Nano lens and scanning microscope using the same

Abstract

The invention discloses a nanometer lens, comprising a transparent substrate and an opaque metal film formed on the substrate, wherein the metal film is provided with a plurality of concentric rings, in each ring, the inner radius r of the n-th ring counted from circle center to outer meets the equation as: r=nr, r is a preset parameter, n=1, 2 and the like, the outer radius of the n-th ring meets the equation as r+w, w is a preset parameter. The nanometer lens can obtain the resolution over traditional diffraction limit of lamda / 2, whose working distance is in a suitable range of 1 to 100 micrometers. The invention further disclseos a scanning microscope adopting the nanometer lens.

Description

Technical field [0001] The invention relates to a nano-optical device, in particular to a nano-lens and a scanning microscope used in the same. Background technique [0002] The traditional optical lens is made of glass, and its imaging resolution is limited by wavelength. The diffraction limit established by Abbe indicates that the upper limit of the resolution of the glass lens is 1 / 2 of the wavelength. In fact, the imaging resolution of a lens is determined by its point spread function (PSF). A basic function of the lens is to focus the incident parallel light to a point on the focal plane. But this point is not an ideal point, but a spot with size and intensity distribution. For example, an undisturbed circular lens focuses the spot resulting from the Airy spot, and its main lobe diameter is 1.22λ / NA, where λ is the wavelength and NA is the numerical aperture of the lens. The smaller the main lobe of the spot, the higher the imaging resolution of the lens. The intensity distr...

AI Technical Summary

Problems solved by technology

However, when designing lenses on such a microscopic scale, the relationship between various design parameters and optical performance needs to be further explored.

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