Double Electro-optic Molecular Polymer And Its Application In THz Wave Detection

Terahertz(THz) wave is a new research direction in the electromagneticspectrum. Because of the series of special performance, it has broad applicationprospects in dielectric materials, biological medicine, physical, chemical, security,communications, and so on. Some characteristics, such as dielectric properties,conductivity, and space charge properties, etc, usually need to be got in ourresearch on insulating properties of dielectric materials. Using THz technology toget various performance indicators of dielectrics at this frequency has a veryimportant significance in further research of dielectric insulation performance. Inthis thesis, the mainly work is to set up a stable system of THz wave generationand detection, and prepare a kind of double electro-optic molecular polymer,which is used in THz wave detection process.In this paper, All-Optical technology is used to achieve THz wavegeneration and detection, namely the optical rectification method to generateTHz wave, and electro-optic sampling technology to detect THz wave by usingtraditional electro-optic crystal. The optical rectification method and electro-optic sampling technology is briefly analyzed, the experimental platform systemis set up, and the experimental testing method is summarized. The THz waveformin time domain and frequency domain is finally gained with fast Fouriertransform.Due to advantages of the electro-optical polymer, such as high electro-opticcoefficient, fast electro-optic response, well film forming property, widefrequency response width, easy chemical synthesis and improvement, more andmore electro-optical polymers are applied in THz technology research in recentyears. This thesis use double electro-optic molecular polymer, which is mixed with small electro-optical molecule, to improve the performance of intrinsicelectro-optic polymer, and measure its electro-optic coefficient. In this paper, atheoretical derivation of the simple reflection method is done, the experimenttesting system is set up, and the electro-optic polymer film is prepared. Theinfluence on electro-optical coefficient, glass transition temperature and othercharacteristics of electro-optic polymer doped with different proportions ofelectro-optical molecule is studied.High electro-optic coefficient, appropriate doping ratio and polingtemperature are chosen to prepare THz wave detector. THz wave is generated byelectro-optic crystal in the experiment, and the time domain and frequencydomain waveform of THz wave is detected by THz wave detector, which is madeup by double electro-optic molecular polymer.