Advanced Surface Probing Using a Dual-Mode NSOM–AFM Silicon-Based Photosensor

Abstract

A feasibility analysis is performed for the development and integration of a near-field scanning optical microscope (NSOM) tip–photodetector operating in the visible wavelength domain of an atomic force microscope (AFM) cantilever, involving simulation, processing, and measurement. The new tip–photodetector consists of a platinum–silicon truncated conical photodetector sharing a subwavelength aperture, and processing uses advanced nanotechnology tools on a commercial silicon cantilever. Such a combined device enables a dual-mode usage of both AFM and NSOM measurements when collecting the reflected light directly from the scanned surface, while having a more efficient light collection process. In addition to its quite simple fabrication process, it is demonstrated that the AFM tip on which the photodetector is processed remains operational (i.e., the AFM imaging capability is not altered by the process). The AFM–NSOM capability of the processed tip is presented, and preliminary results show that AFM capability is not significantly affected and there is an improvement in surface characterization in the scanning proof of concept.

Nano polarimetry: enhanced AFM-NSOM triple-mode polarimeter tip

“…As presented in previous publication 15 , there is a clear advantage in drilled photodetector, since it enables a direct reading from the surface reflection. In this approach, the first advantage is the light collection process, which will be directly performed from the surface of the sample.…”

“…One of the main advantages of this AFM-NSOM dual-mode photodetector concept, is the fact that the fabrication process is quite simple, short (few hours overall), and starts from a commercial tip. The six-step rapid process has been largely presented in the past 15 , when starting from standard commercial (FESP-V2 model from Bruker) 25 AFM silicon-based tips. Moreover, additional studies of such tip-photodetector have been presented as well 26 .…”

“…A priori, one could argue that our AFM-NSOM probe is blunt, when the contact surface is ten times larger than a commercial tip's contact diameter. In order to assure that the AFM measurement technique is still relevant, we already presented preliminary experimental results 15 for surface topography of materials scanned with these blunt AFM-NSOM probes, in order to show how the AFM imaging capability is not altered.…”

Near-field projection optical microscope (NPOM) as a new approach to nanoscale super-resolved imaging

“…The motivation to develop the NSOM technique was followed by research by Ernst Abbe 31 , which developed a criterion for resolving two separate objects. Recently, combining the two separated methods – AFM and NSOM – was also presented 32 , 33 , as well as a proposal for triple-mode 34 .…”

Funneling of Oblique Incident Light through Subwavelength Metallic Slits

“…The detailed mechanisms and many different subwavelength structures have been studied [ 14 , 15 , 16 , 17 , 18 , 19 ] because of their importance for academic research. It also has numerous applications [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ], such as in plasmonic lattices used as couplers to guide energy in an underneath subwavelength titanium dioxide layer, resulting in photonic crystal slabs [ 30 ].…”