Bing Xue

Characteristic research of photoconductive antenna for broadband THz generation

Photoconductive effect based on femtosecond laser pulses to generate terahertz (THz) pulses has been analyzed, and broadband THz radiation has been detected effectively by using the free space electro-optic sampling (FE-EOS). Furthermore, THz pulses generated by the home-made photoconductive antenna and transmitted through the air have been detected by the THz time domain spectroscopy (THz-TDS) system, and the influences under different conditions employed on photoconductive antenna for THz generation have been measured and discussed.

Simulation analysis of the antenna structure for terahertz generation

The research on terahertz (THz) fields exists for decades of years, because of its promising applications in imaging, medical diagnosis, security inspection, information communication, etc. There are many ways to generate THz pulses, such as photoconductive effect, optical rectification, photomixing, and so on. For the detection of THz pulses, two methods, free space electro-optic sampling (FS-EOS) and photoconductive (PC) sampling, can be normally used. In our previous experiments, the photoconductive effect has been utilized to generate THz radiation from a piece of semiconductor with antenna structure. The amplitude of THz signals was found to be proportional to the magnitude of the electric field. To understand this more clearly and try to get better THz signals, simulation analysis of the electric field in between the electrodes of the photoconductive antenna has been done, and a optimized antenna structure which will be more efficient than the parallel dipolar electrodes has been designed based on the simulation analysis.

Image enhancement techniques used for THz imaging

Terahertz (THz) radiation has been widely applied in the areas of spectroscopy, sensing and imaging. With the advancement of THz technologies, THz imaging has been progressed significantly and has huge potential applications in medical diagnosis, environmental control, chemical and biological identification. In the past, people mainly focused on overcoming the obstacles in the hardware, such as the limitation of resolution, accuracy and speed in THz imaging system. In this paper, image enhancement techniques are employed to enhance the contrast and get the better profile of THz image. Our results clearly demonstrate that digital image processing techniques can suppress noise effectively, extract target edges robustly, and therefore improve the quality of THz image.181