Construction Of In-situ High Pressure Optical Test System And Study On High-pressure Optical Properties Of Small Molecules

Pressure is an important physical parameter,which can directly change the state of matter.And the high-pressure environment created by diamond provides a very good optical observation window for the study of physical properties in high-pressure environment due to its broad-spectrum transmission characteristics of diamond itself.The interaction process and results of light and matter can be demonstrated by spectroscopic experiments,which can reveal the internal structure of matter and its response process.The combination of spectroscopy technology and high-pressure environment is one of the powerful tools to explore the evolution trend of physical property under high pressure and the mechanism of high pressure action.Among them,combining high-pressure technology with steady-state absorption spectrum to build an in-situ high-pressure steady-state absorption spectrum measurement system to provides the discriminating basis and pilot data of the of the optical characteristics of pressure response.Combining high-pressure technology with nonlinear optical Z-scan technology to build the experimental optical path of high-pressure Z-scan technology to realizes the study of high-pressure physical properties by non-linear optical methods.The dynamic trend of excited state with pressure evolution can be studied by combining high pressure technique with transient spectrum.In this paper,we choose perylene as the research object.Perylene as a typical aromatic hydrocarbon,because of its simple molecular structure and strong dependence on external pressure make it a candidate for studying the absorption properties and electron mobility of pressure.The high-pressure steady-state absorption spectrum of perylene shows that with the increase of pressure,the three absorption peaks of perylene gradually redshift and broaden,and cover the entire visible light region under high pressure.However,since the long molecular axis of perylene is more dependent on pressure than the short molecular axis,the absorption peak of thorium is anisotropic to the pressure response.The time of the rising part of the transient absorption spectrum of perylene at different pressures remains basically unchanged,while the fast relaxation process presents a wave-like trend,which is attributed to the pressure dependence of the perylene crystal structure.The main contents of this paper are as following:Part?,introduction.An overview of the development history of high pressure technology and the use of high pressure generator(diamond anvil cell,DAC),the development of nonlinear optics and the principle of Z-scan technology,as well as the dynamic development under high pressure.Part?,experimental techniques.Firstly,the assembling process and sample loading process of diamond anvil cell are introduced in detail.Secondly,design and construction process of the in-situ high-pressure steady-state absorption spectrum measurement system and the experimental optical path of high-pressure Z-scan technology are introduced.Finally,the measurement system of high-pressure transient absorption spectrum is introduced.Part ?,analysis of experimental data.The measured high-pressure steady-state absorption spectrum and transient absorption spectrum data of radon were analyzed.