| 研究実績の概要 |
While last year's work focussed on attaining high temperature operation, this year progress was made towards understanding the optical polarization properties of single photon emission from both GaN/AlGaN and InGaN/GaN quantum dots in nanowires. Indeed, single photon emission with a (raw, uncorrected) g(2)(0) measurement of 0.15 and a degree of linear polarization of larger than 95% was recorded from a site controlled GaN nanowire quantum dot at low temperature under pulsed excitation using the 3rd harmonic of a Ti:Sapphire laser (excitation of carriers directly into the quantum dot via the continuum states). At the time this result represented the most pure measurement of linealy polarized single photons from the III-nitride materials system. Work was also carried out into polar, semipolar, and nonpolar InGaN quantum dots in nanowires, where linealy polarized single photon emission was also measured for the first time. These measurements of linearly polarized single photon emission extended over a wavelength range of 480nm to 375nm (and down to 287nm when including the afforementioned GaN nanowire quantum dots) - showing that III-nitride QDs are capable of generating linearly polarized single photons over a wide range of wavelengths from the visible to the deep ultraviolet.
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