Characterization of carbon nano-materials by apertureless near-field scanning optical microscope-Raman spectroscopy

2012 ◽  
Author(s):  
Kyoung-Duck Park ◽  
Yong Hwan Kim ◽  
Jin Ho Park ◽  
Jung Su Park ◽  
Young-Hee Lee ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Near Field ◽  
Optical Microscope ◽  
Nano Materials ◽  
Near Field Scanning

Near-Field Optical Spectroscopy: Enhancing the Light Budget

1997 ◽  
Vol 3 (S2) ◽  
pp. 815-816
Author(s):  
M.A. Paesler ◽  
H.D. Hallen ◽  
B.I. Yakobson ◽  
C.J. Jahncke ◽  
P.O. Boykin ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Single Molecule ◽  
Raman Effect ◽  
Near Field ◽  
Optical Microscope ◽  
Diffraction Limit ◽  
Topographic Image ◽  
Optical Aperture ◽  
Near Field Scanning ◽  
Low Drift

The near-field scanning optical microscope, or NSOM, provides spectroscopists with resolution beneath the diffraction limit. In the NSOM, an optical aperture smaller than the wavelength λ of the probe radiation is scanned in the near-field of a sample. Pixels are serially gathered and then constituted as a computer-generated image. Spectroscopic NSOM investigations demonstrating sub-λ, resolution include studies of photoluminescence, Raman spectroscopy, and single molecule fluorescence. Results of nano-Raman spectroscopy on semiconducting Rb-doped KTP are shown in figure 1. Figure la is a topographic image of the sample showing a square Rb-doped region in an otherwise undoped sample. Figure lc is a NSOM region of the corner of the doped region, and figure lb is an image of the same region taken within a Raman line. While these data do provide sub-λ spectroscopic resolution and other interesting features, the weak signal provided by current NSOM technologies and the low quantum efficiency of the Raman effect necessitated development of a very low-drift microscope and inconveniently long collection times.

Near-field scanning optical microscopy

1986 ◽  
Vol 44 ◽  
pp. 642-643
Author(s):  
E. Betzig ◽  
A. Harootunian ◽  
M. Isaacson ◽  
A. Lewis
Keyword(s):  
Near Field ◽  
Optical Microscope ◽  
Visible Radiation ◽  
Field Methods ◽  
Optical Elements ◽  
Optical Region ◽  
Order Of Magnitude ◽  
Nondestructive Imaging ◽  
Scanning Optical Microscopy ◽  
Near Field Scanning

In general, conventional methods of optical imaging are limited in spatial resolution by either the wavelength of the radiation used or by the aberrations of the optical elements. This is true whether one uses a scanning probe or a fixed beam method. The reason for the wavelength limit of resolution is due to the far field methods of producing or detecting the radiation. If one resorts to restricting our probes to the near field optical region, then the possibility exists of obtaining spatial resolutions more than an order of magnitude smaller than the optical wavelength of the radiation used. In this paper, we will describe the principles underlying such "near field" imaging and present some preliminary results from a near field scanning optical microscope (NS0M) that uses visible radiation and is capable of resolutions comparable to an SEM. The advantage of such a technique is the possibility of completely nondestructive imaging in air at spatial resolutions of about 50nm.

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