Near-field scanning optical microscope NSOM

Near-field scanning optical microscope (NSOM)... 

Nc.ar-Fi ld Scanning Optical Microscope.. The near-field scanning optical microscope (NSOM) should, strictiy speaking, be NSLM for near-field scanning light microscopy because "optical" includes electron optical as well as light optical and NSOM is a light microscope. 

Near-field scanning optical microscope (NSOM), 16 501-503 Near-infrared absorbing dyes, 9 341 Near-infrared spectroscopy (nir),... 

Science is entering into the nanoscale world, and the organization of microscale or nanoscale biomaterial structures on surfaces has been demonstrated and is a subject of extensive research effort.184,851 Single biomaterial molecules have been imaged on surfaces,186 871 and the individual affinity interactions of biomaterials probed at the molecular level.188,891 While the different scanning microscopy techniques provide useful means to image and manipulate biomaterials on surfaces, the use of the near-field scanning optical microscope (NSOM) 9<) in the activation of photoswitchable biomaterials on surfaces should be emphasized specifically. One... 

Near-field scanning optical microscopes (NSOM or SNOM) are mainly used in fluorescence and VIS measurements. They provide optical images with spatial resolution less than the Abbe s limit of Ajl. The high lateral resolution is commonly achieved by using the optical near-field, e. g. in close vicinity of a very narrow fiber tip. Figure 5.16 illustrates the design of a near-field microscope. 

Near-field scanning optical microscopes (NSOM) use a probe that emits an incredibly fine beam of... 

In this chapter, we discuss the Langmuir deposition of ultrathin PDA fihns and the subsequent measurement of their structural, optical, and mechanical properties at the nanometer scale. By altering the head group functionality, we can choose between mono- and tri-layer PDA film structures. We then show that we can use the tip of an atomic force microscope (AFM) or a near field scanning optical microscope (NSOM) tip to locally convert the PDA from the blue form to the red form via applied stress. This represents the first time that mechanochromism has been observed at the nanometer scale. Dramatic structural changes are associated with this mechanochromic transition. 

The scanning tunnelling microscope (STM) is the most suited, and the most developed of the various SPMs, to perform local spectroscopic measurements. Discussion of STM techniques will constitute the bulk of this article. It also has the most restricted range of accessible substrates in terms of conductivity and roughness. The atomic force microscope (AFM) has limited spectroscopic capabilities but can image a wider range of samples. The near-field scanning optical microscope (NSOM) has excellent spectroscopic, but limited spatial resolution. These latter two SPMs are discussed at the end of this article. 

The term SPM encompasses a family of surface-sensitive techniques, each based upon the interrogation at the nanometre level of a specific physical property by a sharp proximal probe. For example the original SPM, the STM measures local conductivity and the AFM local surface hardness. Figure 1 provides a summary of the operation of the most popular types of SPM. Extensive discussions on the operations of the various forms of SPMs can be found in numerous reviews of the subject. FFere we briefly highlight the three SPMs most readily applied to spectroscopic measurements, the STM, the AFM and the near-field scanning optical microscope (NSOM). 

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