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。利用该装置，我们成功地测量了近场热辐射光谱。本研究取得的主要成果如下：1.研制了超高真空型高温STM/SNOM系统。通过改变探头与样品表面的距离，在800K时光信号发生了很大的变化。根据这一结果，证实了STM/SNOM系统探测到了近场热辐射。2.通过改变针尖调制幅度，估算了金属(W)表面的热辐射强度与距离的关系。3.用腔效应和表面等离子体极化机制解释了三种不同腔长样品的热辐射光谱。4.发现归一化区的近场热辐射强度将是远场热辐射强度的十到几百倍。

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.