Nakamura Toshihiro, Hosaka Tomohiro, Adachi Sadao
Graduate School of Engineering, Gunma University, Gunma, Japan.
Opt Express. 2011 Jan 17;19(2):467-75. doi: 10.1364/OE.19.000467.
We demonstrate Au-nanoparticle-assisted random lasing from a powdered GaN sample. In the presence of Au nanoparticles on GaN powder surfaces, several lasing lines are observed in photoexcited luminescence spectra near the center of the GaN band-edge emission peak. The random lasing is considered to arise from a decrease in the lasing threshold due to the suppression of crystal defect loss by surface plasmon excitation on Au. From spatially resolved lasing emission spectra and their FT analysis results, the formation of random lasing cavities at different spatial positions is confirmed. The size of the random lasing spot is determined to be larger than that of the scattered light speckle of the pumping source on a thin powdered GaN sample.
我们展示了在粉末状GaN样品中由金纳米颗粒辅助的随机激光发射。在GaN粉末表面存在金纳米颗粒的情况下，在GaN带边发射峰中心附近的光激发发光光谱中观察到了几条激光线。这种随机激光发射被认为是由于金表面等离子体激元激发抑制了晶体缺陷损耗，从而降低了激光阈值所致。从空间分辨的激光发射光谱及其傅里叶变换分析结果可以确认，在不同空间位置形成了随机激光腔。确定随机激光光斑的尺寸大于薄粉末状GaN样品上泵浦源散射光散斑的尺寸。
