliomas have a higher refractive index, absorption coefficient, and dielectric constant. Based on these results, the best THz frequencies for different methods of paraffin-embedded brain glioma imaging, such as intensity imaging, coherent imaging with continuum THz sources, and THz pulsed imaging with short-pulsed THz sources, are analyzed.