Near-field microscope

• US 20020056807A1
• Filed: 11/07/2001
• Published: 05/16/2002
• Est. Priority Date: 11/13/2000
• Status: Active Grant

• Current Assignee: Jasco Corporation
• Original Assignee: Jasco Corporation
• Inventors: Narita, Yoshihito, Kimura, Shigeyuki
• Granted Patent: US 6,710,331 B2
• Time in Patent Office: Days
• US Class Current: 250/234
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 35/00 Methods or apparatus for measurement or analysis of nanostructures
• CPC Class Codes: G01Q 10/06 Circuits or algorithms therefor
• CPC Class Codes: G01Q 30/06 for error compensation
• CPC Class Codes: G01Q 60/22 Probes, their manufacture, or their related instrumentation, e.g. holders
• CPC Class Codes: Y10S 977/862 Near-field probe

Abstract

A near-field microscope comprising: a probe for scattering a near-field light; light emitting device including a light source for emitting light to a sample or said probe; and light sampling device for sampling and detecting a light that includes information of the sample scattered by said probe, said microscope comprising: control device for spacing said sample or probe from a field of a near-field light generated by said light emission or disposing the sample or probe at a position that is shallow in a field of near-field light, thereby detecting a noise by said light sampling device; inserting said sample or probe deeply into a field of near-field light generated by said light emission, thereby detecting light intensity by said light sampling device; and computing device for computing a measurement result obtained by subtracting a noise from said light intensity

Claims

1. A near-field microscope comprising:

a probe for scattering a near-field light;

light emitting means including a light source for emitting light to a sample or said probe; and

light sampling means for sampling and detecting a light that includes information of the sample scattered by said probe,

said microscope comprising;

control means for spacing said sample or probe from a field of a near-field light generated by said light emission or disposing the sample or probe at a position that is shallow in a field of near-field light, thereby detecting a noise by said light sampling means;

inserting said sample or probe deeply into a field of near-field light generated by said light emission, thereby detecting light intensity by said light sampling means; and

computing means for computing a measurement result obtained by subtracting a noise from said light intensity.

2. A near-field microscope as claimed in claim 1, comprising:

spectroscopic means for spectrographically dispersing light emitted to a sample or probe by the light emitting means or light containing information on a sample scattered by said probe into light whose wavelength is within a specific range; and

analysis means for storing and analyzing measurement data for each wavelength sampled by the light sampling means, whereby a near-field spectrum on a sample can be sampled.

3. A near-field microscope as claimed in claim 2, wherein an interferometer is used for the spectroscopic means, said interferometer includes a movement mirror that carries out reciprocating motion,

said control means controls so that the sample or probe is deeply inserted into a field of a near-field light in a forward passage of said movement mirror, light intensity is detected by the light sampling means, said sample or probe is spaced from a field of a near-field light in a backward passage of the movement mirror or is disposed at a position that is shallow in a field of near-field light, and a noise is detected by said light sampling means.

4. A near-field microscope as claimed in claim 1, wherein light emitted by light emitting means is infrared light.

5. A near-field microscope as claimed in claim 4, wherein a light source contained in light emitting means is a high temperature heating element.

6. A near-field microscope as claimed in claim 4, wherein a light source for emitting light to a sample or probe is a wavelength variable laser.

7. A near-field microscope as claimed in claim 2, wherein the spectroscopic means is composed of any of a wavelength variable filter, a band pass filter having an arbitrary wavelength width, a Fourier transform type spectroscopic device or a dispersion type spectroscopic device.

8. A near-field microscope as claimed in claim 1, wherein the light emitting means carries out illumination by means of reflecting illumination that emits light directly to a sample or the probe, thereby generating a near-field light and/or by means of total reflecting illumination that brings a prism of a medium with its high refraction index into contact with a sample and reflects the light totally at a boundary of the sample and prism, thereby generating a near-field light on a sample surface.

9. A near-field microscope as claimed in claim 8, wherein the light emitting means can be selected by switching it to illumination of either one of the reflecting illumination and the total reflecting illumination.

10. A near-field microscope as claimed in claim 8, wherein the light emitting means is composed of at least a light source and a Cassegrainian mirror.

11. A near-field microscope as claimed in claim 10, wherein the shape of a medium with its high refraction index for use in total reflecting illumination is a hemispheric or analogous shape, and a focus of the Cassegrainian mirror is formed at the center of said prism plane section.

12. A near-field microscope as claimed in claim 8, wherein a medium with its high refraction index of the total reflecting prism for use in total reflecting illumination is composed of any material of ZnSe, KSR-5, Ge, Si, and diamond.

13. A near-field microscope as claimed in claim 1, wherein the light sampling means is composed of:

a Cassegrainian mirror for collecting light that contains sample information; and

a detector for detecting the light collected by said Cassegrainian mirror.

14. A near-field microscope as claimed in claim 1, comprising modulating means for modulating light emitted to a sample or probe intermittently between a light source and the sample or probe.

15. A near-field microscope as claimed in claim 13, wherein a switching reflection mirror or dichroic mirror is arranged between the Cassegrainian mirror and the detector, and is arranged so as to enable the sample and probe to be visually observed.

16. A near-field microscope as claimed in claim 3, wherein the spectroscopic means is composed of any of a wavelength variable filter, a band pass filter having an arbitrary wavelength width, a Fourier transform type spectroscopic device or a dispersion type spectroscopic device.

17. A near-field microscope as claimed in claim 9, wherein the light emitting means is composed of at least a light source and a Cassegrainian mirror.