Qualitative considerations are made in connection with the propagation characteristics of coherent light waves in the case where a temperature gradient exists in an optically trans-parent medium. When a temperature difference exists between the two opposite faces of plane quartz, polarization characteristics in electric field are obtained from the state of thermal stress for assumed distribution functions of temperature when it reaches a steady or a non-steady state. Upon further study in the case where a steady state temperature distribution exists between the two opposite faces of cubic quartz, similarity of phase characteristics is recognized by comparing the polarization characteristics resulting from the thermal stress calculated from the measured value of temperature distribution with the measured results of polarization characteristics from an optical experiment under the same temperature distribution. The polarization characteristics are affected by the state of temperature distribution, propagation distance and cross section area of the incident plane of laser light.
A microprocessor-controlled system of scattering radiography has been constructed. The hard and soft ware of the whole system are described in detail. To demonstrate the feasi-bility of the new radiography, we have given some structural observations of polycrystalline metal-sheets and biological materials.