Microscopic absorption measurement with enhanced sensitivity by using focused surface plasmons

作者：Ning, Jun; Sato, Hiroki; Hereid, Aomintanggesi; Kano, Hiroshi^*

来源：Optics Communications, 2018, 427: 405-408.

DOI：10.1016/j.optcom.2018.06.063

• Surface plasmon
• Absorption
• Optical constants
• Optical instruments

We propose a technique to enhance absorbance of a sample with ultra small volume by using surface plasmons excited in a microscopic region on a flat metal surface. In this technique, the absorbance is measured from the variation of reflected intensity at around the propagating constant of excited surface plasmons in a spatial frequency spectrum. We demonstrate that a wider and deeper dip appears in the spatial frequency spectrum by placing an absorbing droplet sample instead of a non-absorbing sample. An experimental result employing methylene-blue water solution as a sample reveals absorbance enhancement by a factor of 19 from a measurement by attenuated total reflection method.

• 出版日期2018-11-15
• 单位内蒙古师范大学