Improved signal-to-noise ratio in a passive THz near-field microscope equipped with a helium-free cryostat
Improved signal-to-noise ratio in a passive THz near-field microscope equipped with a helium-free cryostat
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DOI：
10.1109/irmmw-thz.2016.7758551
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发表时间：
2016-09
期刊：
影响因子：
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通讯作者：
K.-T. Lin;S. Komiyama;S. Kim;K. Kawamura;Y. Kajihara
中科院分区：
文献类型：
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作者：
K.-T. Lin;S. Komiyama;S. Kim;K. Kawamura;Y. Kajihara
我们已经开发了一个被动太赫兹s-SNOM（散射型扫描近场光学显微镜）配备了无氦低温恒温器。压缩机的机械振动被减少，以精确控制探针-样品距离。此外，采用固体浸没透镜的共焦系统可以获得更高的信噪比。为了证明的s-SNOM的能力，我们测量了热激发表面倏逝波的Au/SiO2样品。在0.1 s/像素的扫描速率下，在Au上实现的近场信号的SNR为5.5。结果表明，改进的被动s-SNOM不仅提供了更方便的冷却过程，而且显着加快了被动太赫兹近场图像的扫描速率。
We have developed a passive THz s-SNOM (scattering-type scanning near-field optical microscope) equipped with a helium-free cryostat. The mechanical vibration from the compressor is reduced for accurately controlling the probe-sample distance. Besides, the confocal system with a solid immersion lens leads to gather higher signal-to-noise ratio. To demonstrate the capability of the s-SNOM, we measured the thermally excited surface evanescent wave on a Au/SiO2 sample. Achieved SNR of the near-field signal on Au is 5.5 with a 0.1 s/pixel scan rate. These results show that the improved passive s-SNOM not only provides more convenient cooling process but also significantly speeds up the scan rate for the passive THz near-field image.