Theory Of Continuously Modulating PTR And Application In Characteristic Measurement Of The Thermally Uniaxial Material

In the first part of this thesis, history of PTR technology and measuring equipment were introduced. We have summarized the continuously modulating PTR theory of isotropic materials, and formed a complete system info concluding one dimension and three dimensions theories, monolayer and multilayer theories. Some applications of PTR technology were simply introduced in this part.In the second part, we have mainly introduced a method for measuring the principal conductivity and axial orientation of thermally uniaxial material by PTR technology. Based on the PTR theory of anisotropic material studied by some people, we have analyzed photothermal signal from rear side of the sample, gained expressions of amplitude and phase. We would use these expressions to fit experiment data to get a conductivity value. We have made a model of thermally uniaxial material to find the expression between the conductivity and principal conductivity. We have gained four expressions of conductivity in four special directions by transforming coordinates. In application when we get the fitting result, we can calculate the principal conductivityvalue and axial orientation with those expressions.