Research On Optical Parameters Of Wood Tissue Based On Double-Integrating-Sphere System

In this paper,the transmission mechanism and analysis method in biomedical study has been conducted into the field of wood analysis.The study include two aspects mainly:on one hand,the near-infrared transmission spectra of different species of wood have been collected to clarify the best transmission wavelength.On the other hand,a double-integrating-sphere system has been established to measuring optical parameters of different species of wood.Then the absorption coefficient and scattering coefficient have been calculated by using Inverse Adding Doubling program.Following main conclusions are obtained:1.The study has selected the typical species of plantation timber to collect the NITS of different thickness samples for analysis.The processed spectra data shows that the best wavelength of near-infrared transmission in wood tissue is 1310nm.2.The paper has introduced the technology of measuring optical parameters of turbid media and detailed the advantages and the measuring principle of the double-integrating-sphere system and described the design ideas of the system generally.A double-integrating sphere system based on lock-in amplifier has been set up.Experiments show that the double-integrating sphere system performing a reasonable signal to noise ratio,can be applied to data collection.3.Absorption coefficient correlates closely with the type and content of chemistry material in wood;scattering coefficient correlates closely with the size of scattering particles in wood.The experimental datum has demonstrated:The absorption coefficient of Cunninghamia lanceolate is 0.053 equally while the scattering coefficient on average is 4.75;The absorption coefficient of Populus is 0.055 equally while the scattering coefficient on average is 5.94;The absorption coefficient of Paulownia is 0.053 equally while the scattering coefficient on average is 5.41.