An accurate method of estimating polarized light emission was presented for nonpolar m-plane InGaN-based blue light emitting diodes, where the unpolarized component caused by unintentional light scattering was eliminated as noise. The polarization ratios of electroluminescence (EL) at 300 and 100K were 0.85 and 0.98, respectively. The energy difference between the highest and the second highest valence bands was estimated to be 129meV from the temperature dependence of the spectrally integrated EL intensities under the assumption of Fermi statistics. This value agreed with the one (=118meV) obtained directly from the difference of the EL peak energies between two polarized components, the electric fields perpendicular and parallel to the c axis.

Polarized electroluminescence (EL) from m-plane InGaN-based blue light emitting diodes (LEDs) has been investigated. These LEDs comprised a ZnO transparent electrode as an anode, polished mirror-like sidewalls, and a polished backside with the reflective mirror to remove the light scattering due to the surface roughness. The polarization ratio at room temperature was 0.80, which was relatively high compared to known values and was considered to be close to the true value. The reduction of the light scattering is essential for the accurate measurement of the polarized emission. The EL spectra from different three planes, i.e., m-, c-, and a-planes, have been measured. The peak energies of spectra polarized parallel to m-plane, emitted from a-and c-plane sidewalls, agree with the values of the two components emitted from top m-plane surface. The strongest component was E ? c while the second strongest was E k c. The E k m component was extremely low compared with E k c.

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A model that introduces surface tension as a pressure boundary condition, named the surface tension as pressure (STP) model, was developed for free surface flow analyses by the moving particle simulation (MPS) method. The STP model assigns to surface particles the liquid pressure of Laplace’s formula. The model is an alternative to previous models that apply surface tension as volume force such as the continuum surface force model. Problems that appeared when using the volume force models, such as the dependencies of calculation results on particle resolution and pressure gradient accuracy, were solved by using the STP model. Calculations predicted the theoretical values of the internal pressure of a 3D spherical droplet and the oscillation period of a 2D elliptic droplet over a wide range of surface tension coefficients and droplet sizes with errors less than 10%. Since the STP model is easy to implement, does not increase computation cost from previous models, and does not require surface reconstruction or additional marker particles, the model is suitable for practical and large-scale free surface flow problems that involve violent deformation of the liquid surface such as liquid atomization.

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