Radiant energy – Photocells; circuits and apparatus – Optical or pre-photocell system
Patent
1996-05-07
1998-06-23
Le, Que
Radiant energy
Photocells; circuits and apparatus
Optical or pre-photocell system
250306, H01J 314
Patent
active
057708550
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a microscopic transmitter or detector of electromagnetic radiation which, hereinafter, is referred to as a near-field probe (1), the body of which has the form of a polyhedron point and consists of a material that is at least partially permeable to electromagnetic radiation in the spectral range used, whereby the polyhedron point is delimited by an imaginary base surface beyond which the substantial part of the body is continued to form a total body of the probe not defined in greater detail, said polyhydron point having "n " side faces in a way such that sharp edges are formed between adjacent side surfaces, such edges leading to an acute point, whereby the point of the near-field probe serves as an almost point-like source for emitting electromagnetic radiation into the external space of the probe, or as an almost point-like receiver for the penetration of electromagnetic fields into the interior of the near-field probe, whereby at least two side surfaces of the body of the polyhedron probe are coated with thin, electrically conductive layers, the latter partially absorbing the electromagnetic radiation in the spectral range used, and preferably consisting of material such as aluminum, gold or silver and having a thickness of less than 0.2 .mu.m.
2. The Prior Art
Known probes of the above type have the property that is important to their sensor function, which is that an aperture is mounted on the point in a metal film. Said known probes include: Lett. 44, 651-653), consisting of a glass or quartz fiber ending in a point, such fiber being coated with metal in such a way that an aperture is available on the point in the metal coating.
(b) The probe of Betzig et al (E. Betzig, J. K. Trautman, T. D. Harris, J. a way very similar to the one of Pohl et al, consists of glass fiber coated with metal and ending in a point, the metal coating of said fiber having a submicroscopic aperture on the point. Because of the aperture in the metal coating, the front part of the point is uncoated. Said probes have the drawback that the complex structure of an aperture in a metal film directly on the point limits the minimum dimensions of the point to about 0.1 .mu.m, whereby the aperture must not be smaller than about 15 nm. Therefore, it has to be expected that with the resolution of 13 nm achieved, the limit of the resolving capacity of the scanning near field optical microscopy SNOM (Scanning Near Field Optical Microscopy) has been reached with such points. At the same time, the width of the point of at least 0.1 .mu.m conditions that the aperture can be brought close to the surface to a distance of less than 15 nm only in exceptional cases, such distance being required for obtaining the resolution of 15 nm.
The tetrahedron probe described by Danzebrink and Fischer, which is specified in application DE 43 29 985 A1, has the same drawback. However, versus the probes described above in (a) and (b), said probe has the advantage that it satisfies the function of the transmission element in a superior way.
Since the aperture satisfies the function of the SNOM-probe in both cases, said probe not being electrically conductive everywhere, a simultaneous SNOM and scanning tunnelling microscopy with high lateral resolution is not possible with the identical point in said cases.
SUMMARY OF THE INVENTION
The invention is based on the problem of creating an efficient near-field probe with which a resolution as high as possible can be achieved in scanning near-field optical microscopy, and which permits simultaneous scanning tunnelling microscopy with the same point.
The solution of said problem is obtained according to the invention in that also the most frontal part of the polyhedron point is coated with the coating material used. Said device has the advantage that the resolution of a near-field microscope equipped with said probe is no longer limited by the aperture because the most frontal part of the point itself serves as the emitter or re
REFERENCES:
patent: 4604520 (1986-08-01), Pohl
patent: 5270543 (1993-12-01), Visser et al.
patent: 5289004 (1994-02-01), Okada et al.
patent: 5389779 (1995-02-01), Betzig et al.
Science, vol. 251, pp. 1468-1470 -- E. Betzig, J.K. Trautman, T.D. Harris, ", Jan. 1991. "Optical stethoscopy: Image recording with . . . ".
LandOfFree
Microscopic electromagnetic radiation transmitter or detector does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Microscopic electromagnetic radiation transmitter or detector, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Microscopic electromagnetic radiation transmitter or detector will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1396412