Spectrally selective coherent thermal radiation by near-field optical effects

为了研究近场热辐射的光谱特性，研制了一套近场热辐射分析系统。利用该仪器，我们成功地测量了近场热辐射光谱。通过本研究提供的知识如下：1。本研究开发了在高温下工作的超高真空型STM/SNOM系统。通过改变探针与样品表面之间的距离，在800K时光信号发生了剧烈变化。由此证实了STM/SNOM系统探测到了近场热辐射。通过改变尖端调制的幅度，估计了金属表面热辐射强度的距离依赖关系。研究结果表明，近场热辐射集中在距离表面约6nm的范围内。用腔效应和表面等离子体-极化机制解释了三种不同腔深样品的热辐射光谱。结果表明，归一化区域的近场热辐射强度是远场热辐射强度的10 ~ 100倍。

In this study, a near-field thermal radiation analyzing system was developed in order to study the spectral properties of near-field thermal radiation. Using the apparatus we succeeded in a measurement of near-field thermal radiation spectra. The knowledge provided through this study is as follows ;1.The super-high-vacuum type STM/SNOM system operated at high temperature was developed in this study. By changing distance between the probe and sample surface the optical signal was drastically changed at 800K. From this result it was confirmed that the near-field thermal radiation was detected by the STM/SNOM system.2.The distance dependence of thermal radiation intensity from metal (W) surface was estimated by changing the amplitude of tip-modulation. From this study, it was revealed that the near-field thermal radiation was localized at about 6nm range from the surface.3.The thermal radiation spectra from three different samples with different cavity depth were explained by the cavity-effect and surface plasmon-polariton mechanism.4.It was found that the intensity of near-field thermal radiation from the normalized area will be ten to hundred times stronger than that of far-field thermal radiation.