Research on Measuring Thermal Conductivity of Quartz and Sapphire Glass Using Rear-Side Photothermal Deflection Method

Abstract

As the display industry continues to advance, various new materials are being developed for utilizing microtechnology and nanotechnology in display panels. Among these, transparent materials have been widely applied to the internal wiring of displays and flexible substrates, owing to their high optical transmittance, isotropy, and anisotropy. Thus, measurement of the thermophysical properties of various transparent materials is important. This study measured thermal conductivity by selecting quartz, a transparent isotropic material, and sapphire glass, a transparent anisotropic material, as measurement target materials using a rear-side photothermal deflection method. Measurements were made via a three-dimensional unsteady heat conduction equation, to which complex transformation was applied and numerically analyzed using COMSOL Multiphysics. Phase delays for a pump beam and a probe beam for a relative position were derived through a deflection analysis. From the derived phase delays between the numerical analysis and experimental result with optical alignment, the absolute and relative errors of quartz were appropriately confirmed to be 0.069 W/m-K and 5%, respectively, while those of the sapphire glass were likewise confirmed to be 0.55 W/m-K and 1.5%, respectively.

Efficient Heat Shielding and Ultraviolet Isolating Transparent Wood via In Situ Generation of TiO2 Nanoparticles

“…The anisotropic structure of TW leads to its anisotropy in optical properties. In order to evaluate the light guiding and directional scattering effects of TW materials, the glass, NW, and TW-3 samples were vertically irradiated by a green laser beam with a diameter of 2 mm. − The laser beam passes through the glass without scattering (Figure e), whereas the NW sample blocks the light transmittance (Figure f). In contrast, the laser beam obviously passes through the TW-3 sample.…”