System and method for generating super-oscillation optical needle based on sharp edge diffraction

Abstract

The present invention discloses a system and a method for generating a super-oscillation optical needle based on sharp edge diffraction. The system comprises a light source for generating monochromatic laser, a lens for focusing the laser to form collimated planar light wave in a focal depth region, a sharp edge diffraction component for absorbing the central part of the collimated planar light wave and producing a super-oscillation focused light field due to the sharp edge diffraction, an objective lens set for gathering and amplifying the super-oscillation focused light field and a camera for collecting and recording the super-oscillation focused light field gathered by the objective lens set. The present invention provides a simple and feasible system and method for generating the super-oscillation optical needle based on the sharp edge diffraction. A super-oscillation optical needle on the level of hundreds of nanometers can be generated with the combination of a sharp-edged metaldisc or ring. The system has a simple structure and flexible operation, is stable and low-cost, and has remarkable practical value.

Description

technical field [0001] The invention relates to the technical field of generation of super-oscillating optical needles, in particular to a system and method for generating super-oscillating optical needles based on sharp edge diffraction. Background technique [0002] The concept of superoscillation appears in the concept of weak measurement in quantum mechanics: the wave value of light waves obtained by local measurement in space may not exist in the range of measurement results in space as a whole. In 2006, Berry of the University of Bristol and his collaborators connected the concept of quantum super-oscillation with optical super-resolution for the first time, pointing out theoretically that using specially designed optical micro-nano structures (such as sub-wavelength grating structures) on the incident plane The amplitude of the light field is modulated, and the modulated diffractive light field can achieve sub-wavelength optical super-diffraction-limited focusing in t...

AI Technical Summary

Problems solved by technology

[0004] However, the structure of the super-oscillating components used above is very complicated, and it is generally necessary to etch thousands of nanometer-sized structural units on the metal film with a micron size. In the design process, it often needs to rely on optimization Algorithms to obtain the optimal superoscillation structure parameters, and the designed structure lacks a physical explanation for the superoscillation focused spot

In addition, from the existing research results, it can be seen that the current super-diffraction focused spot size is difficult to break through 0.3λ, and it is urgent to invent a simpler method to generate a smaller super-oscillation focused spot

Images